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XBee®/XBee-PRO® ZB OEM RF Modules
ZigBeeOEM RF Modules by Digi International
Firmware Versions:
- 20xx - Coordinator - AT/Transparent Operation
- 21xx - Coordinator - API Operation
- 22xx - Router - AT/Transparent Operation
- 23xx - Router - API Operation
- 28xx - End Device - AT/Transparent Operation
- 29xx - End Device - API Operation
Digi International Inc.
11001 Bren Road East
Minnetonka, MN 55343
877 912-3444 or 952 912-3444 http://www.digi.com
90000976_A
4/14/2008
XBee®/XBee‐PRO® ZB OEM RF Modules]
© 2008 Digi International, Inc. All rights reserved
No part of the contents of this manual may be transmitted or reproduced in any form or by any means without the written permission of Digi International, Inc.
ZigBee
®
is a registered trademark of the ZigBee Alliance.
XBee®/XBee‐PRO® is a registerd trademark of Digi International, Inc.
Technical Support:
Phone: (801) 765‐9885
Live Chat: www.digi.com
© 2008 Digi International, Inc.
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XBee®/XBee‐PRO® ZB OEM RF Modules
Contents
1Serial Interface Protocols 13
ZigBee Network Communications 24
1ZigBee Application-layer Addressing 24
1Data Transmission and Routing 25
XBee ZigBee Network Formation 30
1Starting an XBee Coordinator 30
1Joining a ZB Router or End Device 32
1Resetting Network Parameters 35
1Application-layer Addressing 38
© 2008 Digi Internaitonal, Inc.
1End Device Sleep Configuration 44
Remote Configuration Commands 48
1Applying Changes on Remote 48
1Digital IO Change Detection 51
5. Network Commissioning and Diagnostics 55
Commissioning Pushbutton and Associate LED
7. XBee Command Reference Tables 76
Customizing XBee Default Parameters 84
Design Considerations for Digi Drop-in Networking 87
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XBee®/XBee‐PRO® ZB OEM RF Modules
Contents
Appendix B: Agency Certifications 90
Appendix C:Migrating from ZNet 2.5 to XBee ZB
Appendix D:XBee ZB Firmware Matrix 96
Appendix E:Additional Information 98
© 2008 Digi Internaitonal, Inc.
4
1. Overview
The XBee/XBee-PRO ZB OEM RF Modules are designed to operate within the ZigBee protocol and support the unique needs of low-cost, low-power wireless sensor networks.
The modules require minimal power and provide reliable delivery of data between remote devices.
The modules operate within the ISM 2.4 GHz frequency band and are compatible with the following:
• XBee RS-232 Adapter
• XBee RS-232 PH (Power Harvester) Adapter
• XBee RS-485 Adapter
• XBee Analog I/O Adapter
• XBee Digital I/O Adapter
• XBee Sensor Adapter
• XBee USB Adapter
• XStick
• ConnectPort X Gateways
• XBee Wall Router.
The XBee/XBee-PRO ZB firmware release can be installed on XBee modules. This firmware is compatible with the ZigBee 2007 specification, while the ZNet 2.5 firmware is based on Ember's proprietary "designed for ZigBee" mesh stack (EmberZNet 2.5). ZB and ZNet 2.5 firmware are similar in nature, but not over-the-air compatible. Devices running ZNet 2.5 firmware cannot talk to devices running the ZB firmware.
© 2008 Digi International, Inc.
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XBee®/XBee‐PRO® ZB OEM RF Modules
Key Features
High Performance, Low Cost
• Indoor/Urban: up to 300’ (100 m)
• Outdoor line-of-sight: up to 1 mile (1.6 km)
• Transmit Power Output: 100 mW (20 dBm)
EIRP
• Receiver Sensitivity: -102 dBm
RF Data Rate: 250,000 bps
Advanced Networking & Security
Retries and Acknowledgements
DSSS (Direct Sequence Spread Spectrum)
Each direct sequence channel has over
65,000 unique network addresses available
Point-to-point, point-to-multipoint and peer-to-peer topologies supported
Self-routing, self-healing and fault-tolerant mesh networking
Low Power
XBee-PRO
• TX Current: 295 mA (@3.3 V)
• RX Current: 45 mA (@3.3 V)
• Power-down Current: < 1 µA @ 25 o
C
Easy-to-Use
No configuration necessary for out-of box
RF communications
AT and API Command Modes for configuring module parameters
Small form factor
Extensive command set
Free X-CTU Software
(Testing and configuration software)
Free & Unlimited Technical Support
Worldwide Acceptance
FCC Approval (USA) Refer to Appendix A [p50] for FCC Requirements.
Systems that contain XBee®/XBee-PRO® ZB RF Modules inherit Digi Certifications.
ISM (Industrial, Scientific & Medical) 2.4 GHz frequency band
Manufactured under ISO 9001:2000 registered standards
XBee®/XBee-PRO® ZB RF Modules are optimized for use in US, Canada, Australia,
Israel and Europe (contact MaxStream for complete list of agency approvals).
Specifications
Table 1‐01. Specifications of the XBee®/XBee‐PRO® ZB OEM RF Module
Specification XBee XBee PRO
Performance
Indoor/Urban Range
Outdoor RF line-of-sight Range
Transmit Power Output
RF Data Rate
Serial Interface Data Rate
(software selectable)
Receiver Sensitivity up to 133 ft. (40 m) up to 400 ft. (120 m)
2mW (+3dBm), boost mode enabled
1.25mW (+1dBm), boost mode disabled
250,000 bps
1200 - 230400 bps
(non-standard baud rates also supported)
-96 dBm, boost mode enabled
-95 dBm, boost mode disabled up to 300 ft. (100 m) up to 1 mile (1.6 km)
50mW (+17 dBm)
10mW (+10 dBm) for International variant
250,000 bps
1200 - 230400 bps
(non-standard baud rates also supported)
-102 dBm
Power Requirements
© 2008 Digi International, Inc.
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XBee®/XBee‐PRO® ZB OEM RF Modules
Table 1‐01. Specifications of the XBee®/XBee‐PRO® ZB OEM RF Module
Specification
Supply Voltage
XBee XBee PRO
3.0 - 3.4 V
Operating Current (Transmit, max output power)
Operating Current (Receive))
Idle Current (Receiver off)
2.1 - 3.6 V
40mA (@ 3.3 V, boost mode enabled)
35mA (@ 3.3 V, boost mode disabled)
40mA (@ 3.3 V, boost mode enabled)
38mA (@ 3.3 V, boost mode disabled)
15mA
295mA (@3.3 V)
45 mA (@3.3 V)
15mA
< 1 uA @ 25 o
C < 1 uA @ 25 o
C
Power-down Current
General
Operating Frequency Band
Dimensions
Operating Temperature
Antenna Options
Networking & Security
ISM 2.4 GHz
0.960” x 1.087” (2.438cm x 2.761cm)
-40 to 85º C (industrial)
ISM 2.4 GHz
0.960 x 1.297 (2.438cm x 3.294cm)
-40 to 85º C (industrial)
Integrated Whip, Chip, RPSMA, or U.FL Connector* Integrated Whip, Chip, RPSMA, or U.FL Connector*
Supported Network Topologies
Number of Channels
Addressing Options
Point-to-point, Point-to-multipoint, Peer-to-peer, and
Mesh
Point-to-point, Point-to-multipoint, Peer-to-peer, and
Mesh
16 Direct Sequence Channels
PAN ID and Addresses, Cluster IDs and Endpoints
(optional)
13 Direct Sequence Channels
PAN ID and Addresses, Cluster IDs and Endpoints
(optional)
Agency Approvals
United States (FCC Part 15.247)
Industry Canada (IC)
Europe (CE)
RoHS
FCC ID: OUR-XBEE2
IC: 4214A-XBEE2
ETSI
Compliant
FCC ID: MCQ-XBEEPRO2
IC: 1846A-XBEEPRO2
ETSI
Compliant
© 2008 Digi International, Inc.
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XBee®/XBee‐PRO® ZB OEM RF Modules
Mechanical Drawings
Figure 1‐01. Mechanical drawings of the XBee®/XBee‐PRO® ZB OEM RF Modules (antenna options not shown)
.
Figure 1‐02. Mechanical Drawings for the RPSMA Variant
© 2008 Digi International, Inc.
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XBee®/XBee‐PRO® ZB OEM RF Modules
Mounting Considerations
The XBee modules were designed to mount into a receptacle (socket) and therefore does not require any soldering when mounting it to a board. The XBee-PRO Development Kits contain RS-
232 and USB interface boards which use two 20-pin receptacles to receive modules.
Figure 1‐03. XBee‐PRO Module Mounting to an RS‐232 Interface Board.
The receptacles used on Digi development boards are manufactured by Century Interconnect.
Several other manufacturers provide comparable mounting solutions; however, Digi currently uses the following receptacles:
• Through-hole single-row receptacles -
Samtec P/N: MMS-110-01-L-SV (or equivalent)
• Surface-mount double-row receptacles -
Century Interconnect P/N: CPRMSL20-D-0-1 (or equivalent)
• Surface-mount single-row receptacles -
Samtec P/N: SMM-110-02-SM-S
Digi also recommends printing an outline of the module on the board to indicate the orientation the module should be mounted.
© 2008 Digi International, Inc.
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XBee®/XBee‐PRO® ZB OEM RF Modules
Pin Signals
Figure 1‐04. XBee®/XBee‐PRO® ZB RF Module Pin Number
(top sides shown ‐ shields on bottom)
Table 1‐02. Pin Assignments for the XBee‐PRO Modules
(Low‐asserted signals are distinguished with a horizontal line above signal name.)
Pin #
7
8
5
6
3
4
1
2
9
10
11
12
13
14
15
16
17
18
19
20
Name
VCC
DOUT
DIN / CONFIG
DIO12
RESET
PWM0 / RSSI / DIO10
PWM / DIO11
[reserved]
DTR / SLEEP_RQ/ DIO8
GND
DIO4
CTS / DIO7
ON / SLEEP / DIO9
VREF
Associate / DIO5
RTS / DIO6
AD3 / DIO3
AD2 / DIO2
AD1 / DIO1
AD0 / DIO0 / Commissioning
Button
Direction
-
Output
Input
Either
Input
Either
Either
-
Either
-
Either
Either
Output
Input
Either
Either
Either
Either
Either
Either
Description
Power supply
UART Data Out
UART Data In
Digital I/O 12
Module Reset (reset pulse must be at least 200 ns)
PWM Output 0 / RX Signal Strength Indicator / Digital IO
Digital I/O 11
Do not connect
Pin Sleep Control Line or Digital IO 8
Ground
Digital I/O 4
Clear-to-Send Flow Control or Digital I/O 7
Module Status Indicator or Digital I/O 9
Not used on this module. For compatibility with other XBee modules, we recommend connecting this pin to a voltage reference if Analog sampling is desired. Otherwise, connect to
GND.
Associated Indicator, Digital I/O 5
Request-to-Send Flow Control, Digital I/O 6
Analog Input 3 or Digital I/O 3
Analog Input 2 or Digital I/O 2
Analog Input 1 or Digital I/O 1
Analog Input 0, Digital IO 0, or Commissioning Button
Design Notes:
• Minimum connections: VCC, GND, DOUT & DIN
• Minimum connections to support serial firmware upgrades: VCC, GND, DIN, DOUT, RTS & DTR
• Signal Direction is specified with respect to the module
• Module includes a 30k Ohm resistor attached to RESET
• Several of the input pull-ups can be configured using the PR command
• Unused pins should be left disconnected
• Pin 20 can be connected to a push button (pin grounded when closed) to support the commissioning push button functionality. See “Commissioning Pushbutton and Associate LED” for details.
© 2008 Digi International, Inc.
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XBee®/XBee‐PRO® ZB OEM RF Modules
Electrical Characteristics
Table 1‐03. DC Characteristics of the XBee‐PRO (VCC = 3.0 ‐ 3.4 VDC).
Symbol
VIL
V
IH
V
OL
V
OH
II
IN
Parameter
Input Low Voltage
Input High Voltage
Output Low Voltage
Output High Voltage
Input Leakage Current
Condition
All Digital Inputs
All Digital Inputs
I
OL
= 2 mA, VCC >= 2.7 V
I
OH
= -2 mA, VCC >= 2.7 V
V
IN
= VCC or GND, all inputs, per pin
Min
-
0.8 * VCC
-
0.82*VCC
-
Typical
-
-
-
-
-
Max
0.2 * VCC
-
0.18*VCC
-
0.5uA
Units
V
V
V
V uA
© 2008 Digi International, Inc.
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2. RF Module Operation
Serial Communications
The XBee OEM RF Modules interface to a host device through a logic-level asynchronous serial port. Through its serial port, the module can communicate with any logic and voltage compatible
UART; or through a level translator to any serial device (For example: Through a Digi proprietary
RS-232 or USB interface board).
UART Data Flow
Devices that have a UART interface can connect directly to the pins of the RF module as shown in the figure below.
Figure 2‐01. System Data Flow Diagram in a UART‐interfaced environment
(Low‐asserted signals distinguished with horizontal line over signal name.)
DIN (data in)
DOUT (data out)
DIN (data in)
DOUT (data out)
Serial Data
Data enters the module UART through the DIN (pin 3) as an asynchronous serial signal. The signal should idle high when no data is being transmitted.
Each data byte consists of a start bit (low), 8 data bits (least significant bit first) and a stop bit
(high). The following figure illustrates the serial bit pattern of data passing through the module.
Figure 2‐02. UART data packet 0x1F (decimal number ʺ31ʺ) as transmitted through the RF module
Example Data Format is 8‐N‐1 (bits ‐ parity ‐ # of stop bits)
The module UART performs tasks, such as timing and parity checking, that are needed for data communications. Serial communications depend on the two UARTs to be configured with compatible settings (baud rate, parity, start bits, stop bits, data bits).
Serial Buffers
The XBee modules maintain small buffers to collect received serial and RF data, which is illustrated in the figure below. The serial receive buffer collects incoming serial characters and holds them until they can be processed. The serial transmit buffer collects data that is received via the RF link that will be transmitted out the UART.
© 2008 Digi International, Inc.
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XBee®/XBee‐PRO® ZB OEM RF Modules
Figure 2‐03. Internal Data Flow Diagram
DIN
CTS
Serial
Receiver
Buffer
RF TX
Buffer
Processor
Transmitter
DOUT
RTS
Serial Transmit
Buffer
RF RX
Buffer
Receiver
RF Switch
Antenna
Port
Serial Receive Buffer
When serial data enters the RF module through the DIN Pin (pin 3), the data is stored in the serial receive buffer until it can be processed. Under certain conditions, the module may not be able to process data in the serial receive buffer immediately. If large amounts of serial data are sent to the module, CTS flow control may be required to avoid overflowing the serial receive buffer.
Cases in which the serial receive buffer may become full and possibly overflow:
1.If the module is receiving a continuous stream of RF data, the data in the serial receive buffer will not be transmitted until the module is no longer receiving RF data.
2.If the module is transmitting an RF data packet, the module may need to discover the destination address or establish a route to the destination. After transmitting the data, the module may need to retransmit the data if an acknowledgment is not received, or if the transmission is a broadcast. These issues could delay the processing of data in the serial receive buffer.
Serial Transmit Buffer
When RF data is received, the data is moved into the serial transmit buffer and sent out the UART.
If the serial transmit buffer becomes full enough such that all data in a received RF packet won’t fit in the serial transmit buffer, the entire RF data packet is dropped.
Cases in which the serial transmit buffer may become full resulting in dropped RF packets
1. If the RF data rate is set higher than the interface data rate of the module, the module could receive data faster than it can send the data to the host.
2. If the host does not allow the module to transmit data out from the serial transmit buffer because of being held off by hardware flow control.
Serial Flow Control
The RTS and CTS module pins can be used to provide RTS and/or CTS flow control. CTS flow control provides an indication to the host to stop sending serial data to the module. RTS flow control allows the host to signal the module to not send data in the serial transmit buffer out the uart. RTS and CTS flow control are enabled using the D6 and D7 commands.
CTS Flow Control
If CTS flow control is enabled (D7 command), when the serial receive buffer is 17 bytes away from being full, the module de-asserts CTS (sets it high) to signal to the host device to stop sending serial data. CTS is re-asserted after the serial receive buffer has 34 bytes of space.
© 2008 Digi International, Inc.
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XBee®/XBee‐PRO® ZB OEM RF Modules
RTS Flow Control
If RTS flow control is enabled (D6 command), data in the serial transmit buffer will not be sent out the DOUT pin as long as RTS is de-asserted (set high). The host device should not de-assert RTS for long periods of time to avoid filling the serial transmit buffer. If an RF data packet is received, and the serial transmit buffer does not have enough space for all of the data bytes, the entire RF data packet will be discarded.
Serial Interface Protocols
The XBee modules support both transparent and API (Application Programming Interface) serial interfaces.
Transparent Operation
When operating in transparent mode, the modules act as a serial line replacement. All UART data received through the DIN pin is queued up for RF transmission. When RF data is received, the data is sent out through the DOUT pin. The module configuration parameters are configured using the
AT command mode interface.
Data is buffered in the serial receive buffer until one of the following causes the data to be packetized and transmitted:
• No serial characters are received for the amount of time determined by the RO (Packetization
Timeout) parameter. If RO = 0, packetization begins when a character is received.
• The Command Mode Sequence (GT + CC + GT) is received. Any character buffered in the serial receive buffer before the sequence is transmitted.
• The maximum number of characters that will fit in an RF packet is received
RF modules that contain the following firmware versions will support Transparent Mode:
1.0xx (coordinator) and 1.2xx (router/end device).
API Operation
API operation is an alternative to transparent operation. The frame-based API extends the level to which a host application can interact with the networking capabilities of the module. When in API mode, all data entering and leaving the module is contained in frames that define operations or events within the module.
Transmit Data Frames (received through the DIN pin (pin 3)) include:
• RF Transmit Data Frame
• Command Frame (equivalent to AT commands)
Receive Data Frames (sent out the DOUT pin (pin 2)) include:
• RF-received data frame
• Command response
• Event notifications such as reset, associate, disassociate, etc.
The API provides alternative means of configuring modules and routing data at the host application layer. A host application can send data frames to the module that contain address and payload information instead of using command mode to modify addresses. The module will send data frames to the application containing status packets; as well as source, and payload information from received data packets.
The API operation option facilitates many operations such as the examples cited below:
->Transmitting data to multiple destinations without entering Command Mode
->Receive success/failure status of each transmitted RF packet
->Identify the source address of each received packet
RF modules that contain the following firmware versions will support API operation: 1.1xx
(coordinator) and 1.3xx (router/end device).
© 2008 Digi International, Inc.
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XBee®/XBee‐PRO® ZB OEM RF Modules
A Comparison of Transparent and API Operation
The following table compares the advantages of transparent and API modes of operation:
Transparent Operation Features
Simple Interface All received serial data is transmitted unless the module is in command mode.
Easy to support It is easier for an application to support transparent operation and command mode
API Operation Features
Easy to manage data transmissions to multiple destinations
Transmitting RF data to multiple remotes only requires changing the address in the API frame. This process is much faster than in transparent operation where the application must enter AT command mode, change the address, exit command mode, and then transmit data.
Each API transmission can return a transmit status frame indicating the success or reason for failure.
Received data frames indicate the sender's address
All received RF data API frames indicate the source address.
Advanced ZigBee addressing support
Advanced networking diagnostics
Remote Configuration
API transmit and receive frames can expose ZigBee addressing fields including source and destination endpoints, cluster ID and profile ID. This makes it easy to support ZDO commands and public profile traffic.
API frames can provide indication of IO samples from remote devices, and node identification messages.
Set / read configuration commands can be sent to remote devices to configure them as needed using the API.
As a general rule of thumb, API firmware is recommended when a device:
• sends RF data to multiple destinations
• sends remote configuration commands to manage devices in the network
• receives IO samples from remote devices
• receives RF data packets from multiple devices, and the application needs to know which device sent which packet
• must support multiple ZigBee endpoints, cluster IDs, and/or profile IDs
• uses the ZigBee Device Profile services.
If the above conditions do not apply (i.e. a sensor node, router, or a simple application), then AT firmware might be suitable.
© 2008 Digi International, Inc.
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XBee®/XBee‐PRO® ZB OEM RF Modules
Modes of Operation
Idle Mode
When not receiving or transmitting data, the RF module is in Idle Mode. During Idle Mode, the RF module is also checking for valid RF data. The module shifts into the other modes of operation under the following conditions:
• Transmit Mode (Serial data in the serial receive buffer is ready to be packetized)
• Receive Mode (Valid RF data is received through the antenna)
• Sleep Mode (End Devices only)
• Command Mode (Command Mode Sequence is issued)
Transmit Mode
When serial data is received and is ready for packetization, the RF module will exit Idle Mode and attempt to transmit the data. The destination address determines which node(s) will receive the data.
Prior to transmitting the data, the module ensures that a 16-bit network address and route to the destination node have been established.
If the destination 16-bit network address is not known, network address discovery will take place.
If a route is not known, route discovery will take place for the purpose of establishing a route to the destination node. If a module with a matching network address is not discovered, the packet is discarded. The data will be transmitted once a route is established. If route discovery fails to establish a route, the packet will be discarded.
Figure 2‐04. Transmit Mode Sequence
Successful
Transmission
Idle Mode
New
Transmission
16-bit Network
Address Known?
No
Yes
16-bit Network
Address Discovery
Route Known?
Yes
No
Transmit Data
Route Discovery
16-bit Network
Address Discovered?
Yes
No
Route Discovered?
Yes
No
Data Discarded
© 2008 Digi International, Inc.
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XBee®/XBee‐PRO® ZB OEM RF Modules
When data is transmitted from one node to another, a network-level acknowledgement is transmitted back across the established route to the source node. This acknowledgement packet indicates to the source node that the data packet was received by the destination node. If a network acknowledgement is not received, the source node will re-transmit the data.
