DATA SHEET

DATA SHEET
Remote control & communications
Order code
82-4094
Manufacturer code
n/a
Description
RF600T TRANCEIVER IC (RC)
Remote control & communications
The enclosed information is believed to be correct, Information may change ‘without notice’ due to
product improvement. Users should ensure that the product is suitable for their use. E. & O. E.
Sales: 01206 751166
Sales@rapidelec.co.uk
Technical: 01206 835555
Tech@rapidelec.co.uk
Page 1 of 14
Revision A
04/07/2003
Fax: 01206 7551188
www.rapidelectronics.co.uk
Smart Com Radio Transceiver IC
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•
RF600T
Enables Easy Radio Communications
Connects directly to RF Module
Simple CMOS/TTL Data Interface
Performs all Data Encryption for Reliable Data Comms.
Addressed Mode With Acknowledge
Broadcast Mode
Automatic Retry
Achieves Maximum Range From RF Modules
Optional host Flow Control
Two Telemetry I/O Lines (addressed mode only)
Compatible With Most RF Modules
Typical Applications
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Wireless RS232
Cable Replacement
Alarm Systems
Communications Systems
1
OUT2
18
Local Area Networking
2
CTS
OUT1
17
3
LEARN
OSC1
16
4
RTS
OSC2
15
5
GND
6
MODE
190 Byte data Buffer
‘Manchester’ Modulation
CRC Error Checking
9
Hardware Features
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3.0 – 5.5V Operation. (2.0 – 5.5V optional)
RxR
RF600T
Vcc
14
IN2
13
7
TxH
IN1
12
8
RxH
RxEN
11
TxR
TxEN
10
18 pin DIP/SOIC Package
2 Digital Telemetry Lines (addressed mode only)
Asynchronous Serial Host Interface
The RF600T provides a simple interface between TTL level asynchronous serial data sources and standard
RF modules (Transceiver, Transmitter or Receiver) with minimal interface required.
The RF600T performs all the necessary data manipulation and encryption required by the Radio module to
achieve a reliable radio link whilst providing a simple data interface to the users controller.
The device has been designed to obtain the maximum range from the Radio medium using automatic data
packet generation with ‘Manchester’ encoding and CRC based error checking. In addition, in addressed
mode, automatic retries ensure that the host is informed of successful or failed data packet delivery. The
RF600T uses control lines to handle the flow of data to and from the host, and incorporates a 190 byte data
buffer.
DS601-4
Part Number
RF600T
Description
Transceiver IC PDIP Package
Package
18pin PDIP
RF600T-SO
Transceiver IC SMT Package
18pin SO
RF600T-EVAL
Evaluation Kit for Smart Radio Modules
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Smart Com Radio Transceiver IC
RF600T
Pin Descriptions
Pin
Number
Name
Type
1
RxR
In
2
CTS
LOOP
Out
In
3
LEARN
In/Out
4
5
6
7
8
RTS
GND
MODE
TxH
RxH
In
In
In
In
Out
9
TxR
HBAUD
Out
In
10
TXEN
RFBAUD
Out
In
11
12
13
14
15
16
17
18
RXEN
IN1
IN2
Vcc
OSC2
OSC1
OUT1
OUT2
Out
In
In
In
Out
In
Out
Out
Description
Received data from RF module.
Dual Function:
1. Clear to send data (to host) when low.
2. Enables loopback mode when low.
In addressed mode: Used to initiate ‘address learn’ and erase
functions. Drives indicator LED.
Request to send data (from host) when low.
Connect to 0 volts.
Device mode, addressed when high, broadcast when low.
Serial data from the host, to be sent on the RF path.
Serial data from the RF path to be sent to the host.
Dual Function:
1. Transmit data to the RF module.
2. Host baud rate select. See notes below.
Dual Function:
1. Transmit enable (low) for the RF module.
2. RF baud rate select. See notes below.
Receive enable (low) for the RF module.
Telemetry logic input #1. (addressed mode only)
Telemetry logic input #2. (addressed mode only)
Positive supply voltage connection.
Connect to 4MHz, 3 terminal resonator.
Connect to 4MHz, 3 terminal resonator.
Telemetry logic output #1. (addressed mode only)
Telemetry logic output #2. (addressed mode only)
Operating Modes
The device is capable of operation in one of two modes, either broadcast or addressed. The following description
describes the features of these mode and assumes two identical system nodes ‘A’ and ‘B’ each consisting of an
RF600T and its associated radio transceiver module.
