Thread Starter

Kashir Saeed

Dear Experts,

I have an app1lication in which i have to share data between 2 PLCs 1 of them is using MODBUS PLUS and MODBUS while other can send/receive data in the form MODBUS TCP, RTU, ASCII. But my problem is from the modicon plc only available slot is MODBUS PLUS other port is in use and i have to fetch data through this port. while my other PLCs don't have the MODBUS plus option.

So how can i get the data in which my 2nd PLC easily understand the protocol.

your earlier response will be highly appreciable.

Thanks in advance.
Kashir Saeed
Automation Engineer
[email protected]
I would add that Modbus/PLUS is a high-speed bus (relative to serial) which includes concepts of shared-data 'multicast' to groups, sub-second updates and so on, so it is NOT a simple RS-485 link, as some people believe.

In the end, you WILL need to buy a fairly beefy 'node' to act as a certified 'peer' on the bus. I'd take a close look at your needs - if all you need is to move a few registers every few seconds & are NOT using the MB+ special features, sticking to old Modbus/RTu serial will be fine and save you a lot of money.