It is possible in rare circumstances for the destination to receive a data packet, but for the source to not receive the network acknowledgment. In this case, the source will retransmit the data, which could cause the destination to receive the same data packet multiple times. The XBee modules do not filter out duplicate packets. The application should include provisions to address this potential issue
See Data Transmission and Routing in chapter 3 for more information.
Receive Mode
If a valid RF packet is received, the data is transferred to the serial transmit buffer.
Command Mode
To modify or read RF Module parameters, the module must first enter into Command Mode - a state in which incoming serial characters are interpreted as commands. Refer to the API Mode section in Chapter 7 for an alternate means of configuring modules.
AT Command Mode
To Enter AT Command Mode:
Send the 3-character command sequence “+++” and observe guard times before and after the command characters. [Refer to the “Default AT Command Mode Sequence” below.]
Default AT Command Mode Sequence (for transition to Command Mode):
• No characters sent for one second [GT (Guard Times) parameter = 0x3E8]
• Input three plus characters (“+++”) within one second [CC (Command Sequence Character) parameter = 0x2B.]
• No characters sent for one second [GT (Guard Times) parameter = 0x3E8]
Once the AT command mode sequence has been issued, the module sends an "OK\r" out the
DOUT pin. The "OK\r" characters can be delayed if the module has not finished transmitting received serial data.
When command mode has been entered, the command mode timer is started (CT command), and the module is able to receive AT commands on the DIN pin.
All of the parameter values in the sequence can be modified to reflect user preferences.
NOTE: Failure to enter AT Command Mode is most commonly due to baud rate mismatch. By default, the BD (Baud Rate) parameter = 3 (9600 bps).
To Send AT Commands:
Send AT commands and parameters using the syntax shown below.
Figure 2‐05. Syntax for sending AT Commands
To read a parameter value stored in the RF module’s register, omit the parameter field.
The preceding example would change the RF module Destination Address (Low) to “0x1F”. To store the new value to non-volatile (long term) memory, subsequently send the WR (Write) command.
© 2008 Digi International, Inc.
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XBee®/XBee‐PRO® ZB OEM RF Modules
For modified parameter values to persist in the module’s registry after a reset, changes must be saved to non-volatile memory using the WR (Write) Command. Otherwise, parameters are restored to previously saved values after the module is reset.
Command Response
When a command is sent to the module, the module will parse and execute the command. Upon successful execution of a command, the module returns an “OK” message. If execution of a command results in an error, the module returns an “ERROR” message.
Applying Command Changes
Any changes made to the configuration command registers through AT commands will not take effect until the changes are applied. For example, sending the BD command to change the baud rate will not change the actual baud rate until changes are applied. Changes can be applied in one of the following ways:
• The AC (Apply Changes) command is issued.
• AT command mode is exited.
To Exit AT Command Mode:
1. Send the ATCN (Exit Command Mode) command (followed by a carriage return).
[OR]
2. If no valid AT Commands are received within the time specified by CT (Command Mode
Timeout) Command, the RF module automatically returns to Idle Mode.
For an example of programming the RF module using AT Commands and descriptions of each configurable parameter, refer to the "Examples" and "XBee Command Reference Tables" chapters.
Sleep Mode
Sleep modes allow the RF module to enter states of low power consumption when not in use. The
XBee OEM RF modules support both pin sleep (sleep mode entered on pin transition) and cyclic sleep (module sleeps for a fixed time). XBee sleep modes are discussed in detail in section 5.3.
© 2008 Digi International, Inc.
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3. ZigBee Networks
ZigBee Network Formation
ZigBee networks are called personal area networks or PANs. Each network is defined with a unique
PAN identifier (PAN ID). XBee ZB supports both a 64-bit (extended) PAN ID and a 16-bit PAN ID.
The 16-bit PAN ID is used in all data transmissions. The 64-bit PAN ID is used during joining, and to resolve 16-bit PAN ID conflicts that may occur.
ZigBee defines three different device types: coordinator, router, and end devices. An example of such a network is shown below:
Figure 3‐01. Node Types / Sample of a Basic ZigBee Network Topology
A coordinator has the following characteristics: it
• Selects a channel and PAN ID (both 64-bit and 16-bit) to start the network
• Can allow routers and end devices to join the network
• Can assist in routing data
• Cannot sleep--should be mains powered.
A router has the following characteristics: it
• Must join a ZigBee PAN before it can transmit, receive, or route data
• After joining, can allow routers and end devices to join the network
• After joining, can assist in routing data
• Cannot sleep--should be mains powered.
A end device has the following characteristics: it
• Must join a ZigBee PAN before it can transmit or receive data
• Cannot allow devices to join the network
• Must always transmit and receive RF data through its parent. Cannot route data.
• Can enter low power modes to conserve power and can be battery-powered.
In ZigBee networks, the coordinator must select a PAN ID (64-bit and 16-bit) and channel to start a network. After that, it behaves essentially like a router. The coordinator and routers can allow other devices to join the network and can route data.
After an end device joins a router or coordinator, it must be able to transmit or receive RF data through that router or coordinator. The router or coordinator that allowed an end device to join becomes the "parent" of the end device. Since the end device can sleep, the parent must be able to buffer or retain incoming data packets destined for the end device until the end device is able to wake and receive the data.
© 2008 Digi International, Inc.
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XBee®/XBee‐PRO® ZB OEM RF Modules
ZigBee PANs
ZigBee networks are formed when a coordinator first selects a channel and PAN ID. After the coordinator has started the PAN, routers and end devices may join the PAN. The PAN ID is selected by the coordinator when it starts the PAN. Routers and end devices become a part of the PAN
(and inherit the coordinator’s PAN ID) when they join a PAN.
ZigBee supports mesh routing in the network, allowing data packets to traverse multiple nodes
(multiple "hops") in order to reach the destination node. This allows ZigBee nodes to be spread out over a large region, and still support communications among all devices in the network.
All devices in a ZigBee network receive a 16-bit address (network address) when they join a PAN.
The 16-bit address of the coordinator is always 0.
Starting a PAN
Since the coordinator is responsible for starting a ZigBee network, all ZigBee networks must have a coordinator present initially. To start a PAN, the coordinator performs a series of scans to discover the level of RF activity on different channels (energy scan), and to discover any nearby operating PANs (PAN scan). Energy Scan
When a coordinator comes up for the first time, it performs an energy scan on multiple channels
(frequencies) to detect energy levels on each channel. Channels with excessive detected energy levels are removed from its list of potential channels to start on.
Figure 3‐02. Potential Channels
List of Potential Channels
1 2 3 4 . . . 14 15 16
Performing an energy scan allows the coordinator to avoid starting on channels with high energy levels.
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When the energy scan completes, the coordinator scans the remaining quiet channels (found in the energy scan) for existing PANs. To do this, the coordinator sends a broadcast, one-hop beacon request. Any nearby coordinators and routers will respond to the beacon request by sending a beacon frame back to the coordinator. The beacon frame contains information about the PAN the sender is on, including the PAN identifier (PAN ID), and whether or not the device is allowing joining. (The PAN scan is more commonly called an active scan or a beacon scan.)
PAN Scan
Figure 3‐03. PAN Scans
PAN Scan
Beacon Request
Router
Beacon Request
Beacon
New
Coordinator
Beacon Request
Beacon
Coordinator
A PAN Scan allows the coordinator to detect nearby PAN IDs to avoid duplicating existing PAN IDs
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Once the coordinator has completed the energy and PAN scans, it parses all received beacons and attempts to start on an unused PAN ID and channel. When the coordinator starts a PAN, it can then allow routers and/or end devices to join the PAN. A coordinator retains the channel and PAN
ID attributes through power cycle or reset events.
Joining a PAN
Router and end device types must discover and join a ZigBee PAN. To do this, they first issue a
PAN scan, just like the coordinator does when it starts a PAN. From the PAN scan, the router or end device receives a list of beacons from nearby ZigBee devices. The router or end device parses this list to find a valid ZigBee network to join.
Routers and end devices can be configured to join any ZigBee PAN, or to only join a PAN with a certain PAN ID. However, they must always find a coordinator or router that is allowing joins.
Figure 3‐04. Joining a PAN
Beacon R equest
Beacon Request
Beacon*
R outer attaem pting to join
Beacon Request
Beacon*
Coordinator
Router
A ssociation Request
A ssociation Response
* Each beacon contains the follow ing attributes:
P AN ID = xx
Allow join = true/false
A router or end device sends a beacon request to discover nearby Zigbee netw orks . If a device is found that is operating on a valid Zigbee netw ork, that is allow ing joins, the router or end device sends an association request to that device to attem pt to join the netw ork
Once a joining device (router or end device) discovers a device operating on a valid ZigBee network that is allowing joining, it attempts to join the PAN by sending an association request to that device.
Allowing Joining
The coordinator and all routers can allow new routers and end devices to join to them. Whether or not a particular coordinator or router will allow a new device to join depends upon two things:
• its permit-joining attribute (if joins are allowed)
• the number of end device children it already has
Permit-Joining Attribute
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The coordinator and all routers have a permit-joining attribute. This attribute on a coordinator and any joined routers can be configured to always allow joins, allow joins for a short time, or to not allow any more joins. In order for a new device to join the network, this attribute must be set on a nearby device such that joins are enabled.
End Device Children
Since end devices rely on their parent router or coordinator to buffer incoming RF packets, the coordinator and each router can support a finite number of end device children. Once that number of end devices has joined a particular router or coordinator, the device can no longer allow end devices to join to it.
Security
If security is enabled, the coordinator will start up using a 128-bit AES encryption key. Only devices that have the same security key can communicate on the PAN. Routers and end devices that will join a secure PAN must obtain the correct security key. The security key can be obtained in one of two ways:
• pre-installation
• key is received over-the-air (in the clear) during joining.
XBee ZB defines a network key and a link key (trust center link key). Both keys are 128-bits and are used to apply AES encryption to RF packets.
Network Security Key
The coordinator selects a network security key when it forms the network. Joining routers and end devices obtain the key when they join the network. The network key can be transmitted securely to joining devices if they have a pre-installed link key that is shared by the coordinator.
Otherwise, the coordinator will transmit the network key unencrypted to joining devices.
The network security key is used to apply 128-bit AES encryption to the payload portion of all network level transmissions. This includes APS headers and data including route requests, route replies, APS commands, ZDO commands, application data packets, etc. All network layer packets are encrypted and authenticated using AES-128. A 4-byte message integrity code (MIC) is appended to the end of the packet.
Network security supports a 32-bit frame counter. The counter is incremented for each transmission sent by the device. (Each device maintains the last received frame counter value for all of its neighbors.) The frame counter cannot wrap to 0. If a packet is received from a neighbor with a frame counter less than or equal to the last received frame counter, the packet is dropped.
The frame counter is reset to 0 when the network key is updated.
Network layer security is applied on a hop-by-hop basis. As each node along a route receives an encrypted packet, it decrypts and authenticates the packet before processing it. When forwarding the packet to the next hop, the node re-encrypts the packet with its own network security parameters (source address and frame counter).
Because of the hop-by-hop overhead to decrypt, authenticate, and re-encrypt data, transmitting data in a secure network has added latency over transmissions in an unsecured network. Also, due to the additional bytes required to for secure data transmissions, the maximum data packet size is reduced when security is enabled.
APS Link Key
The ZigBee APS layer provides end-to-end security between source and destination devices using a link key that is only known between the two devices. APS security encrypts the APS payload
(which includes the data payload) and authenticates the APS header, APS security header, and the
APS payload. A 4-byte message integrity code (MIC) is appended to the end of the APS data.
After encrypting and authenticating a transmission at the APS layer, the packet is passed to the network layer for processing. APS security is only encrypted by the source and decrypted by the destination - not by each hop.
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Network Key Updates
As mentioned previously, network security requires a 32-bit frame counter be maintained by each device. This frame counter is incremented after each transmission and cannot wrap to 0. If a neighbor receives a transmission with a frame counter that is less than or equal to the last received frame counter, the packet will be discarded.
To prevent an eventual lockup where the frame counter on a device reaches 0xFFFFFFFF, the network key should be periodically updated (changed) on all devices in the network.
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ZigBee Network Communications
Zigbee supports device addressing and application layer addressing. Device addressing specifies the destination address of the device a packet is destined to. Application layer addressing indicates a particular application recipient, known as a Zigbee endpoint, along with a message type field called a Cluster ID.
ZigBee Device Addressing
The 802.15.4 protocol upon which the ZigBee protocol is built specifies two address types:
• 16-bit network addresses
• 64-bit Addresses
16-bit Network Addresses
A 16-bit network address is assigned to a node when the node joins a network. The network address is unique to each node in the network. However, network addresses are not static - it can change.
The following two conditions will cause a node to receive a new network address:
1. If an end device cannot communicate with its parent it may need to leave the network and rejoin to find a new parent.
2. If the device type changes from router to end device, or vice-versa, the device will leave the network and rejoin as the new device type.
ZigBee requires that data be sent to the 16-bit network address of the destination device. This requires that the 16-bit address be discovered before transmitting data. See 3.2.3 Network
Address Discovery for more information.
64-bit Addresses
Each node contains a unique 64-bit address. The 64-bit address uniquely identifies a node and is permanent.
ZigBee Application-layer Addressing
The ZigBee application layers define endpoints and cluster identifiers (cluster IDs) that are used to address individual services or applications on a device. An endpoint is a distinct task or application that runs on a ZigBee device, similar to a TCP port. Each ZigBee device may support one or more endpoints. Cluster IDs define a particular function or action on a device. Cluster IDs in the ZigBee home controls lighting profile, for example, would include actions such as “TurnLightOn”,
“TurnLightOff”, “DimLight”, etc.
Suppose a single radio controls a light dimmer and one or more light switches. The dimmer and switches could be assigned to different endpoint values. To send a message to the dimmer, a remote radio would transmit a message to the dimmer endpoint on the radio. In this example, the radio might support cluster IDs to “TurnLightOn”, “TurnLightOff”, or “DimLight”. Thus, for radio A to turn off a light on radio B, radio A would send a transmission to the light switch endpoint on radio B, using cluster ID “TurnLightOff”. This is shown in the figure below.
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Figure 3‐05. ZigBee Layer‐Addressing Example
ZigBee Device A
Endpoint 1
ZigBee Device B
Endpoint 40
Endpoint 2
Endpoint 41
(radio B)
Endpoint 3
(radio A)
Endpoint 42
Cluster ID = TurnLightOff
Data Transmission and Routing
All data packets are addressed using both device and application layer addressing fields. Data can be sent as a broadcast, or unicast transmission.
Broadcast Transmissions
Broadcast transmissions within the ZigBee protocol are intended to be propagated throughout the entire network such that all nodes receive the transmission. To accomplish this, all devices that receive a broadcast transmission will retransmit the packet 3 times.
Figure 3‐06. Broadcast Data Transmission
E
E
E
R
R R
C
R R
E
Legend
C =C oordinator
R =R outer
E =E nd D evice
E
R
E
Each node that transmits the broadcast will also create an entry in a local broadcast transmission table. This entry is used to keep track of each received broadcast packet to ensure the packets are
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not endlessly transmitted. Each entry persists for 8 seconds. The broadcast transmission table holds 8 entries.
For each broadcast transmission, the ZigBee stack must reserve buffer space for a copy of the data packet. This copy is used to retransmit the packet as needed.Large broadcast packets will require more buffer space.
Since broadcast transmissions are retransmitted by each device in the network, broadcast messages should be used sparingly.
Unicast Transmissions
Unicast ZigBee transmissions are always addressed to the 16-bit address of the destination device. However, only the 64-bit address of a device is permanent; the 16-bit address can change.
Therefore, ZigBee devices may employ network address discovery to identify the current 16-bit address that corresponds to a known 64-bit address, and route discovery to establish a route.
Network Address Discovery
Data transmissions are always sent to the 16-bit network address of the destination device.
However, since the 64-bit address is unique to each device and is generally known, ZigBee devices must discover the network address that was assigned to a particular device when it joined the PAN before they can transmit data.
To do this, the device initiating a transmission sends a broadcast network address discovery transmission throughout the network. This packet contains the 64-bit address of the device the initiator needs to send data to. Devices that receive this broadcast transmission check to see if their 64-bit address matches the 64-bit address contained in the broadcast transmission. If the addresses match, the device sends a response packet back to the initiator, providing the network address of the device with the matching 64-bit address. When this response is received, the initiator can then transmit data.
Route Discovery
ZigBee employs mesh routing to establish a route between the source device and the destination.
Mesh routing allows data packets to traverse multiple nodes (hops) in a network to route data from a source to a destination. Routers and coordinators can participate in establishing routes between source and destination devices using a process called route discovery. The Route discovery process is based on the AODV (Ad-hoc On-demand Distance Vector routing) protocol.
Figure 3‐07. Sample Transmission Through a Mesh Network
R
E
R
E
R
R
R
C
E
R
R
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AODV (Ad-hoc On-demand Distance Vector) Routing Algorithm
Routing under the AODV protocol is accomplished using tables in each node that store the next hop (intermediary node between source and destination nodes) for a destination node. If a next hop is not known, route discovery must take place in order to find a path. Since only a limited number of routes can be stored on a Router, route discovery will take place more often on a large network with communication between many different nodes.
Table 3‐01.
Node Destination Address Next Hop Address
R3
C
R5
Router 6
Router 6
Router 6
Coordinator
Router 5
Router 6
When a source node must discover a route to a destination node, it sends a broadcast route request command. The route request command contains the source network address, the destination network address and a path cost field (a metric for measuring route quality). As the route request command is propagated through the network (refer to the Broadcast Transmission), each node that re-broadcasts the message updates the path cost field and creates a temporary entry in its route discovery table.
Figure 3‐08. Sample Route Request (Broadcast) Transmission Where R3 is Trying to Discover a Route to R6t
R3 R4
R1
C
R6
R2 R5
When the destination node receives a route request, it compares the ‘path cost’ field against previously received route request commands. If the path cost stored in the route request is better than any previously received, the destination node will transmit a route reply packet to the node that originated the route request. Intermediate nodes receive and forward the route reply packet to the source node (the node that originated route request).
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Figure 3‐09. Route Reply Sample Route Reply (Unicast) Where R6 Sends a Route Reply to R3.
R3
R4
R1
C
R6
R2 R5
Legend
First Route Reply
Second Route Reply
Note: R6 could send multiple replies if it identifies a better route.
Retries and Acknowledgments
ZigBee includes acknowledgment packets at both the Mac and Application Support (APS) layers.
When data is transmitted to remote device, it may traverse multiple hops to reach the destination.
As data is transmitted from one node to its neighbor, an acknowledgment packet (Ack) is transmitted in the opposite direction to indicate that the transmission was successfully received. If the Ack is not received, the transmitting device will retransmit the data, up to 4 times. This Ack is called the Mac layer acknowledgment.
In addition, the device that originated the transmission expects to receive an acknowledgment packet (Ack) from the destination device. This Ack will traverse the same path that the data traversed, but in the opposite direction. If the originator fails to receive this Ack, it will retransmit the data, up to 2 times until an Ack is received. This Ack is called the ZigBee APS layer acknowledgment.
Refer to the ZigBee specification for more details.
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Figure 3‐010.Unicast Data Transmission
E
R
R
E
R
R
R
C
E
Legend
Data Transmission
One Network ACK: Destination to Source
Mac ACK
R
R
Many to One Transmissions
Since ZigBee unicast transmissions may require some combination of broadcast network address discovery and/or route discovery, having large numbers of devices unicasting data to a single gateway or collector device may not scale well to large networks. For example, if many devices send route discoveries simultaneously, a large network could become flooded with broadcast transmissions. In addition, the collector device would have to support a large routing table to store reverse routes for each device in the network. If the routing table were smaller than the number of remotes, the collector could not store enough routes and would have to perform regular route discoveries.
To work around this potential problem, ZigBee includes provisions to support many-to-one transmissions, where many devices in a network can all transmit data to a central gateway or collector device without causing a flood of route discoveries. To accomplish this, the collector device sends a periodic broadcast transmission identifying itself as a collector device. All other devices that receive this broadcast transmission create a reverse routing table entry back to the collector. When the remote devices transmit data to the collector, they first transmit a route record frame (that records the entire route from the remote to the collector) before transmitting the data. The route record frame provides the collector with the entire route to each remote it receives data from. The collector can use the information in the route record frames to store return routes. This process effectively establishes routes between the collector and all devices in the network using a single broadcast transmission instead of many route discoveries. ZigBee many-to-one routing can support one or more collector devices.
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4. XBee ZigBee Networks
The XBee modules are based off the ZigBee 2007 specification. This chapter describes how to configure the module networking, addressing, and security parameters to create operational
ZigBee networks.
XBee ZigBee Network Formation
To create a ZigBee network, a coordinator must be started on a channel and PAN ID (64-bitand
16-bit). Once the coordinator has started, routers and end devices can join thenetwork. Network formation is governed by the EI (extended PAN ID), SC (scan channels),and SD (scan duration) commands. Starting a secure network, with AES encryption, also requires using the EE (encryption enable), KY (network key), LK (link key), and EO (encryption options) commands. See the Secure
Networks section later in this chapter for secure network considerations.
Starting an XBee Coordinator
To form a network, a coordinator must select an unused operating channel and PAN ID. The XBee modules support user-settable commands to control the process of selecting a channel and PAN
ID.
Table 4‐02. Commands that affect coordinator channel and PAN ID selection. See the command table for details.
Command Description
EI Used to specify the extended PAN ID. Setting EI to 0 allows a random extended PAN ID to be used.
SC
SD
EE
Selects a list of channels to scan for the energy and PAN scans.
Determines the duration of time to scan on each of the SC channels for the energy and PAN scans.
Determines if the coordinator should start a secure network using AES encryption.
If the coordinator has not already selected an operating PAN ID and channel, it performs an energy scan and PAN scan. The energy and PAN scans use the SC and SD values to determine the channels to scan, and how long to scan on each channel. The EI command is used to determine what extended PAN ID the coordinator should start on. An EI value of 0 allows the coordinator to start on a random extended PAN ID. The coordinator will select a random 16-bit PAN ID.