The RF600T must be configured before power up for either the broadcast or addressed mode of operation by
means of the MODE pin (6). Note that for security, broadcast nodes will not receive data from addressed nodes.
Broadcast mode.
This mode allows a host generated data block from node ‘A’ to be transmitted and received by any number of
other nodes. This data is received and verified (for correct Manchester coding and CRC) by the other nodes before
being output to their host devices. Alternately, in the same way the other nodes can send data to node ‘A’. Note
that although any node can initiate a transfer, only one direction of transfer can be active at a given time.
Correct reception of a data packet is not acknowledged and the host nodes have the responsibility of ensuring that
data transfers occur as required by operating some form of message protocol over the half duplex data link.
Addressed mode
This mode allows a host generated data block from node ‘A’ to be transmitted and for the data frame to be
addressed to one other network node – in this case we assume node ‘B’. When the data is received by node ‘B’ it
is verified for correct Manchester coding, CRC and for address match and then an acknowledge message is
transmitted back to node ‘A’. Node ‘A’ then outputs a confirmation to the host in the form of the ASCII character ‘C’
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Smart Com Radio Transceiver IC
RF600T
(Confirmed). Note that confirmation is given when the data block is stored in the buffer of node ‘B’ and not when it
has been delivered to the host at node ‘B’.
All message transfers are tagged with the addresses of both the origin and destination, thus ensuring secure data
transfer at all times. Either node ‘A’ or node ‘B’ can initiate a transfer but only one direction of transfer can be
active at a given time. In the event that the originating node does not get confirmation of receipt of the data packet,
the software re-tries the transfer five times after which node ‘A’ will output an error message to the host in the form
of the ASCII character ‘F’ (Failed).
Correct reception (or otherwise) of a data packet is thus acknowledged and the host devices are relieved of most of
the workload of ensuring that data transfers occur as required.
System Operation – Broadcast Mode
If operation in the broadcast mode is required then on power up the MODE pin should be pulled low. If however a
device has been used in the point to point addressed mode or if its status is unknown then status erase must be
carried out using the following procedure. With the unit in addressed mode (power up with MODE low) the LEARN
pin is grounded for a period of 5 seconds and is then allowed to float. The status LED then flashes slowly for 3
seconds to indicate that the device is erased.
System Operation – Addressed Mode
Each RF600T is programmed at manufacture with a 24 bit serial number which uniquely identifies the device. In an
addressed point to point system, these serial numbers are used as the device address for the nodes in the system
and non-volatile eeprom memory in the device stores the address of the ‘other’ node in the system.
If operation in the addressed mode is required then the following procedure has to be followed to allow the two
nodes in the system to operate together.
The two nodes, ‘A’ and ‘B’ are placed within radio range of one another are powered up with the MODE
pin held high.
The LEARN pin on one device – say ‘B’ is briefly taken low, placing the node into learn mode. The
LEARN/ERASE status LED on ‘B’ comes on and remains on for 20 seconds. If within this period, no
‘learn’ data packet is received (see below) then the LED will be extinguished and the device will operate
normally.
At node ‘A’, the LEARN pin is briefly taken low. The LEARN/ERASE status LED will then come on and
node ‘A’ will transmit its address.
Node ‘B’ will receive and store the address of ’A’.
Node ‘B’ sends back to node ‘A’ both its address and that of node ‘A’.
Node ‘A’ receives and stores the address of ’B’ and confirms to ‘B’ that it has received the information.
Both node ‘A’ and ‘B’ LED's flash their status LED’s rapidly for 3 seconds to show that they have
learned each others addresses.
Note: Other nodes which may be active will ignore this transfer since they have not been placed into
learn mode.
If notification of correct reception (or otherwise) of data packets is required but it is not possible or desirable to
carry out the learn process then a modified addressed mode of operation may be implemented. In this mode, both
nodes have their eeprom memory erased using the erase process, thus placing null serial numbers ($000000) for
the ‘other’ node into both device eeproms. If the devices are now employed in addressed mode (power up with
MODE pin high) they will operate as if they had learned one another’s identity using the normal learn process. Note
that in this mode, only two device may be employed within range of one another since data transfer is effectively
carried out as a broadcast to all nodes with a null address.
