1
Introduction
User Guide
Modbus Communications for PanelView Terminals
This document describes how to connect and configure communications for the Modbus versions of the PanelView terminals.
This document provides supplemental information for the
PanelBuilder32 manuals.
For more information about:
Related Publications
Before using this Guide
Modbus Protocol
Modbus PanelView Terminals
Typical Modbus Network
Connector Pinout Definitions
Serial Port Connection
Modifying Modbus Settings from Terminal
Setting up Communications using PanelBuilder32
Modbus Address Spaces
Modbus Controller Data Table
Data Formats
Tag Editor
Downloading Applications over a Serial Link
Error Messages and Codes
Glossary
15
16
16
19
8
9
11
14
20
24
4
7
3
3
Go to page:
2
2
Publication 2711-6.9
2 Modbus Communications for PanelView Terminals
Related publications
The following documentation provides additional information on installing, configuring and using your PanelView terminals.
Publication Titles
PanelBuilder32 Getting Results Manual
PanelBuilder32 Quick Start Manual
PanelView Operator Terminal Manual
Number
2711-6.19
2711-6.20
2711-6.1
The Modicon website provides information and product descriptions of Modbus products at:
www.modicon.com
Before using this guide
We assume that you are familiar with Modbus communications. Since we cannot provide specific information about every type of application the PanelView might be used in, the information provided in this document is general, rather than specific.
Refer to glossary at the end of this publication for definitions of unfamiliar terms.
Publication 2711-6.9 - March 2000
Modbus protocol
Modbus PanelView
Terminals
Modbus Communications for PanelView Terminals 3
Modbus protocol links Modicon Programmable Controllers and devices emulating Modicon Programmable Controllers in a wide variety of applications. Modbus protocol defines a message structure that controllers can use regardless of the network type over which they communicate.
Modbus is a half-duplex, master-slave communications protocol. The network master (PanelView) reads and writes coils and registers as if it was a Modicon controller. Every device on a Modbus communication link emulates the coils and registers of a Modicon Programmable
Controller. Modbus allows a host to read and write coils/registers and obtain diagnostic information.
Modbus protocol allows a single master to communicate with a maximum of 255 slave devices. The master device on a Modbus network is not assigned an address.
Modbus terminals are identified by a 14 at the end of the catalog number, for example 2711-K9C14.
The Modbus terminals have:
•
Modbus communication port
•
RS-232 printer/file transfer port
In addition, each terminal is available with either:
•
AC or DC power
The characters L1 at the end of the catalog number designate a terminal with DC power (e.g. -T9A14L1).
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4 Modbus Communications for PanelView Terminals
Typical Modbus Network
Shown below is a typical Modbus network with Modbus Controllers installed on two of the network drops.
PanelView
Master Device
(1 per Network)
Modbus Port
RS-485/422
RS-232 Port
Computer for developing
PanelView applications
Serial Link or
Printer
Modbus Programmable Controller or Device Emulating a Controller
(Slave Device)
Modbus Programmable Controller or Device Emulating a Controller
(Slave Device)
Modbus +
Publication 2711-6.9 - March 2000
Modbus Communications for PanelView Terminals 5
Connection to a Modbus
Plus Network
Using a Bridge Multiplexer (BM85) or an RF modem, the Modbus
PanelView can be connected to a Modbus Plus network.
Modbus Plus is a local area network supporting up to 64 nodes at a data transfer rate of 1,000,000 bits/second. Modbus Plus provides host level peer-to-peer communication for network devices. The network also provides distributed input/output (DIO) communications.
The BM85 Bridge Multiplexer provides connection to a Modbus Plus network through the PanelView Modbus RS-232 serial port.
Modbus
RS-232
Port
PanelView
B M
85
Modbus +
Bridge Multiplexer
Cable - PanelView to BM85
PanelView
BM85
2
3
5
5
6
7
8
9
3
2
4
PanelView
Modbus
RS-232
Port
RF
Modem
RF
Modem
Modbus +
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6 Modbus Communications for PanelView Terminals
Making Modbus
Connections
The PanelView Modbus protocol communicates with other devices over an RS-232 (point-to-point) or RS-485/RS-422 (multi-drop) serial link. Refer to the following pinout information to connect the
PanelView to a Modbus network.