After completing the energy and PAN scans, the coordinator uses the results from the scans to select an operating channel and PAN ID for the network. If security is enabled (EE command), the coordinator will apply the security policy to the network. The coordinator startup process is outlined in the figure below.
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As soon as the XBee coordinator has formed the network on a PAN ID and channel, it:
• Allows joining for a time (NJ command)
• Starts blinking the Associate LED (D5, LT commands)
• Sends a Modem Status API frame ("coordinator started") out the UART (API firmware only).
The NJ parameter specifies the coordinator's permit-join time. (See section 3.3.1 - Allowing Joins for details.) The Associate LED will blink at a rate based on the LT command. The default rate
(LT=0) for a coordinator is 1 blink per second.
After the coordinator has successfully started, it behaves similar to a router - it can allow devices to join the network, and it can transmit, route, and receive data. The coordinator saves the selected channel and PAN ID settings into non-volatile memory so this information will persist through power cycles.
Example--Starting a Coordinator
1. Set SC and EI to the desired scan channels and PAN ID values. (The defaults should suffice.)
2. If SC or EI is changed from the default, issue the WR command to save the changes.
3. If SC or EI is changed from the default, apply changes (make SC and EI changes take effect) either by sending the AC command or by exiting AT command mode.
4. The Associate LED will start blinking once the coordinator has selected a channel and PAN ID.
5. The API Modem Status frame ("Coordinator Started") is sent out the UART (API firmware only).
6. Reading the AI command (association status) will return a value of 0, indicating a successful startup.
7. Reading the MY command (16-bit address) will return a value of 0, the ZigBee-defined 16-bit address of the coordinator
8. After startup, the coordinator will allow joining based on its NJ value.
Coming up from Reset
Once the coordinator has selected a PAN ID and channel, it retains that information throughpower cycle or reset events. When the coordinator comes up from a reset or power cycle, it checks its operating channel and PAN ID against the network configuration commands (SC and EI). It also verifies the applied security policy against the security configuration commands (EE, KY, LK). If the coordinator's operating channel, PAN ID, or security policy does not match the configuration commands, the coordinator will leave its current channel and PAN ID and attempt to form a new network based on its SC, EI, and EE parameter values. This is shown in the figure below.
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Note that if EI, SC, or EE change such that the last channel, security or PAN ID settings are no longer valid, the coordinator will go through the startup process again and could selecta different
PAN ID or channel. This is possible if EI, SC, or EE values are changed from theirdefaults and not saved (WR not issued), or if a command is issued to change EI, SC, or EE after the network has been formed.
Advanced Coordinator Startup Commands
In some cases, an application may wish to configure the initial 16-bit PAN ID. Under normal operating conditions, the 16-bit PAN ID should not be changed since the ZigBee-PRO stack can change it at anytime (if a conflict is detected). Forcing the initial 16-bit PAN ID is especially useful if one coordinator will be replaced with a new coordinator. The II command (initial PAN ID) can be used to force a new coordinator to come up on a fixed 16-bit PAN ID. The II command value is not saved through power cycle or reset.
Note: Due to advanced security in ZB, the II command cannot be used to install a replacement coordinator into a secure network.
The ZS command can be used (and written) to set the stack profile ID for the coordinator. The default ZS value (0) means the coordinator (and the entire XBee network) operates on a private network. If ZS is set to a non-zero value on the coordinator, all router and end devices that should join the coordinator must also have their ZS command parameter written to the same value.
The coordinator can be forced to leave its current channel or PAN ID by issuing the NR command.
Joining a ZB Router or End Device
Before a router or end device can participate in a ZigBee network, it must locate a nearby coordinator or another router that has already joined, and attempt to join to it. The commands listed in table 4-03 govern the joining behavior of routers and end devices.
Table 4‐03. Commands that affect router / end device PAN discovery during joining. See the command table for details.
Command
EI
Description
Used to specify the extended PAN ID. Setting EI to 0 allows the device to join any extended PAN
ID.
SC Selects a list of channels to scan for the energy and PAN scans.
SD
EE
Determines the duration of time to scan on each of the SC channels for the energy and PAN scans.
Determines the security policy of the joining device.
If a router or end device has not joined a network, it performs a PAN scan on each of the SC channels, looking for a coordinator or router operating on a valid PAN ID that is allowing joins. In order to successfully join a network, a new router or end device must find a device that meets the following requirements
• The extended PAN ID of the discovered device is valid based on the EI setting of the joining device.
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• The discovered device is allowing joins (NJ time has not expired)
• The discovered device is operating on one of the SC channels
• If the joining device is an end device, the discovered device has room for at least one more end device (NC command)
• The security policy of the discovered device is compatible with the security policy on the joining device (EE, LK, EO).
• The discovered device is operating on the same stack profile (ZS) as the joining device
If a device is discovered during the PAN scan that meets all the above requirements, the joining device will send a join request to the device and attempt to join the PAN. If the joining device receives a join response, then the device is considered joined to the PAN. The joining process is illustrated in the following figure.
Representation of the steps to join a ZigBee network
The status of the last PAN scan and join attempt is recorded into the AI command. When a router or end device successfully joins a network, AI is set to 0. Once an XBee router or end device has joined a network on a PAN ID and channel, it
• Allows joining for a time (NJ command, routers only)
• Start blinking the Associate LED (D5, LT commands)
• Sends a Modem Status API frame ("joined") out the UART (API firmware only)
• Sends a broadcast node identification transmission (JN)
The NJ parameter specifies the permit-join time on the router. (See chapter 3 for details on allowing joins.) The Associate LED will blink at a rate based on the LT command. The default rate
(LT=0) for a router or end device is 2 blinks per second. The broadcast join notification command is sent on a join event or power cycle event. This broadcast rapidly blinks the Associate LED on all recipients for 1 second. In addition, all recipients running API firmware send a Node Identification
API frame (0x95) out their UART. This behavior is useful for identifying which network a device has joined, but it is not recommended for large networks.
After a router or end device has successfully joined a network, it can transmit and receive data.
Routers can also route data and allow other devices to join the network. Routers and end devices save their channel and PAN ID settings into non-volatile memory so this information will persist through power cycles.
Example--Joining a PAN
1. Set SC and EI to the desired scan channels and PAN ID values. (The defaults should suffice.)
2. If SC or EI is changed from the default, issue the WR command to save the changes.
3. If SC or EI is changed from the default, apply changes (make SC and EI changes take effect) either by sending the AC command or by exiting AT command mode.
4. The Associate LED will start blinking once the router or end device has joined a PAN.
5. If the Associate LED is not blinking, the AI command can be read to determine the cause of join failure.
6. Once the router or end device has joined, the OE, OP, and CH commands will indicate the extended PAN ID, 16-bit PAN ID, and operating channel of the network it joined.
7. The MY command will reflect the 16-bit address that the device received when it joined.
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8. The MP command will reflect the 16-bit address of the end device's parent (end devices only).
9. The API Modem Status frame ("Joined") is sent out the UART (API firmware only).
10.A joined router will allow other devices to join for a time based on its NJ setting.
Coming up from Reset
Once the router or end device has joined on a PAN ID and channel, it retains that information through power cycle or reset events. When the router or end device comes up from a reset or power cycle, it checks its operating channel and PAN ID against the network configuration commands (SC and EI). It also verifies the applied security policy against the security configuration commands (EE, KY, LK). If the device's operating channel, PAN ID, or security policy does not match the configuration commands, it will leave its current channel and PAN ID and attempt to join a new network based on its SC, EI, and EE parameter values. This is shown in the figure below.
Note that if EI, SC, or EE change such that the last channel, security or PAN ID settings are no longer valid, the router or end device will go through the join process again and could potentially select a different PAN ID or channel. This is possible if EI, SC, or EE values are changed from their defaults and not saved (WR not issued), or if a command is issued to change
EI, SC, or EE after the device has joined a network.
A router or end device can be forced to leave its current channel or PAN ID by issuing the NR command.
Channel Verification
The ZB firmware supports channel verification behavior for both routers and end devices through the JV command. If channel verification is enabled, routers will communicate with the coordinator, and end devices will monitor their communications with their parent to determine if they are on a valid channel.
Router Channel Verification
When a router comes up from a power cycle, if JV=1, the router will send a 64-bit address discovery transmission to the coordinator to discover its 64-bit address. If the coordinator does not respond after 3 request attempts, the router will leave the current network and attempt to join a new network based on its SC, EI, and EE command values (see section 4.1.2).
If channel verification is enabled, the router will not consider itself joined until the coordinator response is received. This means the Associate LED will not blink, the modem status "Joined" frame will not be sent out the UART, and AI will not be set to 0 until after the coordinator response is received.
Router channel verification is not recommended for use in large networks.
End Device Channel Verification
If JV=1 on an end device, the end device tracks the status of its poll requests (communications) with its parent. If the end device's parent does not send an acknowledgment for 3 consecutive
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poll requests (3 consecutive no-acknowledgments), the end device will leave its current channel and PAN and attempt to join a network based on its SC, EI, and EE command values (see section
4.1.2).
Resetting Network Parameters
Once a coordinator has started or a router or end device has joined a network, the device will continue to operate on the same channel and PAN ID (even through power cycle or reset) until one of the following occurs:
• The PAN ID changes (EI command) such that the current operating PAN ID (EO) is invalid
• The scan channels mask changes (SC) such that the current operating channel is not valid
• One of the security parameters is changed (EE, EO, KY, LK)
• After a reset or power cycle with JV=1, a router does not receive a 64-bit address discovery response from the coordinator
• An end device with JV=1 does not receive poll acknowledgments from its parent for 3 consecutive polls.
• The NR1 or NR0 command is issued to force a device to leave.
If any of the above conditions occur on a coordinator, it will leave its current operating channel and PAN ID and attempt to start a new PAN as described in section 4.1.1. If any of the above conditions occur on a router or end device, it will leave its current operating channel and PAN ID and attempt to find a new PAN to join as described in section 4.1.2.
Note that with the exception of NR, any command parameter changes do not take effect until the changes are applied.
Secure Networks
If EE=1 on the coordinator, then it will apply a security policy to the network when it forms a network. Enabling security in a network adds an authentication step to the joining process. For example, after a router joins a network, it must then obtain the network security key to become authenticated. If the device cannot obtain the network security key, authentication fails, and the device leaves the network since it cannot communicate with anyone on the network.
The coordinator must decide the following:
• Whether or not to use a single trust center
• How the security keys (network and link keys) should be managed.
Using a Trust Center
A trust center is a single device that is responsible for determining who may join the network. If a trust center is enabled, the trust center must approve of each router or end device join that occurs on the network. If a router allows a new device to join the network, the router sends a notification to the trust center that a join has occurred. The trust center instructs the router to either authenticate the newly joined device or to force the device to leave. A trust center is required for some public ZigBee profiles.
To use a trust center in a ZigBee network, the coordinator should set the "use trust center" bit correctly in the EO command before starting a network.
Note: In the ZB firmware, only the coordinator can serve as the trust center.
Managing Security Keys
XBee defines a network key and a link key (trust center link key). Both keys are 128-bits and are used to apply AES encryption to RF packets. The network and link keys are write-only commands
- they can be written but not read.
The coordinator selects a network security key using the KY command. If KY is set to 0 (default), a random network key is chosen. Otherwise, the network key is set to the KY value. Similarly, the coordinator must also specify a link key using the LK command. If LK=0 (default), a random link key is selected.
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When a device joins a secure network, it must obtain the network key from the coordinator. The coordinator will either transmit the network key in the clear, or it can encrypt the network key using a pre-installed link key. If the EO option bit is set to transmit the network key unencrypted, or if the LK command value is set to 0 on the coordinator (select a random link key), the coordinator will transmit the network key in the clear, unencrypted. Otherwise, if the EO option bit is not set and LK > 0, the coordinator will encrypt the network key with the link key and transmit the network key encrypted to any joining devices.
If a joining device does not have the right preconfigured link key, and the network key is being sent encrypted, then the joining device will not be able to join the network.
Network Key Updates
As mentioned in chapter 3, network security requires a 32-bit frame counter be maintained by each device. This frame counter is incremented after each transmission and cannot wrap to 0. If a neighbor receives a transmission with a frame counter that is less than or equal to the last received frame counter, the packet will be discarded.
To prevent an eventual lockup where the frame counter on a device reaches 0xFFFFFFFF, the network key should be periodically updated (changed) on all devices in the network. To update the network key in the network, "the coordinator should issue the KY command with a new security key.. This will send a broadcast transmission throughout the network causing the frame counters on all devices to reset to 0, and causing devices to begin using the new network key. All devices will also retain the previous key for a short time until everyone has switched to the new key.
XBee ZB Addressing
XBee modules support both ZigBee device addressing and application-layer addressing. Device addressing provides a simple means of sending data from one device to another by hiding the application layer addressing information (ZigBee endpoints and cluster IDs). If a device will support multiple endpoints or cluster IDs, application addressing can be used to include endpoint and cluster ID information in the transmission.
Device addressing supports transmissions to:
• a destination 64-bit address
• a destination NI-string
• the ZigBee PAN coordinator
• all devices on the PAN (broadcast).
Application-layer addressing supports transmissions to:
• all of the above device addressing destinations
• specific endpoints on a destination device
• specific cluster IDs on a destination device.
Device Addressing
All XBee modules can be identified by their unique 64-bit addresses or a user-configurable ASCII string identifier The 64-bit address of a module can be read using the SH and SL commands. The
ASCII string identifier is configured using the NI command. To transmit using device addressing, only the destination address must be configured. The destination address can be specified using either the destination device’s 64-bit address or its NI-string. The XBee modules also support coordinator and broadcast addressing modes. Device addressing in the AT firmware is configured using the DL, DH, or DN commands. In the API firmware, the ZigBee Transmit Request API frame
(0x10) can be used to specify destination addresses.
Note: The Ember stack only delivers broadcast transmissions to end devices if the stack profile is set to 2. (See the ZS command.) This will be fixed in a future stack version.
64-Bit Addressing (Transparent)
To address a node by its 64-bit address, the destination address must be set to match the 64-bit address of the remote. In the AT firmware, the DH and DL commands set the destination 64-bit
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address. In the API firmware, the destination 64-bit address is set in the ZigBee Transmit Request frame.
To send a packet to an RF module using its 64-bit Address (Transparent Mode)
Set the DH (Destination Address High) and DL (Destination Address Low) parameters of the source node to match the 64-bit Address (SH (Serial Number High) and SL (Serial Number Low) parameters) of the destination node
Since the ZigBee protocol relies on the 16-bit network address for routing, the 64-bit address must be converted into a 16-bit network address prior to transmitting data. If a module does not know the 16-bit network address for a given 64-bit address, it will transmit a broadcast network address Discovery command. The module with a matching 64-bit address will transmit its 16-bit network address back. Once the network address is discovered, the data will be transmitted.
The modules maintain a small table to store some 64-bit addresses and their corresponding 16-bit addresses.
64-bit Addressing (API)
To send a packet to an RF module using its 64-bit Address (API Mode)
• Use the ZigBee Transmit Request API frame to set 64-bit destination address of the source node to match the 64-bit Address (SH (Serial Number High) and SL (Serial Number Low) parameters) of the destination node.
• If the 16-bit address of the destination node is not known, set 16-bit destination network address to 0xFFFE.
To send an API transmission to a Coordinator using its 16-bit network address:
• Set the 64-bit Destination Address field to all 0's.
API Mode provides the ability to store and maintain 16-bit network address tables on an external processor. The 16-bit network address information is provided to the application through the following:
• The ZigBee Transmit Status Frame
(contains the current 16-bit network address of the remote)
• The ND and DN commands
(return 64-bit and 16-bit network addresses of remote nodes)
With this information, a table can be built in an application that maps a 64-bit Address to the corresponding 16-bit network address.
The ZigBee Transmit Request API frame specifies the 64-bit Address and the network address (if known) that the packet should be sent to. By supplying both addresses, the module will forego network address Discovery and immediately attempt to route the data packet to the remote. If the network address of a particular remote changes, network address and route discovery will take place to establish a new route to the correct node. Upon successful packet delivery, the TX Status
Frame will indicate the correct network address of the remote.
Table 4‐04. Sample table mapping 64‐bit Addresses to 16‐bit Network Addresses
Index
2
3
0
1
64-bit Address
0013 A200 4000 0001
0013 A200 4000 0002
0013 A200 4000 01A0
0013 A200 4000 0220
16-bit Network Address
1234
5678
A479
FFFE (unknown)
NI-String Addressing
The NI string can alternatively be used to address a remote module.
To send a packet to an RF module using its NI-string (Transparent Mode)
Issue the DN (Destination Node) command using the NI (Node Identifier)-string of the destination node as the parameter.
To send a packet to an RF module using its NI-string (API Mode)
Issue the DN command as stated above using the AT Command API frame.
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When the DN command is issued, a broadcast transmission is sent across the network to discover the module that has a matching NI (Node Identifier) parameter. If a module is discovered with a matching NI-string, the DH and DL parameters will be configured to address the destination node and the command will return both the 64-bit Address and the 16-bit network address of the discovered node. Data can be transmitted after the DN (Destination Node) command finishes.
Note that issuing DN sends a broadcast transmission into the network. This addressing method should be used sparingly
Coordinator Addressing
A Coordinator can be addressed using its 64-bit address or NI string as described in the “NI-String
Addressing” section. Alternatively, since the ZigBee Coordinator has a network address of “0”, it can be addressed by its 16-bit network address.
To send a transmission to a Coordinator using its 16-bit network address:
Set the Destination Address of the transmitting module as shown below:
AT Firmware
DL (Destination Low Address) = 0
DH (Destination High Address) = 0
API Firmware
Set the 64-bit destination address field in the API transmit frame to
0x0000000000000000.
Broadcast Addressing
Broadcast transmissions are sent using a 64-bit address of 0x0000FFFF. Any RF module in the PAN will accept a packet that contains a broadcast address. When configured to operate in Broadcast
Mode, receiving modules do not send ACKs (Acknowledgements).
To send a broadcast packet to all modules
Set the Destination Addresses of the transmitting module as shown below:
AT Firmware
DL (Destination Low Address) = 0x0000FFFF
DH (Destination High Address) = 0x00000000
API Firmware
Set the 64-bit destination address field in the API transmit frame to 0x000000000000FFFF.
Since broadcast transmissions are repeated by all devices in the network, broadcasts should be used sparingly
Application-layer Addressing
Application-layer addressing allows the application to specify endpoint and cluster ID values for each transmission. Addressing multiple endpoints and cluster IDs can be accomplished by explicitly setting these values as needed.
In AT firmware, application-layer addressing must be enabled using the ZA command. When application-layer addressing is enabled, the DE and SE commands specify the source and destination endpoints, and the CI command sets the cluster ID that will be used in the transmission.
In API firmware, the Explicit Addressing ZigBee Command frame (0x11) can be used to configure the endpoint and cluster ID addressing parameters as needed. The destination device can indicate application-layer addressing information depending on the AO parameter. Some endpoint values are reserved for use by the XBee modules and should not be used. Please refer to the following tables for these values:The following cluster IDs are supported on the data endpoint (0xE8):
Table 4‐05. XBee Endpoint allocation
Endpoint
0
Description
ZigBee Device Objects endpoint. Reserved for ZigBee stack.
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Table 4‐05. XBee Endpoint allocation
Endpoint
0x01 - 0xDB (219)
0xDC (220) - 0xEE
(238)
0xE6 (230)
0xE8 (232)
0xEF (239) - 0xF0 (240)
Description
Available endpoints
Reserved for Digi Use
Command Endpoint
Data Endpoint
Reserved for Ember Use
Table 4‐06. Supported Cluster IDs on the Data Endpoint
Cluster ID
0x11
0x12
0x92
0x94
0x95
Name
Transparent serial data
Serial loopback data
IO sample data
XBee sensor sample data
Node identification
Description
This is the default cluster ID used to transmit serial data.
Data received on this cluster ID is transmitted back to the sender.
IO samples are transmitted to a remote on this cluster ID.
An XBee sensor device transmits sensor readings on this cluster ID.
A single press on the commissioning button sends a broadcast transmission to this cluster ID.
ZigBee Device Objects
ZigBee reserved endpoint 0 for ZigBee Device Objects (ZDO). This endpoint supports many discovery and management services. Each ZDO service has a unique cluster ID. Some of the more common ZDO services and their cluster IDs are listed below:
The Explicit API frame (0x11) can be used to send ZDO commands to a remote device. To send a
ZDO command, the source and destination endpoints should be set to 0, the profile ID should be set to 0x0000, and the cluster ID should be set to the value that corresponds to the ZDO command being sent. The data payload field should be populated with a 1-byte sequence number, followed by the required data for the ZDO command. All multi-byte values should be sent using little-endian format.
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To receive API ZDO response frames, the AO command must be set to enable the Explicit Rx API frame (0x91). All ZDO command responses are received on endpoint 0 and profile ID 0x0000. All multi-byte values in the API ZDO responses are sent in little endian byte order.
Example: Send an LQI Request using the explicit API frame to obtain the neighbor table from a remote (64-bit address = 0x0013A200 404A210C). (For the ZDO LQI response to be received, AO must be set to enable the Explicit Rx Indicator API frame. See the command table for details.)
Send the API frame:
0x7E 00 16 11 01 00 13 A2 00 40 4A 21 0C FF FE 00 00 00 31 00 00 00 00 32 00 21 where:
0x0016 - API fame length
0x11 - Explicit API transmit frame
0x01 - Frame ID (arbitrarily chosen value)
0x0013A200 404A210C - 64-bit destination address
0xFFFE - 16-bit destination address (unknown)
0x00, 0x00 - Source and destination endpoints (ZDO)
0x0031 - LQI Request Cluster ID
0x0000 - ZigBee Device Profile ID
0x00 - Broadcast radius
0x00 - Transmit options
Data payload:
0x32 - Transaction sequence number (arbitrarily selected)
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0x00 - Neighbor Table start index (required field for LQI request command)
0x21 - Checksum
See the ZigBee specification for ZDO formatting details.
