Modbus Write to ABB ACS550

[Suncoast Controls]

Hi Guys,

Just doing a addition on a project 

I have 12  x VSD danfoss drives working great over the last 12 months on  Modbus TCP,/IP. Using control word and speed reference for control, the client has just installed a ABB drive a ACS550,  taking the modbus drive count to 13, I can easily poll the drive and read the drive feed back like 102 (40102) etc,  However I am having difficulty writing the control word as a Hex code of 04FF  to (1) or 40001 to start the drive  or the speed reference between 0-20,000 to  (2) 40002 Does anyone have any  ideas I have tried both 0 &1 as zero offsets but still can't seem to get the drive to receive the control or speed.

All drive paramteters for ABB profile is set to Comm as per the documentation for fieldbus control setup over modbus

Has anyone come across this issue with unistream writing to these drives and are there any tips or tricks I might have missed  ? 

Thanks in advance 

Douglas

[Ofir]

Hi,

What is the register size of the control word? (16 or 32bit)

If it is 32bit , please make sure that the register defined is also 32bit.

If I'm not wrong 40001 should be address 0

You can also try to write the data using MODSCAN32 (PC application) in order to find out where is the issue.