Important: Follow the Modbus network layout and design as specified by the user manual for your programmable controller.
PanelView
Line Termination
DIP Switch for RS-485/422
1 2
OFF
ON
Not Used
OFF = termination is off
ON = line terminated
PanelView Modbus Connector
5
1
9
6
Refer to next page for a description of pinout connections.
Line Termination
The device at each end of an RS-485/422 network should be terminated. A termination switch is provided on the PanelView (see figure above). Enabling line termination provides an RC line termination of .01mF and 120
Ω
.
Do not use line termination for RS-232 communications. Do not terminate devices between the network ends.
ATTENTION
!
Use a nonconducting probe to change the line termination switch. Do not use a graphite pencil or other conductive material. Failure to use a nonconducting tool, may result in damage to the
PanelView.
Publication 2711-6.9 - March 2000
Connector Pinout
Definitions
Modbus Communications for PanelView Terminals 7
The communication type is downloaded with an application or is set on the terminal configuration screen. The PanelView supports RS-232,
RS-485 and RS-422 communication standards. The Modbus 9-pin male
D shell connector has the following pin definitions for each standard.
7
8
5
6
9
Pin
Number
1
2
3
4
Function
RS-232 RS-485/RS-422
Shield
RXD
TXD
DTR
COMMON
DSR
RTS
CTS
No Connection
Shield
RXD
TXD
See note
3
COMMON
See note
TXD
RXD
1 ,2
1,2
3
No Connection
1. In RS-485 mode, pin 2 and pin 3 require an external jumper to electrically connect pins 2 and 3.
2. In RS-485 mode, pin 7 and 8 require an external jumper to electrically connect pins 7 and 8.
3. These pins must remain unconnected.
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8 Modbus Communications for PanelView Terminals
Making Serial Port
Connections
PanelView
Use the RS-232 serial port on the PanelView terminal to:
• download/upload applications over a serial link
• or to connect a printer
Computer
COMM 1 or 2
5 1
RS-232 Printer/
File Transfer Port
9
6
6
7
4
5
9-pin female
1
2
3
8
9
Available Cables
2711-NC13 5 m (16.4 ft)
2711-NC14
10 m (32.7 ft)
2706-NC13
3 m (10 ft)
9 to 25 Pin Adapter
(if required)
9-pin male
1
2
3
6
7
4
5
8
9
RS-232
Port
Printer
PV550 Printer Port (DCE)
9-pin male
COM
6
7
4
5
8
9
PV300/600/900/1000/1400 Printer Port (DCE)
9-pin male
1
2
3
NC
RXD or TR1 (Data Receive)
TXD or TX1 (Data Transmit)
NC
COM
DSR (pulled high to +12V)
RTS or RX2 (Data Receive)
CTS or TX2 (Data Transmit)
NC
Printer/Computer Port (DTE)
9-pin female
8
9
6
7
4
5
2
3
1
DCD
RXD (Data Receive)
TXD (Data Transmit)
DTR
COM
DSR
RTS
CTS
NC
Upload/Download or Printer Cable without Hardware Handshaking
PV550 Printer Port (DCE)
9-pin male
2
RXD or RX1 (Data Receive)
3 TXD or TX1 (Data Transmit)
5 COM
Printer/Computer Port (DTE)
9-pin 25-pin
2
3
5
3
2
7
RXD (Data Receive)
TXD (Data Transmit)
TXD COM
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Modbus Communications for PanelView Terminals 9
Modifying Modbus Settings from the Terminal
You can display or modify Modbus settings directly from the terminal. From the
Configuration Mode menu of the terminal, select Serial Communication Setup. The screen below appears.
ATTENTION
!
Settings downloaded with a Modbus application have priority over terminal settings. Modbus settings take effect immediately after an application is downloaded.
