I have a variable frequency drive attached to an Arduino via an RS485 module. I've got communication working between the two, but I'm clearly sending the wrong command address or words as I'm getting a reply I don't understand, and not seeing the actions I'd expect.
At the moment I'm just trying to verify that I understand what's going on, and that I can activate the VFD, so I'm sending:
0x01 0x06 0x00 0x20 0x01 0x00 0x89 0x90
Which is addressing device 0x01 with command 0x06 (write), address 0x2000, command 0x0001 and then a two byte CRC. Note that low bites are sent before high bytes as per the manual of this device.
The response I'm getting is:
0x01 0x06 0x80 0x01 0x00 0x04 0xF0 0x09 0x00
I'm 0x01 and 0x06 are the repeat of the address and command I sent, which makes sense, and the final two bytes are a correct CRC for this message. But the 0x80 and other bytes don't seem to be an error I can find in the manual, or anything that makes sense to me...
The manual is here: Dropbox - KOC100 Series User Manual--20150119(V1.1).pdf - Simplify your life
The description of the modbus interface begins on page 162, and the command I'm trying to use is at the top of page 167.
Hopefully somebody out there knows what's going on here!
Thanks in advance.