This document describes the MODBUS communication driver for Canvas. This driver supports the RTU (serial) version of the MODBUS protocol.
Communication Setup: Canvas
I/O Device Configuration
| To create a new device, select [Tools] → [I/O Device Editor]. Click the Device Name: Give a device name. This name will be used in the tag database, accompanid by the ‘Station Name’. |
I/O Device Settings
| Once the connection type, device name, and device type have been assigned, the [I/O Device Editor] window populates with the default settings for the selected communication protocol. After selecting the correct [Connection Type] and [Device Type], match the remaining settings to the target I/O device’s communication settings. |
Station | In this window, users can assign a Station Name and ID for the target I/O Device. |
Communication Settings: PLC
Comm. Module | If using one of the following PLC modules to communicate with Xpanel, the card settings must be configured in CICON as shown below:
Note that the [CH 1] tab is for usage with RS232 connections, while the [CH 2] tab is for usage with RS485 connections. All communication parameters must match the settings chosen during the I/O device configuration in Canvas. Once the correct parameters have been entered, press the [Write] button while online with the PLC to update the communication parameters. |
CPU built-in Comm. port | If using a built-in CPU (PLC) serial port to communicate with Xpanel, the channel settings must be configured in CICON as shown below: This connection option is available with the following models:
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Address Notation
The following table shows the list of valid address ranges and MODBUS function codes for each address area.
Area | Symbol | Analog Tag | Digital Tag | Read | Write |
Coil | 0 |
| 000001 - 0299991 | 1 | 5 |
Input | 1 |
| 100001 - 129999 | 2 |
|
Holding Register | 4 | 400001 - 429999 |
| 3 | 6, 162 |
Input Register | 3 | 300001 - 329999 |
| 4 |
|
Notes:
The symbol character (0, 1, 3, or 4) must be placed in the first position of the address string. The address number follows the symbol character.
The symbol character does not behave as a number. For example, 400100 and 40100 designate the same memory area (holding register 100).
The memory areas listed above are provided for general purposes. The actual available memory area and range of each area should be checked using the manual for the connected device. The ‘Read’/’Write’ columns show the MODBUS function codes used in this communication driver.
Code 16 is issued for writing double words or when the recipe write function is activated. When writing single words, code 6 is used.
Communication Cable Wiring
XPANEL COM/CPM2 RS-232C | |
XPANEL COM1 RS-422/485 |
The above picture shows the RS-232C and RS-422/485 ports of the Xpanel. Refer to the manual of your device for signal descriptions.
For the RS-232C ports, Xpanel provides the standard DB9 RS-232C pin assignment. Typically RD, TD, and SG pins are enough to communicate with a general MODBUS device.