MODBUS RTU MASTER
#############
Baud:
Data Bits/Parity:
Response Timeout (ms):
9600
8/Odd
####
Port/Modem Handshake: Modem
#### RTS TX Delay (ms):
RTS Off Delay (ms):
CTS Timeout (ms):
####
####
Restart
Terminal
Error - ##
###
Exit
Reset Terminal [F1]
Resets the terminal.
Baud Rate [F2]
Steps through the available baud rates: 300, 1200, 4800, 9600, 19200,
28800, and 38400 with each key (or screen) press. A selected baud rate takes effect immediately.
Parity/Data Bits [F3]
Steps through the available options:
•
8 EVEN
•
8 ODD
•
8 NONE (Default Setting)
Note: All communications occur with 1 stop bit.
Response Timeout (ms) [F4]
Opens the numeric entry scratchpad. Provide a timeout value of 20 to
5000 milliseconds. The timeout specifies the time, after a command is sent by the PanelView terminal, that an error is indicated by no response from the slave device.
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10 Modbus Communications for PanelView Terminals
Port/Modem Handshake [F5]
Steps through the available options:
•
MODEM
•
RS-232
•
RS-422
•
RS-485
Note: The following delays (RTS TX, RTS Off, and CTS Timeout) facilitate modem communications. Refer to your modem user manual for information on the recommended delay values.
RTS TX Delay (ms) [F6]
Opens the numeric entry scratchpad. Provide a delay value of 0 to
2000 milliseconds. The RTS TX delay specifies the delay between the assertion of the RTS signal and the transmission of the first character of the Modbus message.
RTS Off Delay (ms) [F7]
Opens the numeric entry scratchpad. Provide a delay value of 0 to
2000 milliseconds. The RTS Off delay specifies the delay between the transmission of the last character of the Modbus message and the assertion of the RTS signal.
CTS Timeout (ms) [F8]
Opens the numeric entry scratchpad. Provide a timeout between 0 to
2000 milliseconds. The CTS timeout specifies the maximum allowable delay between the assertion of the RTS signal by the PanelView terminal and the assertion of the CTS signal by the modem.
Exit [F10] or [F16]
Returns to the Configuration Mode menu.
Publication 2711-6.9 - March 2000
Modbus Communications for PanelView Terminals 11
Setting up Communications
Setting up Modbus communications for an application includes:
• selecting a Modbus terminal when creating the application.
• configuring communication parameters for the terminal on the
Modbus link.
Selecting a Modbus PanelView Terminal
Select a Modbus terminal for a PanelView application from:
•
Create New Application dialog or the
•
Terminal Setup tab of the Application Settings dialog when converting the application to run in another terminal.
Any catalog number with 14 as the last number (2711-xx14) is a
Modbus terminal.
Indicates RS-232 port is set for downloading applications not printing
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12 Modbus Communications for PanelView Terminals
Configuring Modbus Communications
Modbus communication parameters are accessed from the Terminal Setup dialog.
To open the Terminal Setup dialog, choose Terminal Setup from the
PanelBuilder32 Application menu.
If RS232, RS422, or RS422 Port Configuration is selected
Publication 2711-6.9 - March 2000
If Modem Handshaking is selected
1. Click the Comms. Setup button from the Terminal Setup dialog.
2. Under Network Devices, edit the following parameters:
Specify:
Node Name
Node Address
Type
To:
Either select a previously defined network node name or enter a new name of up to 32 characters. The name is validated when you click the OK to make sure it has not been previously assigned to another PanelView in the same project.
Select the address (1 to 255) of the slave device on the
Modbus link. This address is associated with the network device selected in the Name field (above). Each node on the network should be assigned a unique address.
Select Modbus as the type. You cannot create or modify the configuration of a device with a Type defined as Other
(not Modbus).
Modbus Communications for PanelView Terminals 13
3. Under Terminal, edit the following parameters:
Specify:
Slave Response
Timeout (msec)
Baud Rate
Data Bits/Parity
To:
Enter a value between 20 and 5000 milliseconds. The default is 250. This timeout specifies the time, after a command is sent by the PanelView terminal, that an error is indicated by no response from the slave device.
