Example of Application of MODICON (MODBUS) protocol
- CIMON (Unlicensed)
It is available to configure a communication system and frames between a CIMON-PLC and other manufacturer’s PLC using Modbus Protocol.
The following is an example for request to read 16-bit data from other manufacturer’s PLC using Modbus Protocol to a CIMON-PLC. If a requesting frame is received from other manufacturer’s PLC, the received frame will be evaluated. If correct, it will be sent automatically.
Structure of Modbus Protocol Request (Other manufacturer’s PLC)
Slave Address | Function | Starting Address(H) | Start Address(L) | No. Point(H) | No. Point(H) | BCC(H) | BCC(L) |
01 | 01 | 00 | 01 | 0 | 16 | ? | ? |
Structure of Modbus Protocol Response (CIMON-PLC)
Slave Address | Function | Byte Count | Data | Data | BCC(H) | BCC(L) |
01 | 01 | 02 | CD | 6B | ? | ? |
Setting up the requesting frame received from other manufacturer’s PLC
Select the auto-send after receiving. But, the frame sent automatically is to be registered.
Setting up a responding frame
PLC Program:
If Data Value L0000 is ‘1’, the received data is evaluated. The frame registered to the auto-send after receiving is sent without SEND command. Also, M0000 is or-operated and the above will be continuously processed if a frame is received.