Modbus and cFP-DI-304 data packet

[irizge]

I’m using a host computer to communicate with the cFP-DI-304 using Modbus over Ethernet.

When the cFP-DI-304 (revision D) is polled, it is returning incorrect data (looks like a timing issue). What is the sequence and data package when the cFP-DI-304 gets polled?  Does the data sequence starts from pin 1 to pin 32, pin 32 to pin 1, or some other combination? Also is the package 8 or 16 bits?

[RavensFan]

Please post any VI's you have for doing this communication.  Is the cFP-DI module on a backplane with a cFP controller or a communications module?

I'm not familiar with using ModBUS to communicate with individual cFP modules.  The usual method is to use datasockets or shared variables.

[irizge]

The cFP-DI-304 is connected to the cFP-1804. I’m using a host computer to communicate with the cFP-DI-304 using Modbus over Ethernet.