Select the baud rate of the Modbus link. The available baud rates are:
300
1200
4800
9600 (Default Setting)
19200
28800
38400
Select Number of Data Bits and Parity:
8/ODD
8/EVEN
8/NONE (Default Setting)
Port Configuration/
Modem Handshaking
Note: Serial communications occur with 1 stop bit.
Select the communication port option:
RS232 (Default)
Modem
RS422
RS485
The Following Only Appear when Modem is Selected
RTS TX Delay (msec) Enter a value between 0 and 2000 milliseconds. The default is 0. This delay occurs between the asserting of
RTS and the transmission of the first character of data.
RTS Off Delay (msec) Enter a value between 0 and 2000 milliseconds. The default is 0. This delay occurs between the last data character transmitted and the deasserting of RTS.
CTS Timeout (msec) Enter a value between 0 and 2000 milliseconds. The default is 100. This timeout specifies the delay between the assertion of the RTS signal by the PanelView terminal and assertion of the CTS signal by the modem.
4. Click OK to exit and return to the Terminal Setup dialog.
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14 Modbus Communications for PanelView Terminals
Modbus Address Spaces
The PanelView reads and writes data into other Modbus devices on the same network. The Node Address specifies the device (node) and the Address Type specifies the address space. The following address types are supported:
•
Input Status (status of Modicon controller discrete input)
•
Output Coil (status of Modicon controller discrete output)
•
Input Register (contents of input register in Modicon controller)
•
Holding Register (contents of holding register in Modicon controller)
Modbus devices can contain four distinct address spaces. Two spaces are reserved for Coil data and two are reserved for Register data. The
PanelView terminal can read from any of the four address spaces.
However, the PanelView terminal can only write to the Output Coil and Holding Register address spaces.
Coil Addressing
In Write Tags
If Output Coil address type is specified in a write tag, the data is written to the Coil address using Modbus Function Code 5 (single coil) or Function Code 15 (multiple coils).
In Read Tags
If either Coil address type is specified in a read tag, data is read from the appropriate Coil address. For Input Status Coils, the status of the discrete input is read using a Modbus Function Code 2. For Output
Coils, the status of the discrete output is read using Function Code 1.
Register Addressing
In Write Tags
If Holding Register address type is specified in a write tag, data is written to the Register address using Modbus Function Code 6 (single register) or Function Code 16 (multiple registers).
In Read Tags
If an Input Register or Holding Register is selected in a read tag, data is read from the appropriate Register address using Modbus Function
Code 3 (holding register) or Function Code 4 (input register).
Publication 2711-6.9 - March 2000
Modbus Communications for PanelView Terminals 15
Data and Address Types
Not all of the data types are compatible with every address type. The following table shows the Address Type available based on the selected data type.
Data Type
Bit
4BCD
Unsigned Integer
Signed Integer
IEEE Float
Bit Array
Character Array
Compatible Address Type(s)
Input Status, Output Coil
All Address types
Input Register, Holding Register
Input Register, Holding Register
Input Register, Holding Register
Input Status, Output Coil
Input Register, Holding Register
Modicon Controller Data
Table
Address
0xxxxx
1xxxxx
3xxxxx
4xxxxx
6xxxxx
Address Type
Discrete Output or Coil (Internal)
Discrete
Input Status
Input Register
Output
Holding Register
Extended
Memory Register
Modicon controllers store read and write address spaces in the following data table locations.
Note: The PanelView does not require data addresses that conform to the address ranges provided in the following table. For each address type, the PanelView terminal supports address ranges from 0 to 65535.
For example, for a discrete input status at address 40000, the full address representation would be 140000.
Data Access
Bit Read or Write
Bit Read Only
Word Read Only
Word Read and
Write
Access through
Logic Program only
Description
Use to drive a real output through an output module or to set one or more internal coils.
A coil can be used to drive multiple contacts.
Use to drive contacts in the logic program. The Input state is controlled by an input module.
Holds numeric inputs from an external source (for example, a thumb wheel entry, an analog signal or data from a high speed counter). A 3x register can also store
16 contiguous discrete signals that are entered into the register in either binary or binary coded decimal (BCD) formats.
Use to store numerical (decimal or binary) information or to send the information to an output module.