Maximum RF Data Payloads
The maximum RF data payload depends on the type of transmission and whether or not security is enabled. The maximum data payload sizes are shown in the table below:
Transmission Type Maximum RF Data Payload (bytes)
Broadcast, no security
Unicast, no security
Broadcast, security
Unicast, security
92
84
74
66
Sleeping End Devices
XBee modules support sleep mode operation in the Router / End Device firmware. Sleep modes allow a ZigBee end device to enter a low power mode when idle and wake as needed to transmit or receive data.
End devices must join to a router or coordinator to become part of a network. When the join occurs, the end device becomes the child of the router or coordinator that allowed the join, and the device that allowed the join becomes the end device’s parent.
A router or coordinator can only allow up to 8 end devices to join to it. Once 8 end devices have joined to a parent, no additional end devices can join until a network reset condition occurs on the parent.
End Device Operation
ZigBee end devices rely on a parent (router or coordinator) to remain awake and receive any data packets destined for the end device. When the end device wakes from sleep, it sends a transmission (poll request) to its parent asking if the parent has received any RF data destined for the end device. The parent, upon receipt of the poll request, will send an RF response and the buffered data (if present).
If the parent has no data for the end device, the end device may return to sleep, depending on its sleep mode configuration settings. The following figure demonstrates how the end device uses polling to receive RF data through its parent.
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If the end device is awake with the ST timer running (SM=4), or if Sleep_RQ is de-asserted
(SM=1), the end device will send poll requests every 100ms to ensure it receives any new RF data from its parent.
Figure 4‐011.RF Data Sent to Sleeping End Device
D e vice in a M e s h
N e tw o rk
S o u rce
T X
P a re n t
P o ll
D a ta
P o ll
C h ild
(sle e pin g en d d e vice )
D e stina tio n
W h e n R F d ata is s e n t to a slee p in g en d d e v ic e , th e e n d d e v ic e’s p are n ts b u ffers th e d ata u n til th e e n d d e v ic e p o lls fo r th e d ata , o r a tim eo u t o c cu rs
Parent Operation
When an end device joins a ZigBee PAN, it becomes a child of the (coordinator or router) device it joined to, and the device that allowed the join becomes the end device's parent. Thereafter, the parent will manage RF data packets for the end device. If the parent receives an RF packet destined for the end device, it will store the data packet until one of the following occurs:
• The parent runs out of storage space and cannot store a new packet.
• A packet has been stored for a period of time (timeout).
• The destination end device child sends a poll request transmission to request the data packet.
When the parent stores a packet destined for an end device child, it stores the packet for a maximum time set by SP. The actual storage time is computed as (SP * 2.5), not exceeding 30 seconds. If end devices implement cyclic sleep, SP should be set the same on a parent as it is on their sleeping end device children. In the case of pin sleep, where RF data could be received, the end device should wake within SP time to ensure incoming RF data is not lost. The parent can only store one broadcast packet (the most recently received) for its end device children.
The parent is also responsible for performing any route or address discoveries to forward data sent by its end device child(ren) into the mesh network. The parent’s interactions with the mesh network in behalf of its end device child(ren) are shown in the figure below. (Note address and route discoveries occur only as needed.)
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Figure 4‐012.Determining the End Device Route
Device in mesh network
Network Address Request
Network Address Response
Route Request
Route Reply
Data (end device)
Parent Child
(sleeping end device)
Source Destination
To talk to an end device, a source device in a mesh network must talk to the parent to determine the address and the route of the end device. The source device then sends data to the parent.
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Device in mesh network
Figure 4‐013.End Device: Sending Data to Parente
Network Address Request
Network Address Response
Route Request
Parent
Route Reply
Data
Destination
Data
An end device sends data to its parent to route to the correct destination node. The parent performs all of the necessary addressing and route discoveries before forwarding the data.
Child
(sleeping end device)
Source
End Device Behavior
An end device child retrieves RF data from its parent through polling. When the end device wakes from sleep, it sends a poll request to its parent, notifying the parent that it is awake, and requesting any data the parent has received that was addressed to the end device child. If the parent has data for the end device, the end device will continue polling.
Parent Behavior
The parent of an end device remains awake and can receive data packets intended for any of its end device children. Since the end device child may be sleeping, the parent buffers any received
RF data that is destined for an end device child until the end device asks for it, or until a timeout occurs. This timeout is settable using the SP command. The actual timeout is calculated as (2.5 *
SP), not exceeding 30 seconds.
End Device Sleep Configuration
Configuration parameters exist to customize the mechanisms for entering sleep and defining sleep and wake times. The XBee modules support both pin sleep and cyclic sleep modes. The sleep mode is settable using the SM command. If SM=0, sleep mode is disabled and the device operates as a router. If SM changes from 0 to a non-zero value, the router leaves the ZigBee network and attempts to rejoin as an end device. For this change to be successful, the end device must be able to join a nearby router or coordinator that is allowing end device joins. (See [Add
Reference Here] for details.)
The On/Sleep pin (pin 13) provides a hardware indication of whether the module is asleep or not.
On/Sleep is de-asserted (low) when the module enters sleep and asserted (high) when the module wakes.
If CTS flow control is disabled (D7 command), the CTS pin is also de-asserted (high) when entering sleep, and asserted (low) upon waking.
Pin Sleep
Pin sleep puts the module to sleep and wakes it from sleep according to the state of Sleep_RQ (pin
9). Pin sleep is enabled by setting SM to 1.
When Sleep_RQ is asserted (high), the module will finish any transmit or receive operations, and then enter a low power state. If the module has not joined a network and Sleep_RQ is asserted,
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the module will sleep once the current join attempt completes (ie scanning for a valid network to join). While asleep, the module will not respond to serial or RF activity.
To wake a module operating in pin sleep, de-assert Sleep_RQ (pin 9). The module will wake when
Sleep_RQ is de-asserted and is ready to transmit or receive when the CTS line is low. If the module has not joined a network, it will scan for a network to join when it wakes.
When a joined end device wakes from pin sleep, it sends a poll request to its parent to see if the parent has buffered data for the end device. The end device will continue to send poll requests every 100ms while it remains awake.
Figure 4‐014.Demonstration of Pin Sleep
Sleep_RQ
(pin 9)
Vcc
0V
Demonstration of a pin sleep end device that sends poll requests to its parent when awake
Legend
Sleep_RQ
Transmitting Poll
Request
Cyclic Sleep
Cyclic sleep allows modules to wake periodically to check for RF data and sleep when idle. When the SM parameter is set to 4 or 5, the module operates in cyclic sleep mode. Setting SM to 5 allows the module to be awakened from sleep on a high-to-low transition on Sleep_RQ (pin 9).
Setting SM to 4 disables the pin wake option.
In cyclic sleep mode, if serial or RF data is received, the module will start an inactivity timer and remain awake until this timer expires. The inactivity time is settable with the ST command. While the module is awake, it will continue to send poll request transmissions to its parent to check for buffered data every 100ms. The timer will be restarted anytime serial or RF data is received. The module will resume sleep when the timer expires. This behavior is shown in the following figure.
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Figure 4‐015.Cylic Sleep
DIN
ST = Time Awake
On/Sleep
A cyclic sleep end device enters sleep mode when no serial or RF data is received for ST time.
Legend
On/Sleep
Transmitting Poll
Request
In cyclic sleep, the time the module sleeps for is dependent on several configuration commands –
SP, SN, and SO.
With SO set to 0 (no sleep options - default), the sleep period is defined as (SP * SN). Since the parent can only buffer data up to 30 seconds, SP is settable up to 28 seconds. After SP expires, the module wakes to send a poll request transmission to the parent to check for data. This helps ensure the end device can receive RF data transmissions that were sent to it.
In many cases, the On/Sleep pin can be used to wake an external microprocessor or peripheral device when the module wakes from sleep. If the end device wakes and finds that its parent had no data, there may be no need to wake the external device. The SN command is a multiplier of the SP time that determines how often to set the On/Sleep pin when waking. For example, if the end device sleeps for 20 seconds, but the On/Sleep pin should only be set high on every 3rd poll
(once per minute), SN can be set to 3. The On/Sleep pin will be set high anytime RF data is received, regardless of SN. This is shown in the figure below.
In some applications, the end device may transmit data at a very slow rate (once an hour, once a day, etc) and will only receive data in response to its transmission. In such cases, the SO command can be used to cause an end device to sleep for the entire SP * SN duration. This is shown below.
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Figure 4‐016.Polling for Data without Asserting On/Sleep
On/Sleep
(SN = 1)
? t = SP * SN
On/Sleep
(SN = 3)
? t = SP * SN
Transmitting poll request to parent
? t = SP
Transmitting poll request to parent
? t = SP
Setting SN > 1 allows the XBee to silently poll for data without asserting On/Sleep. If RF data is received when polling, On/Sleep will immediately assert.
Legend
Sleep_RQ
Transmitting Poll
Request
Figure 4‐017.Transmitting Poll Request to Parent
O n /S le e p ( S O = 4 )
? t = S P * S N
T ra n s m ittin g P o ll R e q u e s t to P a re n t (S O = 4 )
? t = S P * S N
S e ttin g S O = 4 w ill c a u s e th e e n d d e v ic e to s le e p fo r th e e n tir e S P * S N tim e . T h is s h o u ld o n ly b e u s e d if th e e n d d e v ic e w ill n o t r e c e iv e R F d a ta w h ile s le e p in g .
Since a parent can only buffer data up to 30 seconds, an end device should only sleep for more than 30 seconds if it will not receive RF data when sleeping. The ST parameter can be set to keep the end device awake after transmitting data to receive RF data. The commissioning push button can be used to force the end device to wake for 30 seconds. See section 6.4 for details.
Transmitting Data to End Devices
To reliably transmit data to an end device, SP should be set the same on the end device, the end device’s parent, and on the device that is initiating a transmission to the end device. SP determines the transmission timeout on the sender, the time to buffer the received packet on the parent, and the time to sleep on the end device.
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Remote Configuration Commands
The API firmware has provisions to send configuration commands to remote devices using the
Remote Command Request API frame (see Chapter 7 – API Operation). This API frame can be used to send commands to a remote module to read or set command parameters.
The API firmware has provisions to send configuration commands (set or read) to a remote module using the Remote Command Request API frame (see chapter 8). Remote commands can be issued to read or set command parameters on a remote device.
Sending a Remote Command
To send a remote command, the Remote Command Request frame should be populated with the
64-bit address and the 16-bit address (if known) of the remote device, the correct command options value, and the command and parameter data (optional). If a command response is desired, the Frame ID should be set to a non-zero value.
Applying Changes on Remote Devices
When remote commands are used to change command parameter settings on a remote device, parameter changes do not take effect until the changes are applied. For example, changing the
BD parameter will not change the actual serial interface rate on the remote until the changes are applied. Changes can be applied using remote commands in one of three ways:
• Set the apply changes option bit in the API frame
• Issue an AC command to the remote device
• Issue a WR + FR command to the remote device to save changes and reset the device.
Remote Command Responses
If the remote device receives a remote command request transmission, and the API frame ID is non-zero, the remote will send a remote command response transmission back to the device that sent the remote command. When a remote command response transmission is received, a device sends a remote command response API frame out its UART. The remote command response indicates the status of the command (success, or reason for failure), and in the case of a command query, it will include the register value.
The device that sends a remote command will not receive a remote command response frame if:
• The destination device could not be reached
• The frame ID in the remote command request is set to 0.
IO Line Monitoring
XBee modules support analog inputs and digital IO. Analog and digital IO can be set or read. The
XBee supports the following IO functions:
Table 4‐07.
Module Pin Names Module Pin Numbers Configuration Command
CD/DIO12 4 P2
PWM0/RSSIM/DIO10
PWM/DIO11
6
7
P0
P1
SLEEP_RQ/DIO8
DIO4
CTS/DIO7
ON_SLEEP/DIO9
9
11
12
13
IO Configuration not supported
D4
D7
IO Configuration not supported
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4
5
6-9
2
3
0
1
Table 4‐07.
Module Pin Names Module Pin Numbers Configuration Command
ASSOC/DIO5 15 D5
RTS/DIO6
AD3/DIO3
16
17
D6
D3
AD2/DIO2
AD1/DIO1
18
19
D2
DI
AD0/DIO0 20 D0
Setting the configuration command that corresponds to a particular pin will configure the pin. IO line command settings include the following:
Table 4‐08.
Pin Command Parameter Description
Unmonitored digital input
Reserved for pin-specific alternate functionalities
Analog input, single ended (A/D pins only)
Digital input, monitored
Digital output, default low
Digital output, default high
Alternate functionalities, where applicable
For example, sending the command “ATD23” will configure AD2/DIO2 (pin 18) as a digital input.
Pullup resistors can be set for each digital input using the PR command.
IO Samples
When an IO sample is taken, the collected data is assembled into a packet and either sent out the uart or transmitted to a remote device. The IO sample is formatted in the following manner:
Table 4‐09.
Bytes Name Description
1 Sample Sets Number of sample sets in the packet. (Always set to 1.)
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Table 4‐09.
2
Bytes Name
Digital Channel Mask
Description
Indicates which digital IO lines have sampling enabled. Each bit corresponds to one digital IO line on the module.
• bit 0 = AD0/DIO0
• bit 1 = AD1/DIO1
• bit 2 = AD2/DIO2
• bit 3 = AD3/DIO3
• bit 4 = DIO4
• bit 5 = ASSOC/DIO5
• bit 6 = RTS/DIO6
• bit 7 = CTS/GPIO7
• bit 8 = N/A
• bit 9 = N/A
• bit 10 = RSSI/DIO10
• bit 11 = PWM/DIO11
• bit 12 = CD/DIO12
For example, a digital channel mask of 0x002F means DIO0,1,2,3, and 5 are enabled as digital IO.
Indicates which lines have analog inputs enabled for sampling. Each bit in the analog channel mask corresponds to one analog input channel.
• bit 0 = AD0/DIO0
1 Analog Channel Mask
• bit 1 = AD1/DIO1
• bit 2 = AD2/DIO2
Variable Sampled Data Set
• bit 3 = AD3/DIO3
• bit 7 = Supply Voltage
A sample set consisting of 1 sample for each enabled ADC and/or DIO channel, which has voltage inputs of 1143.75 and 342.1875mV.
If any digital IO lines are enabled, the first two bytes of the data set indicate the state of all enabled digital IO. Only digital channels that are enabled in the Digital Channel
Mask bytes have any meaning in the sample set. If no digital IO are enabled on the device, these 2 bytes will be omitted.
Following the digital IO data (if any), each enabled analog channel will return 2 bytes.
The data starts with AIN0 and continues sequentially for each enabled analog input channel up to AIN3, and the supply voltage (if enabled) at the end.
The sampled data set will include 2 bytes of digital IO data only if one or more IO lines on the device are configured as digital IO. If no pins are configured as digital IO, these 2 bytes will be omitted.
The digital IO data is only relevant if the same bit is enabled in the digital IO mask as shown in the following figure:
Analog samples are returned as 10-bit values. The analog reading is scaled such that 0x0000 represents 0V, and 0x3FF = 1.2V. (The analog inputs on the module cannot read more than
1.2V.) Analog samples are returned in order starting with AIN0 and finishing with AIN3, and the supply voltage. Only enabled analog input channels return data as shown in the figure below.
To convert the A/D reading to mV, do the following:
AD(mV) = (A/D reading * 1200mV) / 1024
TThe reading in the sample frame represents voltage inputs of 1143.75 and 342.1875mV for AD0 and AD1 respectively.
Queried Sampling
The IS command can be sent to a device locally, or to a remote device using the API remote command frame (see Chapter 8 for details). When the IS command is sent, the receiving device
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samples all enabled digital IO and analog input channels and returns an IO sample. If IS is sent locally, the IO sample is sent out the uart. If the IS command was received as a remote command, the IO sample is sent over-the-air to the device that sent the IS command.
If the IS command is issued in AT firmware, the module returns a carriage return-delimited list containing the above-listed fields. The API firmware returns an AT command response packet with the IO data included in the command data portion of the response frame.
The following table shows an example of the fields in an IS reponse.
.
Table 4‐010.
Example
0x01
0x0C0C
0x03
0x0408
0x03D0
0x0124
Sample AT Response
[1 sample set]
[Digital Inputs: DIO 2, 3, 10, 11 low]
[Analog Inputs: A/D 0, 1]
[Digital input states: DIO 3, 10 high, DIO 2, 11 low]
[Analog input ADIO 0= 0x3D0]
[Analog input ADIO 1=0x120]
Periodic IO Sampling
Periodic sampling allows an XBee / XBee-PRO module to take an IO sample and transmit it to a remote device at a periodic rate. The periodic sample rate is set by the IR command. If IR is set to 0, periodic sampling is disabled. For all other values of IR, data will be sampled after IR milliseconds have elapsed and transmitted to a remote device. The DH and DL commands determine the destination address of the IO samples. DH and DL can be set to 0 to transmit to the coordinator, or to the 64-bit address of the remote device (SH and SL). Only devices running API firmware can send IO data samples out their Uart. Devices running AT firmware will discard received IO data samples.
A sleepy end device will transmit periodic IO samples at the IR rate until the ST timer expires and the device can resume sleeping. See section 5.3 for more information on sleep.
Digital IO Change Detection
Modules can be configured to transmit a data sample immediately whenever a monitored digital IO pin changes state. The IC command is a bitmask that can be used to set which digital IO lines should be monitored for a state change. If one or more bits in IC is set, an IO sample will be transmitted as soon as a state change is observed in one of the monitored digital IO lines. Figure xx below shows how edge detection can work with periodic sampling.
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Figure 4‐018.Enabling Edge Detection
Monitored Digital
IO Line
IO Sample Transmissions
(IR > 0, IC = 0)
?t = IR
IO Sample Transmissions
(IR > 0, IC > 0)
?t = IR
Enabling Edge Detection will force an immediate sample of all monitored digital IO lines if any digital IO lines change state.
Voltage Supply Monitoring
The voltage supply threshold is set with the V+ command. If the measured supply voltage falls below or equal to this threshold, the supply voltage will be included in the IO sample set. V+ is set to 0 by default (do not include the supply voltage).
I/O Line Configuration
The XBee modules support both analog input and digital IO line modes on several configurable pins.
Configuring A/D and Digital Lines
The following table lists the pin functions supported on the modules
.
Table 4‐011.
Module Pin Names Module Pin Numbers Configuration Command
CD/DIO12 4 P2
PWM0/RSSI/DIO10
PWM/DIO11
6
7
P0
P1
SLEEP_RQ/DIO8
DIO4
CTS/DIO7
ON_SLEEP/DIO9
9
11
12
13
IO Configuration not supported
D4
D7
IO Configuration not supported
ASSOC/DIO5
RTS/DIO6
AD3/DIO3
AD2/DIO2
17
18
15
16
D5
D6
D3
D2
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4
5
6-9
2
3
0
1
Table 4‐011.
Module Pin Names Module Pin Numbers Configuration Command
AD1/DIO1 19 DI
AD0/DIO0 20 D0
Setting the configuration command that corresponds to a particular pin will configure the pin.
Parameters for the pin configuration commands typically include the following:
.
Table 4‐012.
Pin Command Parameter Description
Unmonitored digital input
Reserved for pin-specific alternate functionalities
Analog input, single ended (A/D pins only)
Digital input, monitored
Digital output, default low
Digital output, default high
Alternate functionalities, where applicable
See the command table for more information. Pullup resistors for each digital input can be enabled using the PR command.
Sampling A/D and Digital Input Lines
The IS command can be used to sample the current value of all enabled A/D and digital input lines. .
Table 4‐013.
Bytes
1
2
1
Name
Sample sets in packet
Digital Channel Mask
Analog Channel Mask
Description
Number of sample sets in the packet
Each bit in the digital channel mask corresponds to one digital IO line. The bits, from LSB to MSB, correspond to DOI0-DOI5 on the module.
For example a digital channel mask of 0x002F means DIO0,1,2,3, and 5 are enabled as digital input lines.
Each bit in the analog channel mask corresponds to one analog channel. The bits from LSB to MSB correspond to AIN0-AIN7 on the module.
For example, if the analog channel mask is 0x06, AINI and AIN3 are enabled as analog input lines.
Var Sampled Data Set
A sample set consisting of 1 sample for each enabled ADC and/or DIO channel. If any digital input lines are enabled, the first two bytes indicate the state of all enabled digital input lines. Each bit in these two bytes corresponds to one digital IO line, similar to the way each bit in the diglossia channel mask corresponds. Note: only the digital input line that are enabled in the detail channel mask have valid readings. Channels that are not enabled as digital input lines will return a 0 in the sampled data set. If no pins are configured as digital inputs, these 2 bytes will be omitted.
Following the digital input data, if any, each enabled analog channel will return
2 bytes (10bits). The analog data is scaled such that 0 represents 0V, and
0x3FF=1.2V. The analog input lines cannot measure more than 1.2V.
Information for each enabled analog channel is returned in order, starting with
AIN0 and finishing with AIN4. Only enabled analog input channels will return data.
The AT firmware returns a carriage return delimited list containing the above-listed fields. The API firmware returns an AT command response API frame with the IO data included in the command data portion of the packet.
Table 4‐014.
Example Sample AT Response
0x01\r [1 sample set]
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Table 4‐014.
Example
0x0C0C\r
0x03\r
0x0408\r
0x03D0\r
0x0124\r
Sample AT Response
[Digital Inputs: DIO 2, 3, 10, 11 low]
[Analog Inputs: A/D 0, 1]
[Digital input states: DIO 3, 10 high, DIO 2, 11 low]
[Analog input ADIO 0= 0x3D0]
[Analog input ADIO 1=0x120]
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5. Network Commissioning and Diagnostics
Network commissioning is the process whereby devices in a mesh network are discovered and configured for operation. The XBee modules include several features to support device discovery and configuration. In addition to configuring devices, a strategy must be developed to place devices to ensure reliable routes.
