Data transfer between Labview and PLC

[SIM GUY]

Hello,

I am currently upgrading a Labview VI which acts as a plant Simulator (Gas Turbine) to test an Allen Bradley RS Logix 5000 program.

I can't figure out how the Simulator imports/exports the PLC's i/o's.

The PLC packs the SIm data into an array to send to the Simulator, and the Simulator then seems to initialise the data using an "Index" value.

I cannot however, find any consistency between these index values and the i/o tags in the PLC or the bits in the SIM array.

Does anyone have any info on how data is imported/exported to Labview from a PLC?

Any help is greatly appreciated.

I have attached a screen shot of the block diagram to maybe show things more clearly.

Thanks

Message Edited by SIM GUY on 02-03-2009 04:31 AM

[Wayne.C]

SIM GUY,

Would need to see more of the vi, but it may be using OPC Server.  Could also be communicating directly with the PLC via a serial or ethernet port.