Use to store information in an extended memory area.
Only available in PLCs with 24 bit CPUs that support extended memory such as the 984B, E984–785 and
Quantum series of PLCs.
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16 Modbus Communications for PanelView Terminals
Data Format
Modicon controllers communicate in either ASCII or RTU (Remote
Terminal Unit) transmission mode. The PanelView only supports RTU mode. In RTU mode, each 8-bit byte contains 2 four-bit hexadecimal characters. The following is supported:
•
1 start bit
•
8 data bits (least significant bit first)
•
1 bit for even/odd parity, no bit for no parity
•
1 stop bit if parity used, 2 bits if no parity selected
PanelBuilder32 Tag Editor
Use the Tag Editor or the Tag Form dialog (accessed from the object’s dialog) to enter tags. There are 2 types of tags:
• digital - for bit data types
• register - for all other data types
Tag Editor
Register Tag Form Dialog
Bit Tag Form Dialog
Publication 2711-6.9 - March 2000
Field
Tag Name
Data Type
Array Size
Description
Node Name
Tag Initial Value
Tag Address
Modbus Communications for PanelView Terminals 17
Tag Editor Fields
Description
Name of tag.
Data format of tag.
Size of array.
Description of tag.
Maximum characters = 255
Any printable character
Name of node (device) assigned to tag.
The starting value for the current tag in engineering units (used only for write tags).
Pull down list of previously defined nodes.
Maximum characters = 24
0 - 9 e, E, +, - and period
0 or 1 for bit data type
Address of the data in the slave device.
Valid Characters
Maximum characters = 32
A-Z, a-z, 0-9 hyphen (-), underscore (_), percent (%)
Select one of the following:
Bit
4BCD
Unsigned Integer
Signed Integer
IEEE Float
Bit Array
Character Array
Character arrays are 1-128 characters
Bit arrays are 1-16 bits
Notes
- Tag name must be unique.
- Can’t start with 0-9, hyphen, or percent
- Tag names are not case sensitive.
- Do not use blanks, tabs, carriage returns or non-printable characters.
Data type must be compatible with the data format selected in the object’s dialog.
0 to 65535
- Displays only if Bit Array or Character
Array are selected.
- Array size must be an integer.
- A Modbus bit array can start at any input or coil address regardless of the word boundaries.
- Do not use blanks, tabs, carriage returns or non-printable characters.
Do not use tabs, carriage returns or non-printable characters.
Each node name is associated with a node address.
- Do not use blanks, tabs, carriage returns or non-printable characters.
- Maximum precision is 6 places to the right of the decimal point for non-floating point values.
- If present, a sign (+ or -) for the number must be first (+ is default).
- If present, a sign for the exponent must immediately follow the e or E.
- No entry = default of 0.
- Do not use blanks, tabs, carriage returns or non-printable characters.
- A Modbus bit array can start at any input or coil address regardless of the word boundaries.
Publication 2711-6.9
18 Modbus Communications for PanelView Terminals
Field
Type
Scaling
Scale:
‘m’ in y = mx + b
Offset:
‘b’ in y = mx + b
Data Entry Limits
Minimum
Maximum
Description
Determines address of the data in the slave device.
Values you want to use to convert the current tag’s processor integer value (‘x’) to engineering units (‘y’).
Valid Characters
Options are:
Input Status
Output Coil
Input Register
Holding Register
Maximum characters = 12
0 - 9 e, E, +, and period
Minimum and maximum values that can be assigned to the tag.
Maximum characters = 12
0 - 9 e, E, +, and period
Notes
Address Type may support some or all of the data types. Refer to page 15.
- Do not use blanks, tabs, carriage returns or non-printable characters.
- Maximum precision for scale is 6 places to right of decimal point.
- Maximum precision for offset is 6 places to right of decimal point.
- If present, a sign (+ or -) for the number must be first (+ is default).
- If present, a sign for the exponent must immediately follow the e or E.
- Do not use blanks, tabs, carriage returns or non-printable characters.
- Maximum precision is 6 places to right of decimal point.
- If present, a sign (+ or -) for the number must be first (+ is default).