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Smart Com Radio Transceiver IC
RF600T
Dual Pin Functions
As shown in the pin function list above, a number of output pins have dual usage. During power up
they are briefly configured as inputs to allow the selection of system options as shown below. Note
that any load connected to these pins must not bias the RF600T pin such that the option setting
network is significantly disturbed.
In order to configure these pins it is recommended that they are connected as shown.
Vcc or GND
1. Tie the relevant pin to Vcc or GND via
a 100K resistor. This is useful if the
option is permanently unselected.
2. Tie to Vcc or GND via a 100K resistor
and also add a jumper link and 2.2K
resistor to the other rail. This allows the
user to select the function of the pin by
insertion/removal of the link.
Pin
Number
Name
100KΩ
RF600T
Pin
Type
LOOP
In
CTS
Out
3
HBAUD
In
TxR
Out
RFBAUD
In
TXEN
Out
9
10
Vcc
100KΩ
RF600T
Pin
2.2KΩ
Description
Function during power up:
Sets RF600T into ‘Loop back’ Mode (see below)
Disabled if connected to Vcc as shown above.
Enabled if connected to GND as shown above.
Function after power on:
Clear To Send control line to host (when low).
Function during power up:
Host Baud rate Select.
9600baud if connected to Vcc as shown above.
19200baud if connected to GND as shown above.
Function after power on:
Transmit data to radio module..
Function during power up:
Controls the baud rate for the RF link.
400uS if connected to Vcc as shown above.
200uS if connected to GND as shown above.
Function after power on:
Transmit enable (low) to radio module.
Learn pin (addressed mode only)
The learn pin is used both to sense the learn/erase switch and also to drive the indicator LED and should
be connected as shown in the application circuit. The switch, which should be of the normally open type,
should be connected from the learn pin to ground. The LED and its series current limiting resistor should
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Smart Com Radio Transceiver IC
RF600T
be connected from Vcc to the learn pin, ensuring that the maximum current drawn by the LED (as given in
this data sheet) is not exceeded.
Data Buffering
The device contains a 190 byte data buffer which is used to either buffer host data prior to transmission
over the radio link or alternately to buffer data received over the radio link before it is transmitted to the
host. Since this is a shared buffer the device can only operate in a half duplex manner - that is at a given
time data can either be received from the host and then transmitted over the radio link or data can be
received over the radio link and sent to the host but these functions cannot occur at the same time. Once
a character has been received from the host or once the start of a radio data packet has been sensed the
device will lock out the ‘other’ function until the first one has been completed.
Host Interface
The interface to the host device consists of the following signal and control lines:
TxH
Serial data from the host which is to be transmitted over the RF link. Idle mark ‘1’.
RxH
Serial data for the host which has been received over the RF link. Idle mark ‘1’.
CTS
Handshake line to the host. When ‘0’ tells the host that it is Clear To Send data to the RF600T for
transmission over the RF link.
RTS
Handshake line from the host. When ‘0’ tells the RF600T that the host is making a Request To
Send data to the host.
Host Communications
All host communications are carried out using the following asynchronous serial format.
8 data bits.
1 stop bit.
No parity.
The host baud rate is selected using the HBAUD option as described above.
Host Data Flow Control
Serial data from the host which is to be sent over the radio link is input at TTL level on the TxH pin. When
the device is ready to receive data, the CTS line from the device will be low and up to 190 data bytes will
be accepted and stored in the internal data buffer. When the buffer becomes full the CTS line will be taken
high and the host must then stop transmitting. In order to allow for host UART’s which have an output
FIFO buffer, a further 4 characters will be accepted after the CTS line has been asserted. In the event that
the flow of data characters is not contiguous and an idle period of 20 ms occurs in the data stream then
the CTS line will be asserted high to signify that the host should stop sending further data. In this case the
current buffer contents will make up the next data packet to be sent over the radio link.
Serial data which has been received over the radio link will be checked for correct Manchester coding and
CRC checksum (and address match if in addressed mode) before this data is transmitted at TTL level on
the RxH pin. Data flow to the host is controlled by the RTS line from the host. When this line is low, data in
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Smart Com Radio Transceiver IC
RF600T
the buffer will be transmitted to the host. When the RTS line is taken high then data flow will be inhibited
and until the buffer is empty the device will not be able to perform any other operations.
Packet Size and Timing
The following information is provided to aid in timing calculations for the RF data transmission.
