We have quite a few Flex I/O devices on our DeviceNet segments. We have always used discrete cards until recently. We tried to add a T-couple/mV card (1794-IT8) recently without success. The default for this card is 11 input words and 4 output words (22 and 8 bytes). When I change the device properties to include this card, the device quits communicating. This is typical if you don't have the right byte sizes. I have played around with the byte numbers w/o success.
Try A/B's RSNETWORX software using RSLYNX and their devicenet modem. It will give the byte count. Alternately, connect the device to DV BUT with a different devicenet ID. Then it will show up in diagnostics with the in/out byte count. RSNETWORX is still preferred as with it you can print the memory map. I have done scaling with AI/AO cards. Use the largest word size available to conserve DST's (you can decompose AI/AO/DI/DO from it and thus save DST's -- 2 for one for analog, 8 or 16 for 1 for discrete).
In reply to Frank Seipel:
We are in the process of adding the 1794-IE8 Analog input card. I will report back what we did.