- If present, a sign for the exponent must immediately follow the e or E.
Publication 2711-6.9 - March 2000
Modbus Communications for PanelView Terminals 19
Downloading Applications over a Serial Link
To download a Modbus application from your computer to the
PanelView terminal over an RS-232 link:
• connect computer to RS-232 port of PanelView terminal
• download application from the PanelBuilder32 File menu
Downloading Application using the Internal DF1 Driver
This section shows how to download an application from a serial
COM port on your computer to the RS-232/DF1 port of the PanelView terminal using a point-to-point connection. The download uses the internal DF1 driver on your computer’s COM1- COM9 port. This driver uses fixed DF1 settings that match those of the RS-232 port of the terminal. Use the 2711-NC13 cable (9-pin connector) for the point-to-point connection. Check the cable connections before starting the download.
Open the application you want to download and select
File>Download. The application is validated during the download.
Any errors that occur during validation must be corrected before you can proceed with the download.
Starts the download
Name of application being downloaded
Select a COM port for the download
These are default settings that must match the fixed settings of the
Panelview terminal.
When the download is complete, the terminal resets, verifies and starts the application.
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20 Modbus Communications for PanelView Terminals
Modbus Application Report
The application printout for Modbus provides the following information:
• configuration data
• tag data
Error Messages and Codes
The following tables lists error messages and codes specific to
Modbus communications. For all other messages, refer to the
PanelView Operator Interface manual or the PanelBuilder32 online help.
PanelBuilder32 Tag Error Messages
Message Recommended Action
Tag Address is invalid, number must be between 0 and 65535.
Enter appropriate value (0–65535) in Tag Editor.
Character Array Size is invalid, must be between 1 and 128.
Enter appropriate value (1–128) in Tag Editor.
Maximum separation of coil tags in an alarm must be less than
1024 coils.
Maximum separation of register tags in an alarm must be less than 64 registers.
In Alarm Setup, change the alarm callout tags so that their addresses are within the specified number of coils/registers of the alarm trigger tag address.
In Alarm Setup, change the alarm callout tags so that their addresses are within the specified number of coils/registers of the alarm trigger tag address.
All tags in an alarm must reference the same network node address.
In Alarm Setup, change the alarm trigger tag and corresponding alarm callout tags to correct the error condition.
All tags in an alarm must have the same Modbus address type. In Alarm Setup, change the alarm trigger tag and corresponding alarm callout tags to correct the error condition.
All tags in an alarm must be in the same direction to/from the network node.
In Alarm Setup, change the alarm trigger tag and corresponding alarm callout tags to correct the error condition.
There cannot be more than one tag in an alarm if the data direction is to the network node.
Cannot write to an input register or input status address.
In Alarm Setup, change the alarm trigger tag and corresponding alarm callout tags to correct the error condition.
Use an output tag for an object or change the tag addresses in the Tag Editor to an output register or coil.
Not enough network address space to support a tag of this data type.
Change the tag address to reference a lower numbered discrete address or register.
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Modbus Communications for PanelView Terminals 21
The following errors are not specific to Modbus but may appear when you exit the Tag Editor.
Message
Minimum Value is invalid, must be between 0 and 9999
Minimum Value is invalid, must be between 0 and 65535
Minimum Value is invalid, must be between –32768 and 32767
Minimum Value is invalid, must be between –99999997952 and 999999995904
Maximum Value is invalid, must be between 0 and 9999
Recommended Action
Enter appropriate value in Tag Editor.
Enter appropriate value in Tag Editor.
Enter appropriate value in Tag Editor.
Enter appropriate value in Tag Editor.
Enter appropriate value in Tag Editor.
Maximum Value is invalid, must be between 0 and 65535
Maximum Value is invalid, must be between –32768 and 32767
Maximum Value is invalid, must be between 0 and 9999
Enter appropriate value in Tag Editor.
Enter appropriate value in Tag Editor.
Enter appropriate value in Tag Editor.
Scale Value is invalid, must be between –99.999997952e9 and 999,999995904e9 Enter appropriate value in Tag Editor.