To accommodate these requirements, the XBee modules include various features to aid in device placement, configuration, and network diagnostics.
Device Discovery
The node discovery command can be used to discover all modules that have joined a network.
Issuing the ND command sends a broadcast node discovery command throughout the network.
All devices that receive the command will send a response that includes the device’s addressing information, node identifier string (see NI command), and other relevant information. This command is useful for generating a list of all module addresses in a network.
When a device receives the node discovery command, it waits a random time before sending its own response. The maximum time delay is set on the ND sender with the NT command. The ND originator includes its NT setting in the transmission to provide a delay window for all devices in the network. Large networks may need to increase NT to improve network discovery reliability.
The default NT value is 0x3C (6 seconds).
Device Configuration
API devices can send configuration commands to remote modules to set or read the configuration settings of any device in the network.
Device Placement
For a mesh network installation to be successful, the installer must be able to determine where to place individual XBee devices to establish reliable links throughout the mesh network.
Link Testing
A good way to measure the performance of a mesh network is to send unicast data through the network from one device to another to determine the success rate of many transmissions. To simplify link testing, the modules support a loopback cluster ID (0x12) on the data endpoint
(0xE8). Any data sent to this cluster ID on the data endpoint will be transmitted back to the sender. This is shown in the figure below:
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Source Device
Figure 5‐019.Link Quality in a Mesh Network
Mesh Network
1
Transmit data to the loopback cluster ID
(0x12) and data endpoint (0xE8) on a remote device
4
Source receives loopback transmission and sends received data packet out the
UART
2
The remote device receives data on the loopback cluster ID and data endpoint
Remote Device
3
Remote transmits the received packet back to the sender
Demonstration of how the loopback cluster ID and data endpoint can be used to measure the link quality in a mesh network
The configuration steps to send data to the loopback cluster ID depend on the firmware type.
AT Firmware
To send data to the loopback cluster ID on the data endpoint of a remote device, set the ZA command to 1 and set the CI command value to 0x12. The SE and DE commands should be set to
0xE8 (default value). The DH and DL commands should be set to the address of the remote (0 for the coordinator, or the 64-bit address of the remote). After exiting command mode, any received serial characters will be transmitted to the remote device, and returned to the sender.
API Firmware
Send an Explicit Addressing ZigBee Command API frame (0x11) using 0x12 as the cluster ID and
0xE8 as the source and destination endpoint. Data packets received by the remote will be echoed back to the sender.
RSSI Indicators
It is possible to measure the received signal strength on a device using the DB command. DB returns the RSSI value (measured in –dBm) of the last received packet. However, this number can be misleading. The DB value only indicates the received signal strength of the last hop. If a transmission spans multiple hops, the DB value provides no indication of the overall transmission path, or the quality of the worst link – it only indicates the quality of the last link and should be used sparingly.
The DB value can be determined in hardware using the RSSI/PWM module pin (pin 6). If the RSSI
PWM functionality is enabled (P0 command), when the module receives data, the RSSI PWM is set to a value based on the RSSI of the received packet. (Again, this value only indicates the quality of the last hop.) This pin could potentially be connected to an LED to indicate if the link is stable or not.
Commissioning Pushbutton and Associate LED
The XBee modules support a set of commissioning and LED behaviors to aid in device deployment and commissioning. These include the commissioning push button definitions and associate LED behaviors. These features can be supported in hardware as shown below.
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Figure 5‐020. Commissioning Pushbutton and Associate LED Functionalities
Push button
20
XBee
15
R
Associate
LED
A pushbutton and an LED can be connected to module pins 20 and 15 respectively to support the commissioning pushbutton and associate LED functionalities.
Commissioning Pushbutton
The commissioning pushbutton definitions provide a variety of simple functions to aid in deploying devices in a network. The commissioning button functionality on pin 20 is enabled by setting the
D0 command to 1 (enabled by default)..
Table 5‐015.
Button
Presses
If module is joined to a network
If module is not joined to a network
1
• Wakes an end device for
30 seconds
• Sends a node identification broadcast transmission
• Wakes an end device for
30 seconds
• Blinks a numeric error code on the Associate pin indicating the cause of join failure (see section
6.4.2).
2
4
• Sends a broadcast transmission to enable joining on the coordinator and all devices in the network for
1 minute. (If joining is permanently enabled on a device (NJ = 0xFF), this action has no effect on that device.)
• Causes the device to leave the PAN.
• Issues ATRE to restore module parameters to default values, including
ID and SC.
• The device attempts to join a network based on its ID and SC settings.
• N/A
• Issues ATRE to restore module parameters to default values, including
ID and SC.
• The device attempts to join a network based on its ID and SC settings.
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Button presses may be simulated in software using the ATCB command. ATCB should be issued with a parameter set to the number of button presses to execute. (i.e. sending ATCB1 will execute the action(s) associated with a single button press.)
The node identification frame is similar to the node discovery response frame – it contains the device’s address, node identifier string (NI command), and other relevant data. All API devices that receive the node identification frame send it out their Uart as an API Node Identification
Indicator frame (0x95).
Associate LED
The Associate pin (pin 15) can provide indication of the device’s network status and diagnostics information. To take advantage of these indications, an LED can be connected to the Associate pin as shown in the figure above. The Associate LED functionality is enabled by setting the D5 command to 1 (enabled by default). If enabled, the Associate pin is configured as an output and will behave as described in the following sections.
Joined Indication
The Associate pin indicates the network status of a device. If the module is not joined to a network, the Associate pin is set high. Once the module successfully joins a network, the
Associate pin blinks at a regular time interval. This is shown in the following figure.
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Associate
Figure 5‐021.Joined Status of a Device
Device Not Joined
Δt
Device has joined a network
The associate pin can indicate the joined status of a device . Once the device has joined a network, the associate pin toggles state at a regular interval (Δt). The time can be set by using the LT command.
The LT command defines the blink time of the Associate pin. If set to 0, the device uses the default blink time (500ms for coordinator, 250ms for routers and end devices).
Diagnostics Support
The Associate pin works with the commissioning pushbutton to provide additional diagnostics behaviors to aid in deploying and testing a network. If the commissioning push button is pressed once, and the device has not joined a network, the Associate pin blinks a numeric error code to indicate the cause of join failure. The number of blinks is equal to (AI value – 0x20). For example, if AI=0x22, 2 blinks occur.
If the commissioning push button is pressed once, and the device has joined a network, the device transmits a broadcast node identification packet. If the Associate LED functionality is enabled (D5 command), a device that receive this transmission will blink its Associate pin rapidly for 1 second.
The following figures demonstrate these behaviors.
Figure 5‐022. AI = 0x22
Associate
(D5 = 1
Device not joined)
AD0/DIO0
A single commissioning button press when the device has not joined a network tha causes the associate pin to blink to indicate the AI Code where: AI = # blinks + 0x20
In this example, AI = 0x22.
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Associate Pin
(D5 = 1)
Figure 5‐023. Broadcast Node Identification Transmission
AD0/DIO0 Pin
(Remote Device)
A single button press on a remote device causes a broadcast node identification transmission to be sent. All devices that receive this transmission blink their associate pin rapidly for one second if the associate LED functionality is enabled. (D5 = 1)
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6. API Operation
As an alternative to Transparent Operation, API (Application Programming Interface) Operations are available. API operation requires that communication with the module be done through a structured interface (data is communicated in frames in a defined order). The API specifies how commands, command responses and module status messages are sent and received from the module using a UART Data Frame.
Please note that Digi may add new API frames to future versions of firmware, so please build into your software interface the ability to filter out additional API frames with unknown API identifiers.
API Frame Specifications
Two API modes are supported and both can be enabled using the AP (API Enable) command. Use the following AP parameter values to configure the module to operate in a particular mode:
• AP = 1: API Operation
• AP = 2: API Operation (with escaped characters)
API Operation (AP parameter = 1)
When this API mode is enabled (AP = 1), the UART data frame structure is defined as follows:
Figure 6‐01. UART Data Frame Structure:
Start Delimiter
(Byte 1)
0x7E
Length
(Bytes 2-3)
MSB LSB
Frame Data
(Bytes 4-n)
API-specific Structure
Checksum
(Byte n + 1)
1 Byte
MSB = Most Significant Byte, LSB = Least Significant Byte
Any data received prior to the start delimiter is silently discarded. If the frame is not received correctly or if the checksum fails, the module will reply with a module status frame indicating the nature of the failure.
API Operation - with Escape Characters (AP parameter = 2)
When this API mode is enabled (AP = 2), the UART data frame structure is defined as follows:
Figure 6‐02. UART Data Frame Structure ‐ with escape control characters:
Start Delimiter
(Byte 1)
0x7E
Length
(Bytes 2-3)
MSB LSB
Frame Data
(Bytes 4-n)
API-specific Structure
Checksum
(Byte n + 1)
1 Byte
Characters Escaped If Needed
MSB = Most Significant Byte, LSB = Least Significant Byte
Escape characters. When sending or receiving a UART data frame, specific data values must be escaped (flagged) so they do not interfere with the data frame sequencing. To escape an interfering data byte, insert 0x7D and follow it with the byte to be escaped XOR’d with 0x20.
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Data bytes that need to be escaped:
• 0x7E – Frame Delimiter
• 0x7D – Escape
• 0x11 – XON
• 0x13 – XOFF
Example - Raw UART Data Frame (before escaping interfering bytes):
0x7E 0x00 0x02 0x23 0x11 0xCB
0x11 needs to be escaped which results in the following frame:
0x7E 0x00 0x02 0x23 0x7D 0x31 0xCB
Note: In the above example, the length of the raw data (excluding the checksum) is 0x0002 and the checksum of the non-escaped data (excluding frame delimiter and length) is calculated as:
0xFF - (0x23 + 0x11) = (0xFF - 0x34) = 0xCB.
Length
The length field has two-byte value that specifies the number of bytes that will be contained in the frame data field. It does not include the checksum field.
Frame Data
Frame data of the UART data frame forms an API-specific structure as follows:
Figure 6‐03. UART Data Frame & API‐specific Structure:
Start Delimiter
(Byte 1)
Length
(Bytes 2-3)
Frame Data
(Bytes 4-n)
Checksum
(Byte n + 1)
0x7E
MSB LSB API-specific Structure 1 Byte
API Identifier cmdID
Identifier-specific Data cmdData
The cmdID frame (API-identifier) indicates which API messages will be contained in the cmdData frame (Identifier-specific data). Note that multi-byte values are sent big endian.The XBee modules support the following API frames:
Table 6‐016. API Frame Names and Values
API Frame Names Values
Modem Status
AT Command
0x8A
0x08
AT Command - Queue Parameter Value
0x09
AT Command Response
Remote Command Request
0x88
0x17
Remote Command Response
ZigBee Transmit Request
Explicit Addressing ZigBee Command Frame
ZigBee Transmit Status
ZigBee Receive Packet (AO=0)
ZigBee Explicit Rx Indicator (AO=1)
ZigBee IO Data Sample Rx Indicator
XBee Sensor Read Indicator (AO=0)
Node Identification Indicator (AO=0)
0x97
0x10
0x11
0x8B
0x90
0x91
(0x92)
0x94
0x95
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Checksum
To test data integrity, a checksum is calculated and verified on non-escaped data.
To calculate: Not including frame delimiters and length, add all bytes keeping only the lowest 8 bits of the result and subtract the result from 0xFF.
To verify: Add all bytes (include checksum, but not the delimiter and length). If the checksum is correct, the sum will equal 0xFF.
API Examples
Example: Create an API AT command frame to configure an XBee to allow joining (set NJ to
0xFF). The frame should look like:
0x7E 0x00 0x05 0x08 0x01 0x4E 0x4A 0xFF 5F
Where 0x0005 = length
0x08 = AT Command API frame type
0x01 = Frame ID (set to non-zero value)
0x4E4A = AT Command ('NJ')
0xFF = value to set command to
0x5F = Checksum
The checksum is calculated as [0xFF - (0x08 + 0x01 + 0x4E + 0x4A + 0xFF)]
Example: Send a transmission to a module with destination address 0x0013A200 40014011, payload "TxData1B". If escaping is disabled, (AP=1), the frame should look like:
0x7E 0x00 0x16 0x10 0x01 0x00 0x13 0xA2 0x00 0x40 0x0A 0x01 0x27 0xFF
0xFE 0x00 0x00 0x54 0x78 0x44 0x61 0x74 0x61 0x30 0x41 0x13
Where 0x16 = length (22 bytes excluding checksum)
0x10 = ZigBee Transmit Request API frame type
0x01 = Frame ID (set to non-zero value)
0x0013A200400A0127 = 64-bit Destination Address
0xFFFE = 16-bit Destination Address
0x00 = Broadcast radius
0x00 = Options
0x5478446174613041 = Data payload ("TxData0A")
0x64 = Checksum
If escaping is enabled (AP=2), the frame should look like:
0x7E 0x00 0x16 0x10 0x01 0x00 0x7D 0x33 0xA2 0x00 0x40 0x0A 0x01 0x27
0xFF 0xFE 0x00 0x00 0x54 0x78 0x44 0x61 0x74 0x61 0x30 0x41 0x7D 0x33
The checksum is calculated (on all non-escaped bytes) as [0xFF - (sum of all bytes from API frame type through data payload)].
Example: Send a transmission to the coordinator without specifying the coordinator's 64-bit address. The API transmit request frame should look like:
0x7E 0x00 0x16 0x10 0x01 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0xFF 0xFE 0x00
0x00 0x54 0x78 032 0x43 0x6F 0x6F 0x72 0x64 0xFC
Where 0x16 = length (22 bytes excluding checksum)
0x10 = ZigBee Transmit Request API frame type
0x01 = Frame ID (set to non-zero value)
0x0000000000000000 = Coordinator's address (can be replaced with coordinator's actual
64-bit address if known
0xFFFE = 16-bit Destination Address
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0x00 = Broadcast radius
0x00 = Options
0x547832436F6F7264 = Data payload ("Tx2Coord")
0xFC = Checksum
Example: Send an ND command to discover the devices in the PAN. The frame should look like:
0x7E 0x00 0x04 0x08 0x01 0x4E 0x44 0x64
Where 0x0004 = length
0x08 = AT Command API frame type
0x01 = Frame ID (set to non-zero value)
0x4E44 = AT command ('ND')
0x64 = Checksum
The checksum is calculated as [0xFF - (0x08 + 0x01 + 0x4E + 0x44)]
Example: Send a remote command to the coordinator to set AD1/DIO1 as a digital input (D1=3) and apply changes to force the IO update. The API remote command frame should look like:
0x7E 0x00 0x10 0x17 0x01 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0xFF 0xFE 0x02
0x44 0x31 0x03 0x70
Where
0x10 = length (16 bytes excluding checksum)
0x17 = Remote Command API frame type
0x01 = Frame ID
0x0000000000000000 = Coordinator's address (can be replaced with coordinator's actual 64bit address if known)
0xFFFE = 16- bit Destination Address
0x02 = Apply Changes (Remote Command Options)
0x4431 = AT command ('D1')
0x03 = Command Parameter (the parameter could also be sent as 0x0003 or 0x00000003)
0x70 = Checksum
Supporting the API
Applications that support the API should make provisions to deal with new API frames that may be introduced in future releases. For example, a section of code on a host microprocessor that handles received serial API frames (sent out the module's DOUT pin) might look like this:
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void XBee_HandleRxAPIFrame(_apiFrameUnion *papiFrame){
switch(papiFrame->api_id){
case RX_RF_DATA_FRAME:
//process received RF data frame
break;
case RX_IO_SAMPLE_FRAME:
//process IO sample frame
break;
case NODE_IDENTIFICATION_FRAME:
//process node identification frame
break;
default:
//Discard any other API frame types that are not being used
break;
}
}
API Frames
The following sections illustrate the types of frames encountered while using the API.
Note: The following information is missing or incorrect in the API graphics:
• Transmit option 0x08 is not supported
• The maximum RF data payload in an API transmit frame is not 72 bytes (several images are incorrect). The maximum RF data payload can be read using the NP command. See the command table for details.
The following information is not shown in the API graphics:
• The 64-bit destination address can be set to 0 as an alternate address for the coordinator.
• The maximum broadcast radius is 32.
• The NO command can be used to include the DD parameter in the Node Identification Indicator (0x95).
Modem Status
API Identifier Value: (0x8A)
RF module status messages are sent from the module in response to specific conditions.
Figure 6‐04. Modem Status Frames
S ta rt D e lim ite r
0 x 7 E M S B
L e n g th
L S B
A P I Id e n tifie r
0 x 8 A
F ra m e D a ta
A P I-s p e c ific S tru c tu re
Id e n tifie r-s p e c ific D a ta
c m d D a ta
C h e c k s u m
1 B y te
S ta tu s (B y te 5 )
0 = H a rd w a re re s e t
1 = W a tc h d o g tim e r re s e t
2 = A s s o c ia te d
3 = D is a s s o c ia te d
4 = S y n c h ro n iz a tio n L o s t
(B e a c o n -e n a b le d o n ly)
5 = C o o rd in a to r re a lig n m e n t
6 = C o o rd in a to r s ta rte d
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AT Command
API Identifier Value: 0x08
Allows for module parameter registers to be queried or set.
Figure 6‐5.
AT Command Frames
Start Delimiter
0x7E MSB
Length
LSB
API Identifier
0x08
Frame Data
API-specific Structure
Identifier-specific Data cmdData
Checksum
1 Byte
Frame ID (Byte 5)
Identifies the UART data frame for the host to correlate with a subsequent ACK (acknowledgement).
If set to ‘0’, no response is sent.
AT Command (Bytes 6-7)
Command Name - Two
ASCII characters that identify the AT Command.
Parameter Value (Byte(s) 8-n)
If present, indicates the requested parameter value to set the given register.
If no characters present, register is queried.
Figure 6‐6.
Example: API frames when reading the NJ parameter value of the module.
Byte 1
0x7E
Bytes 2-3
0x00 0x04
Byte 4
0x08
Byte 5
0x52 (R)
Start Delimiter Length* API Identifier Frame ID**
* Length [Bytes] = API Identifier + Frame ID + AT Command
** “R” value was arbitrarily selected.
Bytes 6-7
0x4E (N) 0x4A (J)
AT Command
Byte 8
0x0D
Checksum
Figure 6‐7.
Example: API frames when modifying the NJ parameter value of the module.
Byte 1
0x7E
Bytes 2-3
0x00 0x05
Byte 4
0x08
Byte 5
0x4D (M)
Bytes 6-7
0x4E (N) 0x4A (J)
Start Delimiter Length* API Identifier Frame ID** AT Command
* Length [Bytes] = API Identifier + Frame ID + AT Command + Parameter Value
** “M” value was arbitrarily selected.
Bytes 8
0x40
Byte 9
0xD2
Parameter Value Checksum
A string parameter used with the NI (Node Identifier), ND (Node Discover) and DH (Destination
Address High) command is terminated with a 0x00 character.
AT Command - Queue Parameter Value
API Identifier Value: 0x09
This API type allows module parameters to be queried or set. In contrast to the “AT Command”
API type, new parameter values are queued and not applied until either the “AT Command” (0x08)
API type or the AC (Apply Changes) command is issued. Register queries (reading parameter values) are returned immediately.
Figure 6‐8.
AT Command Frames
(Note that frames are identical to the “AT Command” API type except for the API identifier.)
Start Delimiter
0x7E MSB
Length
LSB
API Identifier
0x09
Frame Data
API-specific Structure
Identifier-specific Data cmdData
Checksum
1 Byte
Frame ID (Byte 5)
Identifies the UART data frame for the host to correlate with a subsequent ACK (acknowledgement).
If set to ‘0’, no response is sent.
AT Command (Bytes 6-7)
Command Name - Two
ASCII characters that identify the AT Command.
Parameter Value (Byte(s) 8-n)
If present, indicates the requested parameter value to set the given register.
If no characters present, register is queried.
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XBee®/XBee‐PRO® ZB OEM RF Modules
AT Command Response
API Identifier Value: 0x88
Response to previous command.
In response to an AT Command message, the module will send an AT Command Response message. Some commands will send back multiple frames (for example, the ND (Node Discover) command).
Figure 6‐9.
AT Command Response Frames.
Start Delimiter
0x7E
Length
MSB LSB
API Identifier
0x88
Frame Data
API-specific Structure
Identifier-specific Data cmdData
Checksum
1 Byte
Frame ID (Byte 5 )
Identifies the UART data frame being reported.
Note: If Frame ID = 0 in AT Command Mode, no AT Command Response will be given.
AT Command (Bytes 6-7)
Command Name - Two
ASCII characters that identify the AT Command.
Status (Byte 8)
0 = OK
1 = ERROR
2 = Invalid Command
3 = Invalid Parameter
Value (Byte(s) 9-n)
The HEX (non-ASCII) value of the requested register
Start Delimiter
0x7E
Remote AT Command Request
API Identifier Value: 0x17
Allows for module parameter registers on a remote device to be queried or set
Figure 6‐10. Remote AT Command Request
MSB
Length
LSB
Frame Data
API-specific Structure
Checksum
1 Byte
API Identifier
0x17
Identifier-specific Data cmdData
Frame ID (Byte 5)
Identifies the UART data frame for the host to correlate with a subsequent ACK (acknowledgement).
If set to ‘0’, no AT Command Response will be given.
64-bit Destination Address
(bytes 6-13)
Set to match the 64-bit address of the destination, MSB first,
LSB last. Broadcast =
0x000000000000FFFF.
16-bit Destination Network Address
(bytes 14-15)
Set to match the 16-bit network address of the destination, MSB first, LSB last. Set to 0xFFFE for broadcast TX, or if the network address is unknown.
Command Name (bytes
17-18)
Name of the command
Command Options (byte 16)
0x02 - Apply changes on remote. (If not set, AC command must be sent before changes will take effect.)
