andrewp

MNET to OMNI

5 posts in this topic

Good morning all, does anyone have any experience communicating to an OMNI Flow Computer through a MNET card, Im getting data back but it is not what i expected.  Should I be using Enron/Daniels? Byte Swapping? Thanks

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I’m traveling at the moment so I can’t look at what I’ve done in the past, but as I remember it, Omni uses standard Modbus protocol. I haven’t used an MNET card in a long time. Red Lion DSPGT’s work as well and cost less. 

OMNI has a nice little free modbus polling program. You could poll a register, view it in bytes or bits, compare it to what you are seeing

 

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Omni has some registers that are regular MODBUS and other registers that are Enron MODBUS. Omni produces the "MODBUS database addresses and index numbers" user manual for the flow computer/firmware revisions.

For example:

example.png

Depending on the register index, requesting 1 register could get you 1, 2, 4 or 8 words (1 word = 16 bits).

Edited by Mark-

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Ok, so, it looks like the floats have to be "word swap" when you set up the commands in the MNET. Problem solved. Thank you fellas

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Has anyone written a string to an OMNI via MCM-MVI56?

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