Element
Run-In / Pre-amble
Sync Pattern
Start Bit
Command Byte
Source Address
Destination Address
Data Bytes
Checksum
Size (bits)
76
4
1
8
32
32
xxx
8
Modes Present
Both
Both
Both
Both
Addressed only
Addressed only
Both
Both
Addressed mode packet overhead:
POa = 76+4+1+8+32+32+8 = 161 bits
Addressed Transmission time, presuming 200uS element time, no idle period:
TTa = 200uS x (POa + No. Data Bits)
Please note this timing is for RF transmission only the RS232 communications timing is not included.
Radio Module Interface
The interface to the radio module(s) consists of the following signal and control lines:
TxR
Serial data output from the RF600T to the radio module.
RxR
Serial Data input to the RF600T from the radio module.
TXEN
When active low the RF Transmitter is enabled
RXEN
When active low the RF Receiver is enabled
Radio Module Communications
All data communications between the radio modules are carried out using an R. F. Solutions proprietary
data protocol with Manchester coding. This protocol includes a pre-amble and synchronisation header
followed by address and control bytes, data and a CRC check. Element timing is selectable at either 400
us or 200 us using the HBAUD option as described above.
Radio Module Control
The RXEN and TXEN control lines are used to enable or disable the receiver and transmitter modules – or
in the case of a transceiver module, to control the direction of operation. The logic of these outputs is such
that when the RF600T wishes to transmit, it will take the RXEN line high and the TXEN line low. When the
RF600T wishes to receive, it will take the RXEN line low and the TXEN line high.
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Smart Com Radio Transceiver IC
RF600T
Digital Telemetry Lines (addressed mode only)
In addressed mode, two input pins have their state monitored at all times and when either changes state
the new states will be transmitted and applied to the outputs at the other nodes. If system is idle this
information will be transmitted as part of a ‘dummy’ data packet, which contains no data. If the system is
transferring data then the telemetry information is added in the command byte of the next transmitted data
packet.
Some care is required in using the logic pins as shown in the following notes.
1. The acknowledge and retry functions are not applied to these transmissions
2. If host data is being transmitted to the device when the logic input pins change state then
the new state will not be transmitted until the current host data packet is sent. (The data
packet is sent according to the flow control rules)
Loop Mode
Loop mode is provided to allow testing of the performance of a system and allows node ‘A’ to transmit a
data packet which will be looped back by node ‘B’ and received by node ‘A’. The mode settings of the
nodes are ignored in the loop mode and the transfer is carried out in broadcast mode. The mode must
only be selected when there are just two nodes in a network.
If we assume that we wish to send a host data packet from node ‘A’ to node ‘B’ and have the packet
returned such that host ‘A’ receives back its data packet then the LOOP link in node ‘A’ should be made
before that unit is powered up. This unit will now only operate in the loop mode until it is powered down,
the loop link removed and then powered up again.
Note that the learn function will not operate when the system is configured for loop mode.
System Testing
Testing of a prototype system can best be carried out using two PC’s running HyperTerminal with the
properties set as follows. (options not listed can be left in default state)
Connect to:
direct to COM1 or COM2
Configure (port settings):
Baud rate: 9600 or 19200 depending on RF600T setting.
Data bits: 8
Parity: none
Stop bits: 1
Flow control: hardware
Settings:
Emulation: TTY
Note that addressed mode file transfers should be tested using the drop down menu option: ‘Transfer –
Send Text File’ and NOT the ‘Transfer – Send File’ option since this latter employs modem transfer
protocols such as Xmodem and Kermit which will be confused by the ‘C’ and ‘F’ responses sent back from
the RF600T.
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Smart Com Radio Transceiver IC
RF600T
Application Circuit
The circuit shown below is for a typical RF600T application. A 9 way ‘D’ connector provides an RS232
termination to the host system and the RXQ1 hybrid contains all of the circuitry required to implement the
RF path. In many applications it will be possible to dispense with the option links and hard-wire the options
to the desired settings. Note however that the host and RF baud options and loop option must be set using
resistors as described above.
RF600T Application Circuit with RXQ1 Transceiver and RS232 Interface.
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Smart Com Radio Transceiver IC
RF600T
RF600T application circuit – minimum implementation.
