OMRON HOST LINK TO RS-485 TO OPC

[josedavidch]

Hi

I have a challenge connecting 3 PLC OMRON CQM1H-CPU21 whose only networking option (as far as I know) is to use the available RS-232 port, conver it to RS-485 and then hook up the 3 PLCS to a computer where I have a OPC driver for Omron Host Link. Now, I am not sure if after convert to RS-485 I will still have the HOST LINK so the OPC can talk the PLCs assigning an unique ID to each over the 485 network.

Does some one has experience on this matter?

Please advice.

David

[BeCeGa]

Hi David why are you changing the communication from RS232 to RS485?,  Maybe you could use some extra serial RS232 ports in your computer ? Here the main subject would be if your OPC server has support for the RS485. Also there are several providers of Omron Host link OPC server. In most of them you would be able to control one PLC with a serial port, or several depending on the communication method. For example with the Klinkmann version:

"The following steps are taken to define the topics (controllers) connected to OMRHLINK

Server. The connection can be direct (default) if communicating with controller via serial

or multi-dropped serial configuration or networked if communicating with controller that is

on some of OMRON FA (Factory Automation) networks (e.g. Ethernet or Controller Link)"

http://www.klinkmann.com/CD/doc/480XXM10.PDF

Still it might be easier to configure if you use a RS232 Port for the each PLC, if you dont have enough ports, we have PCI, or USB Serial ports:

http://www.ni.com/serial/

Hope this helps