Communication between Virtual PLC and LabVIEW via Modbus TCP/IP

[Fred19ni]

Hi,

I did some programs on LabVIEW which can communicate via MODBUS TCP/IP between 2 PCs. But now I would like to use a Virtual PLC which deploy a virtual IP adress. Therefore I could use my LabVIEW program to communite with this virtual PLC.

could you please advise me which Virtual PLC that I can use ?

someone here have already try it please ?

[KingPGeorge]

Hi Fred,

There isn't really anything I can point you towards as far as compatibility with Virtual PLCs goes. Since you've worked with the API, you've probably observed that with TCP/IP you just need an IP address. My only suggestion is to give it a try. If you can reach the IP address of your device, you should be able to establish communication.

Thanks,

Peter George

Applications Engineer

National Instruments

[Fred19ni]

Hi george,

Thanks for you repply.

I have already try to communicate with two PCs, and it's ok.

I have another question :

If I would like to communicate with a PLC already installed. How can I have access to I/O (of PLC) from register?

Thnaks in advance.

[pincpanter · Accepted solution]

The PLC software will imply a mapping of the physical/logical I/O onto the MODBUS address space.

This map will depend on the application and should be documented by the PLC progammer.