This circuit shows the minimum implementation of the RF600T. Two such circuits should be constructed
with RXDATA_RF connected to TXDATA_RF (that is the RF data paths are crossed over). Data input on
the TXDATA_HOST input of one RF600T will then appear on the RXDATA_HOST pin of the other
RF600T. Note that in this circuit the host data rate is fixed at 9600 bauds and the ‘RF’ data element time is
400 us. Either broadcast or addressed modes may be used depending on the setting of the option link.
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Smart Com Radio Transceiver IC
RF600T
Smart Radio Evaluation Kit
The Smart Radio Evaluation Kit provides a hardware platform to enable
fast development of Radio applications.
Supplied as a pair of boards, each can accept a variety of RF Modules
including transmitters, receivers and transceivers, an RS232 port is
incorporated for direct connection to a PC.
The boards may be used for a wide range of tasks from simple RS232
data transmission to integrated system development and is the ideal
platform for exploring the advantages of using the “Smart Comms” range
of ICs and radio modules.
This eliminates the need to construct hand-wired prototype boards, which
are rarely successful in creating a valid environment for the development
of radio systems. (prototyping board also contains large stray capacitance
values which has a detrimental effect on the RF connections).
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Hardware Platform for Radio Comms Development
Accepts Various RF Modules
RS232 Interface to PC
Supplied with RF600T Smart Comms Controller
Performs all Data Encryption for Reliable Data Comms.
Two Telemetry I/O Lines (addressed mode only)
Range Testing
Contents
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Two Eval Boards
Two RF600T Comms Controllers
Circuit diagrams
Two RS232 PC cables
Radio Modules and Antenna available
Separately.
Target Environment Testing
Antenna Evaluation
Achieving Optimum Range
Range is dependant on many factors including
1. RF Power output
2. Receiver sensitivity
3. Antenna efficiency
4. Local environmental conditions and any local Interference
5. Data Type which is being transmitted.
Whilst items 1-4 are dependant on the system hardware design, item ‘5’ is equally important and often
overlooked. Given that there is a legal maximum power output which can be transmitted, and a limit on the
sensitivity of the receiver (usually constrained by cost), and that the antenna can never achieve 0dB loss
(100% efficiency), then the data structure and coding is an important aspect of the design.
The RF600T uses a fully balanced Manchester encoded data protocol designed for optimum use of the
radio transmission path. Manchester encoding enables the receiver ‘data slicer’ to maintain efficiency for
the duration of the data packet, (unlike many other encoder/decoder systems) which results in reduced bit
errors and therefore ensures maximum range.
Custom Versions
Customisation of the RF600T is available, please contact our sales department for further information.
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Smart Com Radio Transceiver IC
RF600T
Technical Specifications: Absolute Maximum Ratings
Item
Rating
Supply voltage
Units
-0.3 to 6.9
V
Input voltage
-0.3 to VDD + 0.3
V
Output voltage
-0.3 to VDD+ 0.3
V
25
mA
Storage temperature
-55 to +125
°C (Note)
Lead soldering temp
300
°C (Note)
ESD rating
4000
V
Max output current
Note: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device.
Electrical Characteristics
Min
Operating current (average)
Vdd = 2 - 3V
Vdd = 3 - 6.6V
Typical
Max
Unit
0.3
0.7
1.2
1.6
mA
High level Input voltage
0.55VDD
VDD+0.3
V
Low level input voltage
0.3
0.15VDD
V
0.08VDD
V
High level output voltage
V
0.7VDD
Low level output voltage
Output Pin Current rating
LED sink current
DS601-4
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-
25
mA
5.0
25
mA
©2004 Reg. No. 227 4001, ENGLAND
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Smart Com Radio Transceiver IC
DS601-4
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RF600T
Page 12
Smart Com Radio Transceiver IC
RF600T
R. F. Solutions Ltd.,
Unit 21, Cliffe Industrial Estate,
Lewes, E Sussex, BN8 6JL, England
Tel +44 (0)1273 898 000
Fax +44 (0)1273 480 661
Email sales@rfsolutions.co.uk
http://www.rfsolutions.co.uk
R F Solutions is a member of the Low Power Radio Association.
All Trademarks acknowledged and remain the property of the respected owners.
Information contained in this document is believed to be accurate, however no representation or warranty is given and R.F. Solutions Ltd. assumes no liability with respect to the accuracy of such
information. Use of R.F. Solutions as critical components in life support systems is not authorised except with express written approval from R. F. Solutions Ltd.
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