Offset Value is invalid, must be between –99.999997952e9 and 999,999995904e9 Enter appropriate value in Tag Editor.
PanelBuilder32 Node Error Messages
Message
Slave Response Timeout is invalid, must be between 20 and 50000.
RTS TX Delay is invalid, must be between 0 and 2000.
RTS Off Delay is invalid, must be between 0 and 2000.
CTS Timeout is invalid, must be between 0 and 2000.
Node Address is invalid, must be between 1 and 255
Data Bits / Parity is invalid.
Port Configuration / Modem Handshaking is invalid.
Baud Rate is invalid.
Terminal node not configured.
Network node is invalid, must be Modbus type.
Recommended Action
Correct value in the Communications Setup Dialog.
Correct value in the Communications Setup Dialog.
Correct value in the Communications Setup Dialog.
Correct value in the Communications Setup Dialog.
Correct value in the Communications Setup Dialog.
Correct value in the Communications Setup Dialog.
Correct value in the Communications Setup Dialog.
Correct value in the Communications Setup Dialog.
Configure the node in the Communications Setup Dialog.
Configure the node in the Communications Setup Dialog.
PanelBuilder32 Translation Error Messages
Publication 2711-6.9
22 Modbus Communications for PanelView Terminals
Message
Not enough network node address space to support a tag of this data type.
Not enough RAM on Daughtercard to support the size of this user application file.
Translation Failure
Recommended Action
Change the tag address to reference a lower numbered discrete address or register.
Group tag addresses together as much as possible, otherwise remove screen objects.
Contact Allen-Bradley for technical support.
Publication 2711-6.9 - March 2000
Code
1
5
6
7-22
2
3
4
Modbus Communications for PanelView Terminals 23
Communication Status Error Messages
These errors appear as a banner at the top of an application screen
(error #634 in upper left corner) or as a status display on the terminal configuration screen.
Note: Since the PanelView is configured as a master device, communication status is not updated until the PanelView requests information. If communications are lost, the PanelView displays the last communication status.
Errors numbered less than 7 are considered minor fault conditions and will clear automatically when corrected. Errors numbered 7 and above require that the terminal be reset to clear the error.
Indicates
No connections established. Occurs on power–up until a device connection is established on the network.
Invalid Messages (Parity Error). The Parity received by the
PanelView is invalid.
Error Reply Messages (Application Error). Error indicates that the Modbus device does not support a coil or register address requested by the PanelView terminal.
Error Detect Failures (CRC Error). Indicates that the messages from a Modbus device contain an invalid Cyclic
Redundancy Check.
Loss of Communications (Rx Timeout). Indicates Modbus device is not responding.
Recommended Action
Establish a connection over Modbus to the
PanelView.
Check that the parity of both the PanelView terminal and Modbus device are set the same.
Verify the coil and register addresses used in the application.
Verify the address of each Modbus device and cabling to each device.
Modem Failure (CTS Timeout Failure). Indicates that the modem failed to assert the CTS line within the time specified on the configuration screen.
Internal Errors
Verify that the Modbus device supports RTU communications.
Check the cabling and, if necessary, increase the CTS timeout on the communications configuration screen.
Reset Terminal, Contact Allen–Bradley technical support if problem reoccurs.
Publication 2711-6.9
Glossary
Coil
Bit location in a a Modbus device.
Digital Tag
A bit address.
Inputs
Data which is received by the logic controller from other devices.
Master
Device which sends messages (queries) to one or more slave devices.
Modicon Controller
Refers to the 184/384, 484, 584, 884, M84 (micro), or 984 family of
Modicon logic controllers.
Outputs
Data which is sent by a logic controller to other devices.
Register
16 bit unsigned value residing in a Modbus device.
RTU
Acronym for Remote Terminal Unit, one of 2 possible transmission formats supported by Modbus. PanelView terminals only support
RTU.
Slave
Device which receives queries from the master and provides a response.
Publication 2711-6.9 - March 2000
24
Supersedes Publication 2711-6.9 - October 1997
40061-386-01(B)
© Copyright 2000 Rockwell International Corporation. Printed in the U.S.A.