All other bits must be set to 0.
Command Data (byte 19-n)
If present, indicates the requested parameter value to set the given register. If no characters present, the register is queried.
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Remote Command Response
API Identifier Value: 0x97
If a module receives a remote command response RF data frame in response to a Remote AT
Command Request, the module will send a Remote AT Command Response message out the
UART. Some commands may send back multiple frames--for example, Node Discover (ND) command.
Start Delimiter
0x7E
Figure 6‐11. Remote AT Command Response.
Length Frame Data Checksum
MSB LSB API-specific Structure 1 Byte
API Identifier
0x97
Identifier-specific Data cmdData
Frame ID (Byte 5)
Identifies the UART data frame being reported.
Matches the Frame ID of the Remote Command
Request the remote is responding to.
64-bit Responder
Address (bytes 6-13)
16-bit Responder Network Address (bytes
14-15)
Indicates the 64-bit address of the remote module that is responding to the Remote
AT Command request
Set to the 16-bit network address of the remote.
Set to 0xFFFE if unknown.
Command Name (bytes
16-17)
Name of the command. Two
ASCII characters that identify the AT command
Status (byte 18)
0 = OK
1 = Error
2 = Invalid Command
3 = Invalid Parameter
Command Data (byte 19-n)
The value of the requested register.
ZigBee Transmit Request
API Identifier Value: 0x10
A TX Request message will cause the module to send RF Data as an RF Packet.TX Packet Frames
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Figure 6‐12. ZigBee Transmit Request.
Start Delimiter
0x7E
Length
MSB LSB
API Identifier
0x10
Frame Data
API-specific Structure
Identifier-specific Data cmdData
Checksum
1 Byte
Frame ID (Byte 5)
Identifies the UART data frame for the host to correlate with a subsequent ACK (acknowledgement).
Setting Frame ID to ‘0' will disable response frame.
16-bit Destination
Network Address (Bytes 14-15)
MSB first, LSB last.
Set to 0xFFFE for
Broadcast TX or if Network
Address is not known
Options (Byte 17)
0x08 =Send multicast transmission.
(Unicast set if not sent.) All other bits must be set to 0.
RF Data (Byte(s) 18-n)
Up to 72 Bytes per packet
64-bit Destination
Address (Bytes 6-13)
MSB first, LSB last.
Broadcast =
0x000000000000FFFF
Broadcast Radius (Byte 16)
Sets maximum number of hops a braodcast transmission can traverse. If set to 0, the TX raidus will be set to the maximum hop value (10).
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Explicit Addressing ZigBee Command Frame
API Identifier Value: 0x11
Allows ZigBee application layer fields (endpoint and cluster ID) to be specified for a data transmission.
Figure 6‐13. Explicit Addressing ZigBee Command Frame.
Start delimiter
0x7E MSB
Length
LSB
Frame Data
API-specific Structure
API Identifier
0x11
Checksum
1 Byte
Identifier specific data cmdData
Frame ID (byte 5)
Identifies the UART data frame for the host correlate with a subsequent ACK
(acknowledgement). Setting Frame ID to ‘0’ will disable response frame.
64-bit Destination Address (bytes 6-13)
Destination 64-bit (extended) address. Set to 0xFFFF for broadcast, or to all 0x00's to send to the coordinator
1
2
16-bit Destination Network Address (byted 14-15)
3
Destination network address (if known). Set to
0xFFFE for broadcast transmissions or if the destination network address is not known.
Source endpoint (byte 16)
Source endpoint for the transmission.
4
Destination endpoint (byte 17)
Destination endpoint for the transmission.
5
6
Cluster ID (byte 18-19)
7
Cluster ID used in the transmission
Profile ID (bytes 20-21)
Profile ID used in the transmission
8 Broadcast Radius (byte 22)
Sets the maximum number of hops a broadcast transmission can traverse. If set to 0, the transmission radius will be set to the network maximum hops value.
9
Options (byte 23)
Set to 0
10
RF Data (byte 24-n)
RF data size must be less than or equal to the maximum number of
RF data bytes (NP command).
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ZigBee Transmit Status
API Identifier Value: 0x8B
When a TX Request is completed, the module sends a TX Status message. This message will indicate if the packet was transmitted successfully or if there was a failure.
Figure 6‐14. TX Status Frames
Start Delimiter
0x7E MSB
Length
LSB
API Identifier
0x8B
Frame Data
API-specific Structure
Identifier-specific Data cmdData
Checksum
1 Byte
Frame ID (Byte 5) Remote Network Address (Bytes 6-7) Transmit Retry Count (Byte 8)
Identifies UART data frame being reported.
16-bit Network Address the packet was delivered to (if success). If not success, this address matches the
Destination Network Address that was provided in the
Transmit Request Frame.
The number of application transmission retries that took place.
Delivery Status (Byte 9)
0x00 = Success
0x02 = CCA Failure
0x15 = Invalid destination endpoint
0x21 = Network ACK Failure
0x22 = Not Joined to Network
0x23 = Self-addressed
0x24 = Address Not Found
0x25 = Route Not Found
Discovery Status (Byte 10)
0x00 = No Discovery
Overhead
0x01 = Address Discovery
0x02 = Route Discovery
0x03 = Address and Route
Discovery
ZigBee Receive Packet
API Identifier Value: (0x90)
When the module receives an RF packet, it is sent out the UART using this message type.
Figure 6‐15. RX Packet Frames
Start Delimiter
0x7E MSB
Length
LSB
API Identifier
0x90
Frame Data
API-specific Structure
Identifier-specific Data cmdData
Checksum
1 Byte
64-bit Address
(Bytes 5-12)
16-bit Network Address
(Bytes 13-14)
MSB (most significant byte) first,
LSB (least significant) last
MSB (most significant byte) first,
LSB (least significant) last
Options
(Byte 15)
0x01 - Packet Acknowledged
0x02 - Packet was a broadcast packet
RF Data
(Byte(s) 16-n)
Up to 72 Bytes per packet
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ZigBee Explicit Rx Indicator
Start delimiter
API Identifier Value:0x91
When the modem receives a ZigBee RF packet it is sent out the UART using this message type
(when AO=1).
Figure 6‐16. ZigBee Explicit Rx Indicators
Length Frame Data Checksum
0x7E MSB LSB API-specific Structure 1 Byte
API Identifier
0x91
Identifier specific data cmdData
64-bit Source address (bytes 5-12)
Destination 64-bit (extended) address. Set to 0xFFFF for broadcast.
1
2
16-bit Source network address (13-14)
Destination network address (if known). Set to 0xFFFE for broadcast transmissions or if the destination network address is not known.
6
5
Cluster ID (byte 17-18)
Cluster ID the packet was addressed to.
Profile ID (byte 19-20)
Profile ID the packet was addressed to. (Multiple profile IDs not yet supported.)
3
7
Options (byte 21)
0x01 – Packet Acknowledged
0x02 – Packet was a broadcast packet
Source endpoint (byte 15)
Endpoint of the source that initiated the transmission
Destination endpoint (byte 16)
Endpoint of the destination the message is addressed to.
4
8
RF data (byte 22-n)
Up to 72 bytes.
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ZigBee IO Data Sample Rx Indicator
API Identifier Value: 0x92
When the module receives an IO sample frame from a remote device, it sends the sample out the
UART using this frame type.
Figure 6‐17. IO Data Sample Rx Indicators
Start Delimiter Length Frame Data
0x7E MSB LSB API-specific Structure
Checksum
1 Byte
API Identifier
0x92
Identifier-specific Data cmdData
64-bit Address
(Bytes 5-12)
MSB (most significant byte) first,
LSB (least significant) last
Receive Options
(Byte 15)
0x01 - Packet Acknowledged
0x02 - Packet was a broadcast packet
Digital Samples (bytes 20-
21, if included)
Digital Channel Mask
(bytes 17-18)*
Bitmask field that indicates which digital IO lines on the remote have sampling enabled (if any)
If the sample set includes any digital IO lines
(Digital Channel Mask > 0), these two bytes contain samples for all enabled digital inputs.
DIO lines that do not have sampling enabled return 0. Bits in these 2 bytes map the same as they do in the Digital Channels Mask field.
Analog Samples (2 bytes each sample)
16-bit Network Address
(Bytes 13-14)
MSB (most significant byte) first,
LSB (least significant) last
Num Samples (byte 16)
Number of sample sets included in the payload.
(Always set to 1)
Analog Channel Mask
(byte 19)**
Bitmask field that indicates which digital IO lines on the remote have sampling enabled (if any).
If the sample set includes any analog input lines
(Analog Channel Mask > 0), each enabled analog input returns a 2-byte value indicating the A/D measurement of that input. Analog samples are ordered sequentially from AD0/DIO0 to AD3/DIO3, to the supply voltage.
*
N/A N/A
CTS/DI
O7
RTS/DI
O6
N/A
ASSOC/
DIO5
CD/DIO
12
PWM/DI
O11
DIO4 AD3/DI
O3
RSSI/DI
O10
AD2/DI
O2
N/A
AD1/DI
O1
N/A
AD0/DI
O0
** Supply
Voltage
N/A N/A N/A AD3 AD2 AD1 AD0
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XBee®/XBee‐PRO® ZB OEM RF Modules
XBee Sensor Read Indicator
API Identifier Value: 0x94
When the module receives a sensor sample, it is sent out the UART using this message type (when
AO=0).
Figure 6‐18. XBee Sensor Read Indicator (0x94)
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XBee®/XBee‐PRO® ZB OEM RF Modules
Node Identification Indicator
API Identifier Value: 0x95
This frame is received on the coordinator when a module transmits a node identification message to identify itself to the coordinator (when AO=0). The data portion of this frame is similar to a
Node Discovery response frame (see ND command).
Figure 6‐19. Node Identification Indicator
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7. XBee Command Reference Tables
Special
Table 7‐01. Special Commands
AT
Command
Name and Description
WR
RE
FR
NR
Node Type
Write. Write parameter values to non-volatile memory so that parameter modifications persist through subsequent resets.
Note: Once WR is issued, no additional characters should be sent to the module until after the "OK\r" response is received. The WR command should be used sparingly. The
EM250 supports a limited number of write cycles.“
Restore Defaults. Restore module parameters to factory defaults. RE command does not reset the ID parameter.
CRE
CRE
Software Reset. Reset module. Responds immediately with an “OK” then performs a reset ~2 seconds later. Use of the FR command will cause a network layer restart on the node if SC or ID were modified since the last reset.
CRE
Network Reset. Reset network layer parameters on one or more modules within a PAN.
Responds immediately with an “OK” then causes a network restart. All network configuration and routing information is consequently lost.
If NR = 0: Resets network layer parameters on the node issuing the command.
If NR = 1: Sends broadcast transmission to reset network layer parameters on all nodes in the PAN.
CRE
1
Node types that support the command: C = Coordinator, R = Router, E = End Device
Parameter Range Default
--
--
--
0 - 1
--
--
--
--
Addressing
Table 7‐02. Addressing Commands)
AT
Command
DH
DL
2
2
Name and Description
Node
Type
1
Destination Address High. Set/Get the upper 32 bits of the 64-bit destination address.
When combined with DL, it defines the destination address used for transmission.
0x000000000000FFFF is the broadcast address for the PAN. DH is not supported in
API Mode. 0x0000000000000000 is the Coordinator’s 16-bit network address.
Destination Address Low. Set/Get the lower 32 bits of the 64-bit destination address.
When combined with DH, DL defines the destination address used for transmission.
0x000000000000FFFF is the broadcast address for the PAN. DL is not supported in
API Mode. 0x0000000000000000 is the Coordinator’s 16-bit network address.
CRE
CRE
Parameter Range
0 - 0xFFFFFFFF
0 - 0xFFFFFFFF
MY
MP
16-bit Network Address. Get the 16-bit network address of the module.
CRE
16-bit Parent Network Address. Get the 16-bit parent network address of the module. E
0 - 0xFFFE
[read-only]
0 - 0xFFFE
[read-only]
NC
SH
SL
NI
DD
SE
DE
2
2
Number of Remaining Children. Read the number of end device children that can join the device. If NC returns 0, then the device cannot allow any more end device children to join.
Serial Number High. Read high 32 bits of the RF module's unique IEEE 64-bit address. 64-bit source address is always enabled.
Serial Number Low. Read low 32 bits of the RF module's unique IEEE 64-bit address.
64-bit source address is always enabled.
Node Identifier. Stores a string identifier. The register only accepts printable ASCII data. In AT Command Mode, a string can not start with a space. A carriage return ends the command. Command will automatically end when maximum bytes for the string have been entered. This string is returned as part of the ND (Node Discover) command.
This identifier is also used with the DN (Destination Node) command.
Device Type Identifier. Stores a device type value. This value can be used to differentiate multiple XBee-based products.
Source Endpoint. Set/read the ZigBee application layer source endpoint value. If
ZigBee application layer addressing is enabled (ZA command), this value will be used as the source endpoint for all data transmissions. SE is only supported in AT firmware.The default value 0xE8 (Data endpoint) is the Digi data endpoint
Destination Endpoint. Set/read Zigbee application layer destination ID value. If
ZigBee application layer addressing is enabled (ZA command), this value will be used as the destination endpoint all data transmissions. DE is only supported in AT firmware.The default value (0xE8) is the Digi data endpoint.
CR
CRE
CRE
CRE
CRE
CRE
CRE
0 - 10
0 - 0xFFFFFFFF
[read-only]
0 - 0xFFFFFFFF
[read-only]
20-Byte printable
ASCII string
0 - 0xFFFFFFFF [readonly]
0 - 0xFF
0 - 0xFF
Default
0
0xFFFF(Coordinator)
0 (Router/End Device)
0xFFFE
0xFFFE read-only factory-set factory-set
ASCII space character (0x20)
0x30000
0xE8
0xE8
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Table 7‐02. Addressing Commands)
AT
Command
CI
2
NP
Name and Description
Node
Type
1
Cluster Identifier. Set/read Zigbee application layer cluster ID value. If ZigBee application layer addressing is enabled (ZA command), this value will be used as the cluster ID for all data transmissions. CI is only supported in AT firmware.The default value0x11 (Transparent data cluster ID).
Maximum RF Payload Bytes. This value returns the maximum number of RF payload bytes that can be sent in a unicast transmission.
CRE
CRE
Parameter Range
0 - 0xFFFF
0 - 0xFFFF
Default
0x11
[read-only]
1. Node types that support the command: C=Coordinator, R=Router, E=End Device
2. Command supported by modules using AT Command firmware only
Networking
Table 7‐03. Networking Commands
AT
Command
CH
EI
OE
NH
BH
OP
NT
NO
Name and Description
Node
Type
1
Operating Channel. Read the channel number used for transmitting and receiving between RF modules. Uses 802.15.4 channel numbers. A value of 0 means the device has not joined a PAN and is not operating on any channel.
Extended PAN ID. Set/read the 64-bit extended PAN ID. If set to 0, the coordinator will select a random extended PAN ID, and the router / end device will join any extended PAN ID. Changes to EI should be written to non-volatile memory using the
WR command.
Operating Extended PAN ID. Read the 64-bit extended PAN ID. The OE value reflects the operating extended PAN ID that the module is running on. If EI > 0, OE will equal EI.
Maximum Unicast Hops. Set / read the maximum hops limit. This limit sets the maximum broadcast hops value (BH) and determines the unicast timeout. The timeout is computed as (50 * NH) + 100 ms. The default unicast timeout of 1.6 seconds
(NH=0x1E) is enough time for data and the acknowledgment to traverse about 8 hops.
Broadcast Hops. Set/Read the maximum number of hops for each broadcast data transmission. Setting this to 0 will use the maximum number of hops.
Operating PAN ID. Read the PAN (Personal Area Network) ID. The OP value reflects the operating PAN ID that the module is running on. If ID < 0xFFFF, OP will equal ID.
Node Discover Timeout. Set/Read the amount of time a node will spend discovering other nodes when ND or DN is issued.
Network Discovery options. Set/Read the options value for the network discovery command. The options bitfield value can change the behavior of the ND (network discovery) command and/or change what optional values are returned in any received
ND responses or API node identification frames. Options include:
0x01 = Append DD value (to ND responses or API node identification frames)
002 = Local device sends ND response frame when ND is issued.
CRE
CRE
CRE
CRE
CRE
CRE
CRE
CRE
Parameter Range
0, 0x0B - 0x1A (XBee)
0, 0x0B - 0x18 (XBee-
PRO)
0 -
0xFFFFFFFFFFFFFFFF
0x01 -
0xFFFFFFFFFFFFFFFF
0 - 0xFF
0 - 0x20
0 - 0x3FFF
0 - 0x03 [bitfield]
Default
[read-only]
0
[read-only]
0x1E
0
[read-only]
0x20 - 0xFF [x 100 msec] 0x3C (60d)
0
ND
Node Discover. Discovers and reports all RF modules found. The following information is reported for each module discovered.
MY<CR>
SH<CR>
SL<CR>
NI<CR> (Variable length)
PARENT_NETWORK ADDRESS (2 Bytes)<CR>
DEVICE_TYPE<CR> (1 Byte: 0=Coord, 1=Router, 2=End Device)
STATUS<CR> (1 Byte: Reserved)
PROFILE_ID<CR> (2 Bytes)
MANUFACTURER_ID<CR> (2 Bytes)
<CR>
After (NT * 100) milliseconds, the command ends by returning a <CR>. ND also accepts a Node Identifier (NI) as a parameter (optional). In this case, only a module that matches the supplied identifier will respond.
If ND is sent through the API, each response is returned as a separate
AT_CMD_Response packet. The data consists of the above listed bytes without the carriage return delimiters. The NI string will end in a "0x00" null character. The radius of the ND command is set by the BH command.
CRE optional 20-Byte
NI or MY value
--
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Table 7‐03. Networking Commands
AT
Command
DN
SC
Name and Description
Node
Type
1
Destination Node. Resolves an NI (Node Identifier) string to a physical address (casesensitive). The following events occur after the destination node is discovered:
<AT Firmware>
1. DL & DH are set to the extended (64-bit) address of the module with the matching
NI (Node Identifier) string.
2. OK (or ERROR)\r is returned.
3. Command Mode is exited to allow immediate communication
<API Firmware>
1. The 16-bit network and 64-bit extended addresses are returned in an API
Command Response frame.
If there is no response from a module within (NT * 100) milliseconds or a parameter is not specified (left blank), the command is terminated and an “ERROR” message is returned. In the case of an ERROR, Command Mode is not exited. The radius of the DN command is set by the BH command.
Scan Channels. Set/Read the list of channels to scan.
Coordinator - Bit field list of channels to choose from prior to starting network.
Router/End Device - Bit field list of channels that will be scanned to find a Coordinator/
Router to join.
Changes to SC should be written using WR command.
Bit (Channel): 0 (0x0B)
1 (0x0C)
2 (0x0D)
3 (0x0E)
4 (0x0F)
5 (0x10)
6 (0x11)
7 (0x12)
8 (0x13)
9 (0x14)
10 (0x15)
11 (0x16)
12 (0x17)
13 (0x18)
14 (0x19)
15 (0x1A)
CRE
CRE
Parameter Range
up to 20-Byte printable
ASCII string
XBee
1 - 0xFFFF [bitfield]
XBee-PRO
1 - 0x3FFF [bitfield]
(bits 14, 15 not allowed)
Note: Setting SC to include more than 12 continuous channels could cause data to be received on incorrect frequencies due to crosstalk issues with the EM250 at certain power levels. See Appendix E for details.
SD
ZS
NJ
JV
JN
AR
Changing SC may result in not being able to communicate with long-range ‘-PRO’ modules from Digi
Scan Duration. Set/Read the scan duration exponent. Changes to SD should be written using WR command.
Coordinator - Duration of the Active and Energy Scans (on each channel) that are used to determine an acceptable channel and Pan ID for the Coordinator to startup on.
Router / End Device - Duration of Active Scan (on each channel) used to locate an available Coordinator / Router to join during Association.
Scan Time is measured as:(# Channels to Scan) * (2 ^ SD) * 15.36ms - The number of channels to scan is determined by the SC parameter. The XBee can scan up to 16 channels (SC = 0xFFFF).
Sample Scan Duration times (13 channel scan):
If SD = 0, time = 0.200 sec
SD = 2, time = 0.799 sec
SD = 4, time = 3.190 sec
SD = 6, time = 12.780 sec
ZigBee Stack Profile. Set / read the ZigBee stack profile value. This must be set the same on all devices that should join the same network.
Node Join Time. Set/Read the time that a Coordinator/Router allows nodes to join.
This value can be changed at run time without requiring a Coordinator or Router to restart. The time starts once the Coordinator or Router has started. The timer is reset on power-cycle or when NJ changes.
Channel Verification. Set/Read the channel verification parameter. If JV=1, and the network is an open network (NJ=0xFF), a router will verify the coordinator is on its operating channel when joining or coming up from a power cycle. If a coordinator is not detected, the router will leave its current channel and attempt to join a new PAN. If
JV=0, the router will continue operating on its current channel even if a coordinator is not detected.
Join Notification. Set / read the join notification setting. If enabled, the module will transmit a broadcast node identification packet on power up and when joining. This action blinks the Associate LED rapidly on all devices that receive the transmission, and sends an API frame out the UART of API devices. This feature should be disabled for large networks to prevent excessive broadcasts.
Aggregate Routing Notification. Set/read time between consecutive aggregate route broadcast messages. If used, AR should be set on only one device to enable many-toone routing to the device. Setting AR to 0 only sends one broadcast
CRE
CRE
CR
R
RE
CR
0 - 7 [exponent]
0 - 2
0 - 0xFF
[x 1 sec]
0 - Channel verification disabled
1 - Channel verification enabled
0 - 1
0 - 0xFF
Default
--
0x3FFF.
3
0
0xFF
(always allows joining)
0
1
0xFF
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Table 7‐03. Networking Commands
AT
Command
AI
Name and Description
Node
Type
1
Association Indication. Read information regarding last node join request:
0x00 - Successful completion - Coordinator started or Router/End Device found and joined with a parent.
