ACS550 and M580 PLC INVERT SPEED REF. ERROR

[cedric.turmel]

Hi,
Has anyone had this problem:
- I send a speed reference to my ABB ACS550 Drive via Modbus TCP to it's register via an INT. However when I have to transfer a modified project to the PLC sometimes I have to invert the BYTES of the INT for the speed reference I send to the drive or else it receives the wrong reference and the drive gives DIR LOCK error 2004.

If I redo a project transfer to the PLC everything comes back to normal.
My quick fix was to add a bool to activate if needed to reverse the INT.

I would like top permenately fix this proble. Spoke with ABB and they never heard of this issue.

Any help?

 

[ojz0r]

Just to determine whats wrong, try to capture the communication using wireshark - when its woking and not to rule out the control system.