UniCAN and Modbus COMMUNICATION Together

[Arun Luthra]

Dear all,

I am using two v570(PLC A and PLC between two PLCs we are using UniCAN protocol and PLC A is also communication with PC using Modbus protocol I need to know how I will communicate with PLC B via PLC A through PC.

[Simon]

Hello,

With those protocols, you are restricted to a 2-step process:

Using UniCAN, synchronsie the live data from PLC B to a local copy in PLC A

Using Modbus, read/write from the local copy in PLC A to the PC.

Other options:

* Use DDE or OPC server in PC to talk to PLC A, then use the CAN pass-trhough function to read/write data in PLC B directly from the PC software.

* If you are on ModbusRTU, extend the RS485 link to PLC B, replacing the CAN bus. Then you can read/write both PLCs directly with ModbusRTU.

[Emil]

You just need to give different ID numbers of A & B OPLC - let's say ID1 and ID2. Then, from PC via VisiLogic (good for test), Remote access, Remote operator or your SCADA you can access both units via their ID addresses, when one unit is connected to PC (RS232/485 or Ethernet) and both units are connected via CANbus. PCOM over CAN is running in parallel with UniCAN.

In your SCADA tiy will need to use OPC Server.

[Arun Luthra]

You just need to give different ID numbers of A & B OPLC - let's say ID1 and ID2. Then, from PC via VisiLogic (good for test), Remote access, Remote operator or your SCADA you can access both units via their ID addresses, when one unit is connected to PC (RS232/485 or Ethernet) and both units are connected via CANbus. PCOM over CAN is running in parallel with UniCAN.

In your SCADA tiy will need to use OPC Server.

That i know that using the visi logic it is working but if i need to communication using SCADA what to do with that ..

How that unitronics software visilogic communication on UniCAN with the serial cable connected on one PLC over the network and other can access only by selecting the ID that i need do using SCADA.