0xAB - Attempted to join a device that did not respond.
0xAC - Secure join error - network security key received unsecured
0xAD - Secure join error - network security key not received
0xAF - Secure join error - joining device does not have the right preconfigured link key
0x21 - Scan found no PANs
0x22 - Scan found no valid PANs based on current SC and ID settings
0x23 - Valid Coordinator or Routers found, but they are not allowing joining (NJ expired)
0x27 - Node Joining attempt failed (typically due to incompatible security settings)
0x2A - Coordinator Start attempt failed‘
0xFF - Scanning for a Parent
0x2B - Checking for an existing coordinator
CRE
Parameter Range
0 - 0xFF
[read-only]
Default
--
Security
Table 7‐04. Security Commands
AT
Command
EE
EO
KY
LK
Name and Description
Encryption Enable. Set/Read the encryption enable setting.
Node
Type
1
Parameter Range Default
CRE
0 - Encryption disabled
1 - Encryption enabled
0
Encryption Options. Configure options for encryption. Unused option bits should be set to 0. Options include:
0x01 - Send the security key unsecured over-the-air during joins
0x02 - Use trust center
Encryption Key. Set the 128-bit AES encryption key. This command is read-only; KY cannot be read.
Link Key. Set the 128-bit AES link key. This command is write only; LK cannot be read.
Setting LK to 0 will cause the coordinator to transmit the network key in the clear to joining devices, and will cause joining devices to acquire the network key in the clear when joining.
CRE
C
CRE
0 - 0xFF
0 -
0xFFFFFFFFFFFFFFFF 0
0 -
0xFFFFFFFFFFFFFFFF 0
RF Interfacing
Table 7‐05. RF Interfacing Commands
AT
Command
PL
Name and Description
Power Level. Select/Read the power level at which the RF module transmits conducted power.
Node
Type
1
Parameter Range Default
CRE
XBee
(boost mode disabled)
0 = -8 dBm
1 = -4 dBm
2 = -2 dBm
3 = 0 dBm
4 = +2 dBm
4
PM
DB
Power Mode. Set/read the power mode of the device. Enabling boost mode will improve the receive sensitivity by 1dB and increase the transmit power by 2dB
Note: Enabling boost mode on the XBee-PRO will not affect the output power. Boost mode imposes a slight increase in current draw. See section 1.2 for details.
Received Signal Strength. This command reports the received signal strength of the last received RF data packet. The DB command only indicates the signal strength of the last hop. It does not provide an accurate quality measurement for a multihop link. DB can be set to 0 to clear it.
CRE
XBee-PRO
4 = 17 dBm
XBee-PRO
(International Variant)
4 = 10dBm
0-1,
0= -Boost mode disabled,
1= Boost mode enabled. 1
1. Node types that support the command: C = Coordinator, R = Router, E = End Device
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Serial Interfacing (I/O)
Table 7‐06. Serial Interfacing Commands
AT
Command
AP
AO
BD
NB
2
2
Name and Description
API Enable. Enable API Mode.
The AP parameter is only applicable when using modules that contain the following firmware versions:1.1xx (coordinator), 1.3xx (router/end device)
API Options. Configure options for API. Current options select the type of receive API frame to send out the Uart for received RF data packets.
Interface Data Rate. Set/Read the serial interface data rate for communication between the module serial port and host.
Any value above 0x07 will be interpreted as an actual baud rate. When a value above
0x07 is sent, the closest interface data rate represented by the number is stored in the
BD register.
Serial Parity. Set/Read the serial parity setting on the module.
Node
Type
1
Parameter Range Default
CRE
CRE
CRE
CRE
1 - 2
1 = API-enabled
2 = API-enabled
(w/escaped control
characters)
0 - Default receive API indicators enabled
1 - Explicit Rx data indicator API frame enabled (0x91)
0 - 7
(standard baud rates)
0 = 1200 bps
1 = 2400
2 = 4800
3 = 9600
4 = 19200
5 = 38400
6 = 57600
7 = 115200
0x80 - 0x38400
(non-standard rates)
0 = No parity
1 = Even parity
2 = Odd parity
3 = Mark parity
1
0
3
0
RO
Packetization Timeout. Set/Read number of character times of inter-character silence required before packetization. Set (RO=0) to transmit characters as they arrive instead of buffering them into one RF packet.
CRE
0 - 0xFF
[x character times]
3
D7
D6
DIO7 Configuration. Select/Read options for the DIO7 line of the RF module.
DIO6 Configuration. Configure options for the DIO6 line of the RF module.
CRE
CRE
0 = Disabled
1 = CTS Flow Control
3 = Digital input
4 = Digital output, low
5 = Digital output, high
6 = RS-485 transmit enable (low enable)
7 = RS-485 transmit enable (high enable)
0 - Disabled
1 - RTS Flow Control
1
0
1. Node types that support the command: C = Coordinator, R = Router, E = End Device
2. Command supported by modules using API firmware only
I/O Commands
Table 7‐07. I/O Commands
AT
Command
Name and Description
IS
1S
IR
IC
Node
Type
Force Sample Forces a read of all enabled digital and analog input lines.
CRE
XBee Sensor Sample. Forces a sample to be taken on an XBee Sensor device. This command can only be issued to an XBee sensor device using an API remote command. RE
IO Sample Rate. Set/Read the IO sample rate to enable periodic sampling. For periodic sampling to be enabled, IR must be set to a non-zero value, and at least one module pin must have analog or digital IO functionality enabled (see D0-D8, P0-P2 commands).
The sample rate is measured in milliseconds.
IO Digital Change Detection. Set/Read the digital IO pins to monitor for changes in the
IO state. IC works with the individual pin configuration commands (D0-D8, P0-P2). If a pin is enabled as a digital input/output, the IC command can be used to force an immediate IO sample transmission when the DIO state changes. IC is a bitmask that can be used to enable or disable edge detection on individual channels. Unused bits should be set to 0.
Bit (IO pin): 0 (DIO0)4 (DIO4)8 (DIO8)
1 (DIO1) 5 (DIO5) 9 (DIO9)
2 (DIO2) 6 (DIO6) 10 (DIO10)
3 (DIO3) 7 (DIO7) 11 (DIO11)
R
R
1
-
Parameter Range Default
--
0 - 0xFFFF (ms)
: 0 - 0xFFFF
-
--
0
0
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Table 7‐07. I/O Commands
AT
Command
Name and Description
P0
P1
P2
P3
D0
D1
D2
D3
D4
PWM0 Configuration. Select/Read function for PWM0.
DIO11 Configuration. Configure options for the DIO11 line of the RF module.
DIO12 Configuration. Configure options for the DIO12 line of the RF module.
DIO13 Configuration. Set/Read function for DIO13. This command is not yet supported.
AD0/DIO0 Configuration. Select/Read function for AD0/DIO0.
AD1/DIO1 Configuration. Select/Read function for AD1/DIO1.
AD2/DIO2 Configuration. Select/Read function for AD2/DIO2.
AD3/DIO3 Configuration. Select/Read function for AD3/DIO3.
DIO4 Configuration. Select/Read function for DIO4.
Node
Type
1
Parameter Range Default
CRE
CRE
CRE
0 = Disabled
1 = RSSI PWM
3 - Digital input, monitored
4 - Digital output, default low
5 - Digital output, default high
0 - Unmonitored digital input
3- Digital input, monitored
4- Digital output, default low
5- Digital output, default high
0 - Unmonitored digital input
3- Digital input, monitored
4- Digital output, default low
5- Digital output, default high
1
0
0
CRE
CRE
CRE
CRE
0, 3-5
0 – Disabled
3 – Digital input
4 – Digital output, low
5 – Digital output, high
0-5
0 – Disabled
1 - Node identification button enabled
2 - Analog input, single ended
3 – Digital input
4 – Digital output, low
5 – Digital output, high
0, 2-5
0 – Disabled
2 - Analog input, single ended
3 – Digital input
4 – Digital output, low
5 – Digital output, high
0, 2-5
0 – Disabled
2 - Analog input, single ended
3 – Digital input
4 – Digital output, low
5 – Digital output, high
1
0
0
CRE
CRE
0, 2-5
0 – Disabled
2 - Analog input, single ended
3 – Digital input
4 – Digital output, low
5 – Digital output, high
0, 3-5
0 – Disabled
3 – Digital input
4 – Digital output, low
5 – Digital output, high
0
0
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Table 7‐07. I/O Commands
AT
Command
D5
LT
Name and Description
DIO5 Configuration. Configure options for the DIO5 line of the RF module.
Node
Type
1
Parameter Range Default
CRE
0 = Disabled
1 = Associated
indication LED
3 = Digital input
4 = Digital output, default low
5 = Digital output, default high
1
Assoc LED Blink Time. Set/Read the Associate LED blink time. If the Associate LED functionality is enabled (D5 command), this value determines the on and off blink times for the LED when the module has joined a network. If LT=0, the default blink rate will be used (500ms coordinator, 250ms router/end device). For all other LT values, LT is measured in 10ms.
CRE
0x14 - 0xFF (200 - 2550 ms)
0
D8 DIO8 Configuration. Set/Read function for DIO8. This command is not yet supported. CRE
0, 3-5
0 – Disabled
3 – Digital input
4 – Digital output, low
5 – Digital output, high
PR
RP
CB
Set/read the bit field that configures the internal pull-up resistor status for the I/O lines.
"1" specifies the pull-up resistor is enabled. "0" specifies no pullup.(30k pull-up resistors)
Bits:"
0 - DIO4 (Pin 11)
1 - AD3 / DIO3 (Pin 17)
2 - AD2 / DIO2 (Pin 18)
3 - AD1 / DIO1 (Pin 19)
4 - AD0 / DIO0 (Pin 20)
5 - RTS / DIO6 (Pin 16)
6 - DTR / Sleep Request / DIO8 (Pin 9)
7 - DIN / Config (Pin 3)
8 - Associate / DIO5 (Pin 15)
9 - On/Sleep / DIO9 (Pin 13)
10 - DIO12 (Pin 4)
11 - PWM0 / RSSI / DIO10 (Pin 6)
12 - PWM1 / DIO11 (Pin 7)
RSSI PWM Timer. Time RSSI signal will be output after last transmission. When RP =
0xFF, output will always be on.
Commissioning Pushbutton. This command can be used to simulate commissioning button presses in software. The parameter value should be set to the number of button presses to be simulated. For example, sending the ATCB1 command will execute the action associated with 1 commissioning button press. (See D0 command).
CRE
CRE
CRE
0 - 0x1FFF
0 - 0xFF [x 100 ms]
0 - 0x1FFF
0x28 (40d)
Diagnostics
Table 7‐08. Diagnostics Commands
AT
Command
Name and Description
VR
HV
%V
Firmware Version. Read firmware version of the module.
Hardware Version. Read hardware version of the module.
Supply Voltage. Reads the voltage on the Vcc pin. To convert the reading to a mV reading, divide the read value by 1023 and multiply by 1200. A %V reading of 0x8FE
(2302 decimal) represents 2700mV or 2.70V.
1. Node types that support the command:C = Coordinator, R = Router, E = End Device
Node
Type
1
CRE
CRE
Parameter Range Default
0 - 0xFFFF [read-only]
0 - 0xFFFF [read-only]
Factory-set
Factory-set
R -
AT Command Options
Table 7‐09. AT Command Options Commands
AT
Command
Name and Description
CT
2
Command Mode Timeout. Set/Read the period of inactivity (no valid commands received) after which the RF module automatically exits AT Command Mode and returns to Idle Mode.
CN
2
Exit Command Mode. Explicitly exit the module from AT Command Mode.
Node
Type
1
CRE
CRE
Parameter Range Default
2 - 0x028F [x 100 ms]
--
0x64 (100d)
--
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Table 7‐09. AT Command Options Commands
AT
Command
Name and Description
GT
CC
2
2
Guard Times. Set required period of silence before and after the Command Sequence
Characters of the AT Command Mode Sequence (GT + CC + GT). The period of silence is used to prevent inadvertent entrance into AT Command Mode.
Command Sequence Character. Set/Read the ASCII character value to be used between Guard Times of the AT Command Mode Sequence (GT + CC + GT). The AT
Command Mode Sequence enters the RF module into AT Command Mode.
CC command is only applicable when using modules that contain the following “AT
Command” firmware versions: 8.0xx (Coordinator), 8.2xx (Router), 8.4xx (End Device)
Node
Type
1
CRE
CRE
Parameter Range Default
1 - 0x0CE4 [x 1 ms]
(max of 3.3 decimal sec)
0 - 0xFF
0x3E8
(1000d)
0x2B
(‘+’ ASCII)
1. Node types that support the command: C = Coordinator, R = Router, E = End Device
2. Command supported by modules using AT Command firmware only
Sleep Commands
Table 7‐010. Sleep Commands
AT
Command
SM
SN
SP
ST
SO
Command
Name and Description
Sleep Mode Sets the sleep mode on the RF module
Number of Sleep Periods. Sets the number of sleep periods to not assert the On/Sleep pin on wakeup if no RF data is waiting for the end device. This command allows a host application to sleep for an extended time if no RF data is present
Sleep Period. This value determines how long the end device will sleep at a time, up to
28 seconds. (The sleep time can effectively be extended past 28 seconds using the SN command.) On the parent, this value determines how long the parent will buffer a message for the sleeping end device. It should be set at least equal to the longest SP time of any child end device.
Time Before Sleep Sets the time before sleep timer on an end device.The timer is reset each time serial or RF data is received. Once the timer expires, an end device may enter low power operation. Applicable for cyclic sleep end devices only.
Sleep Options. Configure options for sleep. Unused option bits should be set to 0.
Sleep options include:
0x02 - Always wake for ST time
0x04 - Sleep entire SN * SP time
Sleep options should not be used for most applications. See Sleep Mode chapter for more information.
E
CRE
E
E
Node
Type
1
Parameter Range Default
E
0-Sleep disabled
1-Pin sleep enabled
4-Cyclic sleep enabled
Note: When SM=0, the device operates as a router. When SM changes to a non-zero value, the router leaves the network and rejoins as an end device. Only
end devices can sleep
0
1 - 0xFFFF
0x20 - 0xAF0 x 10ms
(Quarter second resolution)
1 - 0xFFFE (x 1ms)
0 - 0xFF
1
0x20
0x1388 (5 seconds)
0
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8. Manufacturing Support
Customizing XBee Default Parameters
Once module parameters are determined, Digi can manufacture modules with specific customerdefined configurations. These custom configurations can lock in a firmware version or set command values when the modules are manufactured, eliminating the need for customers to adjust module parameters on arrival. Contact Digi to create a custom configuration.
XBee EM250 Pin Mappings
The following table shows how the GPIO pins on the EM250 map to pins on the XBee module:
Table 8‐011.
XBee Module Pin Number
10
11
12
13
6
7
8
9
3
4
5
1
2
18
19
20
14
15
16
17
EM250 Pin
Number
-
43
20
25
41
40
-
42
-
32
33
31
13
29
27
26
-
21
19
30
EM250 GPIO
9
10
8
6
5
4
0
-
11
7
-
13
12
3
15
16
-
14
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8
2
9
1
8
2
This figure shows the orientation of the insight port header.
1
9
P in
Num be r
Pin Na m e
1 VB RD
2 SIF-M IS O
3 Ground
4 SIF-M OS I
5 Ground
6 SIF-CLOCK
7 SIF-LOA D
8 RE S ET
9 PTI-E N
10 PTI-DA TA
XBee Custom Bootloader
XBee modules use a modified version of Ember’s boot loader. This bootloader version supports a custom entry mechanism that uses module pins DIN (pin 3), DTR / SLEEP_RQ (pin 9), and RTS (pin
16). To invoke the boot loader, do the following:
1. Set DTR / SLEEP_RQ low (TTL 0V) and RTS high.
2. Send a serial break to the DIN pin and power cycle or reset the module.
3. When the module powers up, DTR / SLEEP_RQ and DIN should be low (TTL 0V) and RTS should be high.
4. Terminate the serial break and send a carriage return at 115200bps to the module.
5. If successful, the module will send the Ember boot loader menu out the DOUT pin at
115200bps.
6. Commands can be sent to the boot loader at 115200bps.
Note: Hardware flow control should be disabled when entering and communicating with the
EM250 bootloader.
Programming XBee Modules
Firmware on the XBee modules can be upgraded using the Digi X-CTU program to interface with the DIN and DOUT serial lines, or with an InSight programmer device via InSight header.
An external application can upload firmware to the XBee modules by doing the following:
1. Enter bootloader mode as described in section 9.4
2. The application should look for the bootloader "BL >" prompt to be sent out the UART to ensure the bootloader is active.
3. Send an ascii "1" to initiate a firmware update.
4. After sending a "1", the EM250 waits for an XModem CRC upload of an .ebl image over the serial line. The .ebl file must be sent to the EM250 in order.
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If no transaction is initiated within 60 seconds, the bootloader times out and returns to the menu.
If the upload is interrupted with a power cycle or reset event, the EM250 will detect an invalid application image and enter bootloader mode. The entire ebl image should be uploaded again to recover. If an error occurs while uploading, the EM250 bootloader returns an error code from the following table:
Table 8‐012.
0x48
0x49
0x4A
0x4B
0x4C
0x4D
0x41
0x42
0x43
0x44
0x45
0x46
0x47
Hex Error Code Description
0x21
0x22
0x23
0x24
0x25
0x26
0x27
The bootloader encountered an error while trying to parse the Start of Header (SOH) character in the XModem frame.
The bootloader detected an invalid checksum in the XModem frame.
The bootloader encountered an error while trying to parse the high byte of the CRC in the
XModem frame.
The bootloader encountered an error while trying to parse the low byte of the CRC in the
XModem frame.
The bootloader encountered an error in the sequence number of the current XModem frame.
The frame that the bootloader was trying to parse was deemed incomplete (some bytes missing or lost).
The bootloader encountered a duplicate of the previous XModem frame.
No .ebl header was received when expected.
Header failed CRC.
File failed CRC.
Unknown tag detected in .ebl image.
Invalid .ebl header signature.
Trying to flash odd number of bytes.
Indexed past end of block buffer.
Attempt to overwrite bootloader flash.
Attempt to overwrite SIMEE flash.
Flash erase failed.
Flash write failed.
End tag CRC wrong length.
Received data before query request/response
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Developing Custom Firmware
Designers can implement custom firmware projects on the XBee module and upload the firmware using X-CTU or one of Ember’s programming tools. The X-CTU can upload firmware onto an XBee as long as the original bootloader is not erased (see section 8.4).
For some applications, it may be necessary to determine if the board is an XBee or an XBee-PRO flavor. The GPIO1 pin is used to identify the module type – it is grounded on the XBee, and unconnected on the XBee-PRO. To determine if a module is an XBee or an XBee-PRO, do the following:
• GPIO_DIRCLRL = GPIO(1); // Set GPIO1 as an input
• GPIO_PUL |= GPIO(1); // Enable GPIO1 pullup resistor
• ModuleIsXBee-Pro = (GPIO_INL & GPIO(1)); // Read GPIO1. If high, XBee-PRO. If low, XBee.
Custom applications should call emberSetTxPowerMode() with the appropriate parameters to configure the RF path correctly.
• Applications running on the XBee should callemberSetTxPower-
Mode(EMBER_TX_POWER_MODE_DEFAULT) or emberSetTxPower-
Mode(EMBER_TX_POWER_MODE_BOOST).
• Applications running on the XBee-PRO should call emberSetTxPower-
Mode(EMBER_TX_POWER_MODE_ALTERNATE) or emberSetTxPower-
Mode(EMBER_TX_POWER_MODE_BOOST_AND_ALTERNATE).
Design Considerations for Digi Drop-in Networking
XBee/XBee-PRO embedded RF modules contain a variety of features that allow for interoperability with Digi's full line of Drop-in Networking products. Interoperability with other "DIN" products can offer these advantages:
• Add IP-connectivity to your network via Cellular, Ethernet or WiFi with a ConnectPort X Gateway.
• Extend the range of your network with the XBee Wall Router.
• Make deployment easy by enabling the Commissioning Pushbutton (pin 20) and Associate
LED (pin 15) to operate with the Network Commissioning Tool software.
• Interface with standard RS-232, USB, Analog & Digital I/O, RS-485, and other industrial devices using XBee Adapters.
• Monitor and manage your network securely from remote locations with Connectware Manager software.
We encourage you to contact our technical representatives for consideration, implementation, or design review of your product for interoperability with Digi's Drop-in Networking solutions.
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Appendix A: Definitions
Definitions
Table A‐01. Terms and Definitions
ZigBee Node Types
Coordinator A node that has the unique function of forming a network. The coordinator is responsible for establishing the operating channel and PAN
ID for an entire network. Once established, the coordinator can form a network by allowing routers and end devices to join to it. Once the network is formed, the coordinator functions like a router (it can participate in routing packets and be a source or destination for data packets).
-- One coordinator per PAN
-- Establishes/Organizes PAN
-- Can route data packets to/from other nodes
-- Can be a data packet source and destination
-- Mains-powered
Refer to the XBee coordinator section for more information.
Router
End device
A node that creates/maintains network information and uses this information to determine the best route for a data packet. A router must join a network before it can allow other routers and end devices to join to it.
A router can participate in routing packets and is intended to be a mains-powered node.
-- Several routers can operate in one PAN
-- Can route data packets to/from other nodes
-- Can be a data packet source and destination
-- Mains-powered
Refer to the XBee router section for more information.
End devices must always interact with their parent to receive or transmit data. (See ‘joining definition.) They are intended to sleep periodically and therefore have no routing capacity.
An end device can be a source or destination for data packets but cannot route packets. End devices can be battery-powered and offer low-power operation.
-- Several end devices can operate in one PAN
-- Can be a data packet source and destination
-- All messages are relayed through a coordinator or router
-- Lower power modes
ZigBee Protocol
PAN Personal Area Network - A data communication network that includes a coordinator and one or more routers/end devices.
