Micro800 and modbus RTU CRC

Hi All,

I'm currently working on a project with some fuji drives (frenic mini) and a micro850. Communication is through Modbus RTU. I don't have much experience with modbus rtu, but I have a general understanding of it. I'm curious if anyone here knows if the MODBUS_MSG in CCW handles the CRC automatically. I ask this, because in all the available datatype fields related to the modbus_msg I don't see any that seem relevant to CRC. If you choose the CIP serial option in the controller settings, there is an option below that for CRC (or BCC), but there is no option like that when modbus rtu is selected. Can anyone please chime in here? Regardles, I would love to talk to anyone who has successfully worked with the micro800 series and drives communicating via Modbus RTU to bounce a few questions around. Thanks in advance!

Dan

Don't know the specifics for the Micro800, but usually when the device is advertised as having Modbus functionality, the vendor has programmed the CRC calculation as part of the Modbus package. In fact, I am unaware of any commercial Modbus implementation that leaves the CRC calculation up to the user.

I would take the lack of a CRC data entry field as a good sign - the vendor is handling that task.

danw said:

Don't know the specifics for the Micro800, but usually when the device is advertised as having Modbus functionality, the vendor has programmed the CRC calculation as part of the Modbus package. In fact, I am unaware of any commercial Modbus implementation that leaves the CRC calculation up to the user.

I would take the lack of a CRC data entry field as a good sign - the vendor is handling that task.

Click to expand...

Haha. Thanks Danw. That's what I though, and also what I was hoping the answer would be.