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Table A‐01. Terms and Definitions
Joining The process of a node becoming part of a ZigBee PAN. A node becomes part of a network by joining to a coordinator or a router
(that has previously joined to the network). During the process of joining, the node that allowed joining (the parent) assigns a 16-bit address to the joining node (the child).
Network Address
Operating Channel
The 16-bit address assigned to a node after it has joined to another node. The coordinator always has a network address of 0.
The frequency selected for data communications between nodes. The operating channel is selected by the coordinator on power-up.
Energy Scan
Route Request
Route Reply
Route Discovery
ZigBee Stack
A scan of RF channels that detects the amount of energy present on the selected channels. The coordinator uses the energy scan to determine the operating channel.
Broadcast transmission sent by a coordinator or router throughout the network in attempt to establish a route to a destination node.
Unicast transmission sent back to the originator of the route request.
It is initiated by a node when it receives a route request packet and its address matches the Destination Address in the route request packet.
The process of establishing a route to a destination node when one does not exist in the Routing Table. It is based on the AODV (Ad-hoc
On-demand Distance Vector routing) protocol.
ZigBee is a published specification set of high-level communication protocols for use with small, low-power modules. The ZigBee stack provides a layer of network functionality on top of the 802.15.4 specification.
For example, the mesh and routing capabilities available to ZigBee solutions are absent in the 802.15.4 protocol.
© 2008 Digi International, Inc.
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Appendix B: Agency Certifications
United States FCC
The XBee RF Module complies with Part 15 of the FCC rules and regulations. Compliance with the labeling requirements, FCC notices and antenna usage guidelines is required.
To fufill FCC Certification, the OEM must comply with the following regulations:
1.The system integrator must ensure that the text on the external label provided with this device is placed on the outside of the final product. [Figure A-01]
2.XBee RF Module may only be used with antennas that have been tested and approved for use with this module [refer to the antenna tables in this section].
OEM Labeling Requirements
WARNING: The Original Equipment Manufacturer (OEM) must ensure that FCC labeling requirements are met. This includes a clearly visible label on the outside of the final product enclosure that displays the contents shown in the figure below.
Required FCC Label for OEM products containing the XBee RF Module
Contains FCC ID: OUR-XBEE2*
The enclosed device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (i.) this device may not cause harmful interference and (ii.) this device must accept any interference received, including interference that may cause undesired operation.
Required FCC Label for OEM products containing the XBee PRO RF Module
Contains FCC ID:MCQ-XBEEPRO2*
The enclosed device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (i.) this device may not cause harmful interference and (ii.) this device must accept any interference received, including interference that may cause undesired operation.
FCC Notices
IMPORTANT: The XBee and XBee PRO RF Module have been certified by the FCC for use with other products without any further certification (as per FCC section 2.1091). Modifications not expressly approved by Digi could void the user's authority to operate the equipment.
IMPORTANT: OEMs must test final product to comply with unintentional radiators (FCC section
15.107 & 15.109) before declaring compliance of their final product to Part 15 of the FCC Rules.
IMPORTANT: The RF module has been certified for remote and base radio applications. If the module will be used for portable applications, the device must undergo SAR testing.
This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation.
If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures: Re-orient or relocate the receiving antenna, Increase the separation between the equipment and receiver, Connect equipment and receiver to outlets on different circuits, or Consult the dealer or an experienced radio/TV technician for help.
© 2008 Digi International, Inc.
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XBee®/XBee‐PRO® ZB OEM RF Modules
FCC-Approved Antennas (2.4 GHz)
The XBee and XBee-PRO RF Module can be installed utilizing antennas and cables constructed with standard connectors (Type-N, SMA, TNC, etc.) if the installation is performed professionally and according to FCC guidelines. For installations not performed by a professional, non-standard connectors (RPSMA, RPTNC, etc.) must be used.
The modules are FCC approved for fixed base station and mobile applications on channels 0x0B-
0x1A for Xbee Series2 and on channels 0x0B - 0x18 for Xbee ZNet-PRO 2.5 . If the antenna is mounted at least 20cm (8 in.) from nearby persons, the application is considered a mobile application. Antennas not listed in the table must be tested to comply with FCC Section 15.203
(Unique Antenna Connectors) and Section 15.247 (Emissions).
XBee RF Modules: XBee RF Modules have been tested and approved for use with all the antennas listed in the tables below. (Cable-loss IS required when using gain antennas as shown below.)
Table A‐01. antennas approved for use with the XBee RF Modules
YAGI CLASS ANTENNAS
Part Number Type (Description)
A24-Y6NF
A24-Y7NF
A24-Y9NF
A24-Y10NF
A24-Y12NF
A24-Y13NF
A24-Y15NF
A24-Y16NF
A24-Y16RM
A24-Y18NF
Yagi (6-element)
Yagi (7-element)
Yagi (9-element)
Yagi (10-element)
Yagi (12-element)
Yagi (13-element)
Yagi (15-element)
Yagi (16-element)
Yagi (16-element, RPSMA connector)
Yagi (18-element)
OMNI-DIRECTIONAL ANTENNAS
Gain Application*
8.8 dBi Fixed
9.0 dBi Fixed
10.0 dBi Fixed
11.0 dBi Fixed
12.0 dBi Fixed
12.0 dBi Fixed
12.5 dBi Fixed
13.5 dBi Fixed
13.5 dBi Fixed
15.0 dBi Fixed
2 m
2 m
2 m
2 m
2 m
Min. Separation
Required
2 m
2 m
2 m
2 m
2 m
Cable-loss
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Part Number Type (Description)
A24-C1
A24-F2NF
A24-F3NF
A24-F5NF
Surface Mount integral chip
Omni-directional (Fiberglass base station)
Omni-directional (Fiberglass base station)
Omni-directional (Fiberglass base station)
A24-F8NF
A24-F9NF
A24-F10NF
A24-F12NF
A24-F15NF
A24-W7NF
A24-M7NF
Omni-directional (Fiberglass base station)
Omni-directional (Fiberglass base station)
Omni-directional (Fiberglass base station)
Omni-directional (Fiberglass base station)
Omni-directional (Fiberglass base station)
Omni-directional (Base station)
Omni-directional (Mag-mount base station)
PANEL CLASS ANTENNAS
Gain
-1.5 dBi
2.1 dBi
3.0 dBi
5.0 dBi
Application*
Fixed/Mobile
Fixed/Mobile
Fixed/Mobile
Fixed/Mobile
8.0 dBi Fixed
9.5 dBi Fixed
10.0 dBi Fixed
12.0 dBi Fixed
15.0 dBi Fixed
7.2 dBi Fixed
7.2 dBi Fixed
2 m
2 m
2 m
2 m
2 m
2 m
2 m
Min. Separation
Required
20 cm
Cable-loss
N/A
20 cm
N/A
20 cm
N/A
20 cm
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Part Number Type (Description)
A24-P8SF
A24-P8NF
A24-P13NF
A24-P14NF
A24-P15NF
A24-P16NF
A24-P19NF
Flat Panel
Flat Panel
Flat Panel
Flat Panel
Flat Panel
Flat Panel
Flat Panel
Gain Application*
8.5 dBi Fixed
8.5 dBi Fixed
13.0 dBi Fixed
14.0 dBi Fixed
15.0 dBi Fixed
16.0 dBi Fixed
19.0 dBi Fixed
Min. Separation
Required
2 m
2 m
2 m
2 m
2 m
2 m
2m
Cable-loss
N/A
N/A
N/A
N/A
N/A
N/A
1.5 dB
© 2008 Digi International, Inc.
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XBee®/XBee‐PRO® ZB OEM RF Modules
Table A‐02. antennas approved for use with the XBee‐PRO RF Modules
YAGI CLASS ANTENNAS
Part Number Type (Description)
A24-Y6NF
A24-Y7NF
A24-Y9NF
A24-Y10NF
A24-Y12NF
A24-Y13NF
A24-Y15NF
A24-Y16NF
A24-Y16RM
A24-Y18NF
Yagi (6-element)
Yagi (7-element)
Yagi (9-element)
Yagi (10-element)
Yagi (12-element)
Yagi (13-element)
Yagi (15-element)
Yagi (16-element)
Yagi (16-element, RPSMA connector)
Yagi (18-element)
OMNI-DIRECTIONAL ANTENNAS
Gain Application*
8.8 dBi Fixed
9.0 dBi Fixed
10.0 dBi Fixed
11.0 dBi Fixed
12.0 dBi Fixed
12.0 dBi Fixed
12.5 dBi Fixed
13.5 dBi Fixed
13.5 dBi Fixed
15.0 dBi Fixed
2 m
2 m
2 m
2 m
2 m
Min. Separation
Required
2 m
2 m
2 m
2 m
2 m
Cable-loss
7.8dB
8 dB
9 dB
10 dB
11 dB
11 dB
11.5 dB
12.5 dB
12.5 dB
14 dB
Part Number Type (Description)
A24-C1
A24-F2NF
A24-F3NF
A24-F5NF
A24-F8NF
A24-F9NF
A24-F10NF
A24-F12NF
A24-F15NF
A24-W7NF
A24-M7NF
Surface Mount integral chip
Omni-directional (Fiberglass base station)
Omni-directional (Fiberglass base station)
Omni-directional (Fiberglass base station)
Omni-directional (Fiberglass base station)
Omni-directional (Fiberglass base station)
Omni-directional (Fiberglass base station)
Omni-directional (Fiberglass base station)
Omni-directional (Fiberglass base station)
Omni-directional (Base station)
Omni-directional (Mag-mount base station)
PANEL CLASS ANTENNAS
Gain Application*
-1.5dBi Fixed/Mobile
2.1 dBi Fixed/Mobile
3.0 dBi Fixed/Mobile
5.0 dBi Fixed/Mobile
8.0 dBi Fixed
9.5 dBi Fixed
10.0 dBi Fixed
12.0 dBi Fixed
15.0 dBi Fixed
7.2 dBi Fixed
7.2 dBi Fixed
Min. Separation
Required
20 cm
20 cm
20 cm
20 cm
2 m
2 m
2 m
2 m
2 m
2 m
2 m
Cable-loss
-
-
.3 dB
2.3 dB
5.3 dB
6.8 dB
7.3 dB
9.3dB
12.3dB
4.5 dB
4.5 dB
Part Number Type (Description)
A24-P8SF
A24-P8NF
A24-P13NF
A24-P14NF
A24-P15NF
A24-P16NF
A24-P19NF
Flat Panel
Flat Panel
Flat Panel
Flat Panel
Flat Panel
Flat Panel
Flat Panel
Gain Application*
8.5 dBi Fixed
8.5 dBi Fixed
13.0 dBi Fixed
14.0 dBi Fixed
15.0 dBi Fixed
16.0 dBi Fixed
19.0 dBi Fixed
2 m
2 m
2 m
2 m
2m
Min. Separation
Required
2 m
2 m
Cable-loss
8.2 dB
82 dB
12.7 dB
13.7 dB
14.7 dB
15.7 dB
18.7 dB
* If using the RF module in a portable application (For example - If the module is used in a handheld device and the antenna is less than 20cm from the human body when the device is in operation): The integrator is responsible for passing additional SAR (Specific Absorption Rate) testing based on
FCC rules 2.1091 and FCC Guidelines for Human Exposure to Radio Frequency Electromagnetic Fields, OET Bulletin and Supplement C. The testing results will be submitted to the FCC for approval prior to selling the integrated unit.
The required SAR testing measures emissions from the module and how they affect the person.
RF Exposure
WARNING: To satisfy FCC RF exposure requirements for mobile transmitting devices, a separation distance of
20 cm or more should be maintained between the antenna of this device and persons during device operation.
To ensure compliance, operations at closer than this distance are not recommended. The antenna used for this transmitter must not be co-located in conjunction with any other antenna or transmitter.
The preceding statement must be included as a CAUTION statement in OEM product manuals in order to alert users of FCC RF Exposure compliance.
Europe (ETSI)
The XBee RF Module has been certified for use in several European countries. For a complete list, refer to www.digi.com
If the XBee RF Modules are incorporated into a product, the manufacturer must ensure compliance of the final product to the European harmonized EMC and low-voltage/safety standards. A
Declaration of Conformity must be issued for each of these standards and kept on file as described in Annex II of the R&TTE Directive.
© 2008 Digi International, Inc.
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XBee®/XBee‐PRO® ZB OEM RF Modules
Furthermore, the manufacturer must maintain a copy of the XBee user manual documentation and ensure the final product does not exceed the specified power ratings, antenna specifications, and/ or installation requirements as specified in the user manual. If any of these specifications are exceeded in the final product, a submission must be made to a notified body for compliance testing to all required standards.
OEM Labeling Requirements
The 'CE' marking must be affixed to a visible location on the OEM product.
Figure B‐01. CE Labeling Requirements
The CE mark shall consist of the initials "CE" taking the following form:
• If the CE marking is reduced or enlarged, the proportions given in the above graduated drawing must be respected.
• The CE marking must have a height of at least 5mm except where this is not possible on account of the nature of the apparatus.
• The CE marking must be affixed visibly, legibly, and indelibly.
Restrictions
Power Output: The power output of the XBee RF Module must not exceed 10 dBm. The power level is set using the PL command and the PL parameter must equal “0” (10 dBm).
France: France imposes restrictions on the 2.4 GHz band. Go to www.art-telecom.Fr or contact
MaxStream for more information.
Norway: Norway prohibits operation near Ny-Alesund in Svalbard. More information can be found at the Norway Posts and Telecommunications site (www.npt.no).
Declarations of Conformity
Digi has issued Declarations of Conformity for the XBee RF Modules concerning emissions, EMC and safety. Files are located in the 'documentation' folder of the Digi CD.
Important Note
Digi does not list the entire set of standards that must be met for each country. Digi customers assume full responsibility for learning and meeting the required guidelines for each country in their distribution market. For more information relating to European compliance of an OEM product incorporating the XBee RF Module, contact Digi, or refer to the following web sites:
CEPT ERC 70-03E - Technical Requirements, European restrictions and general requirements:
Available at www.ero.dk/.
R&TTE Directive - Equipment requirements, placement on market: Available at www.ero.dk/.
Approved Antennas
When integrating high-gain antennas, European regulations stipulate EIRP power maximums. Use the following guidelines to determine which antennas to design into an application.
XBee OEM Module
The following antennas types have been tested and approved for use with the XBee Module:
Antenna Type: Yagi
RF module was tested and approved with 15 dBi antenna gain with 1 dB cable-loss (EIRP Maimum of 14 dBm). Any Yagi type antenna with 14 dBi gain or less can be used with no cable-loss.
© 2008 Digi International, Inc.
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XBee®/XBee‐PRO® ZB OEM RF Modules
Antenna Type: Omni-Directional
RF module was tested and approved with 15 dBi antenna gain with 1 dB cable-loss (EIRP Maimum of 14 dBm). Any Omni-Directional type antenna with 14 dBi gain or less can be used with no cable-loss.
Antenna Type: Flat Panel
RF module was tested and approved with 19 dBi antenna gain with 4.8 dB cable-loss (EIRP
Maimum of 14.2 dBm). Any Flat Panel type antenna with 14.2 dBi gain or less can be used with no cable-loss.
XBee RF Module
The following antennas have been tested and approved for use with the embedded XBee RF
Module:
- Dipole (2.1 dBi, Omni-directional, Articulated RPSMA, Digi part number A24-HABSM)
- Chip Antenna (-1.5 dBi)
- Attached Monopole Whip (1.5 dBi)
XBee-PRO RF Module
The following antennas have been tested and approved for use with the embedded XBee-PRO RF
Module:
- Dipole (2.1 dBi, Omni-directional, Articulated RPSMA, Digi part number A24-HABSM)
- Chip Antenna (-1.5 dBi)
- Attached Monopole Whip (1.5 dBi).
Canada (IC)
Labeling Requirements
Labeling requirements for Industry Canada are similar to those of the FCC. A clearly visible label on the outside of the final product enclosure must display the following text:
Contains Model XBee Radio, IC: 4214A-XBEE2
The integrator is responsible for its product to comply with IC ICES-003 & FCC Part 15, Sub. B -
Unintentional Radiators. ICES-003 is the same as FCC Part 15 Sub. B and Industry Canada accepts
FCC test report or CISPR 22 test report for compliance with ICES-003.
If it contains an XBee-PRO OEM Module, the clearly visible label on the outside of the final product enclosure must display the following text:
Contains Model XBee PRO Radio, IC: 1846A-XBEEPRO2
The integrator is responsible for its product to comply with IC ICES-003 & FCC Part 15, Sub. B -
Unintentional Radiators. ICES-003 is the same as FCC Part 15 Sub. B and Industry Canada accepts
FCC test report or CISPR 22 test report for compliance with ICES-003.
Transmitters for Detachable Antennas
This device has been designed to operate with the antennas listed in table A-3 and having a maximum of 17.5 dB. Antennas not included in this list or having a gain greater than 17.5 dB are strictly prohibited for use with this device. The required antenna impedance is 50
Ω
Detachable Antenna
To reduce potential radio interference to other users, the antenna type and gained shuold be so chosen that the equivaleny istropically radiated power (e.i.r.p.) is not more than permitted for successful communication
© 2008 Digi International, Inc.
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Appendix C: Migrating from ZNet 2.5 to XBee
ZB
The following paragraph contains the significant differences in XBee ZB compared to its predecessor, ZNet 2.5.
• Command Set
• Firmware Versions
• New Features.
Command Set
The following ZNet 2.5 commands have changed for XBee ZB:
• ID - Set / read the 16-bit PAN ID. This has been replaced by EI - set / read the 64-bit extended PAN ID.
• KY - Set the 128 bit security network encryption key. KY is now only settable on the coordinator. LK must be set on all devices to deploy a very secure network (where the network key is not transmitted in the clear).
• ZA - Set / read the ZigBee Addressing enable command. This command was required in ZNet
2.5 to enable application level addressing commands SE, DE, CI. XBee ZB does not support
ZA. The SE, DE, and CI values always determine the application level addressing values.
• AI - Read the association status. AI now includes several new values.
Firmware Versions
ZNet 2.5 supported coordinator and router/end device targets. Due to flash constraints, XBee ZB split the router/end device target into 2 different targets - router, and end device. There is not a router/end device target.
New Features
ZB offers many new and improved features over ZNet 2.5, including:
• Data transmissions are directly resolved to APS unicasts. This provides the ability to send and receive ZDO commands.
• NH command configures the unicast transmission timeout. This command can extend the number of unicast hops dramatically over the 6-8 hop limit that existed in ZNet 2.5.
• ZS command allows ZigBee stack profile to be set as required.
© 2008 Digi International, Inc.
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Appendix D: XBee ZB Firmware Matrix
Overview of Features
The XBee-ZB firmware supports the following versions:
• 202x - AT Coordinator
• 212x - API Coordinator
• 222x - AT Router
• 232x - API Router
• 282x - AT End Device
• 292x - API End Device.
The supported features of each firmware version are listed in the table below:
Feature
Aggregator Capable
Allows Joining
AT Cmd Mode
API
Channel Verification on
Join (JV)
Commissioning Button
IO Sampling (IS)
Receives unicast traffic from devices in the network
Receives broadcast traffic from devices in the network
Responds to Remote
Commands
Responds to Network
Discovery
RF data transmissions / receptions are always routed through the parent
Routes Data
202x
(AT
Crd)
X
X
X
X
X
X
X
X
X
212x
(API
Crd)
X
X
222x
(AT
Rtr)
X
X
X
X
X
X
X
X
X
X
X
X
X
232x
(API
Rtr)
X
X
282x
(AT End-
Dev)
X
X
X
292x
(API End-
Dev)
X
X
X
X X X
X
X
X
X
X
X
X
X
X
X
X
X
**
X
X
X
**
X
X
X
© 2008 Digi International, Inc.
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XBee®/XBee‐PRO® ZB OEM RF Modules
Sends Network
Discovery (ND)
Sends Network Reset
(NR1)
Sends Remote
Commands
Sleep Modes
X
X
X
X
X
X
X
X
X
X
X
X
X
© 2008 Digi International, Inc.
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Appendix E: : Additional Information
1-Year Warranty
XBee RF Modules from Digi, Inc. (the "Product") are warranted against defects in materials and workmanship under normal use, for a period of 1-year from the date of purchase. In the event of a product failure due to materials or workmanship, Digi will repair or replace the defective product.
For warranty service, return the defective product to MaxStream, shipping prepaid, for prompt repair or replacement.
The foregoing sets forth the full extent of MaxStream's warranties regarding the Product. Repair or replacement at MaxStream's option is the exclusive remedy. THIS WARRANTY IS GIVEN IN LIEU
OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, AND DIGI SPECIFICALLY DISCLAIMS ALL
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
SHALL DIGI, ITS SUPPLIERS OR LICENSORS BE LIABLE FOR DAMAGES IN EXCESS OF THE
PURCHASE PRICE OF THE PRODUCT, FOR ANY LOSS OF USE, LOSS OF TIME, INCONVENIENCE,
COMMERCIAL LOSS, LOST PROFITS OR SAVINGS, OR OTHER INCIDENTAL, SPECIAL OR
CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PRODUCT, TO
THE FULL EXTENT SUCH MAY BE DISCLAIMED BY LAW. SOME STATES DO NOT ALLOW THE
EXCLUSION OR LIMITATION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES. THEREFORE, THE
FOREGOING EXCLUSIONS MAY NOT APPLY IN ALL CASES. This warranty provides specific legal rights. Other rights which vary from state to state may also apply.
Contact Digi
Free and unlimited technical support is included with every Digi Radio Modem sold. For the best in wireless data solutions and support, please use the following resources:
Technical Support: Phone.
(866) 765-9885 toll-free U.S.A. & Canada
(801) 765-9885 Worldwide
Live Chat. www.digi.com
Digi’s office hours are 8:00 am - 5:00 pm [U.S. Mountain Time]
© 2008 Digi International, Inc.
98
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