ACS550 data format

[shivels]

Hi all,

I have a question about the way data is formated for a Modbus system.  I am using an ACS550 to operate a motor.  According to the Fieldbus interface manual, 1151 is the control word required to turn the motor on and 1143 is the control word to inhibit operation.  But when I look at the ACS550 user manual, all it shows is a table with values like "Bit: 1, Name: Off1 Control, Value:1, Commanded State: Ready to Operate'  How does 1151 breakdown to mean "turn motor on?" How is the control word structured, I can't seem to find any information about this in the user manual.  

Cheers,

Shivels

[Verne_D]

Could you post a PDF copy of the manual to this forum? (make sure that it's legal to do so first )

[Brian_Beal]

1143 and 1151 are the decimal equivalents of setting the correct bits in the control word.  It is kind of cheating to do it that way, but it works.  There is an ABB fieldbus document that explains which bits in the control word to turn on, and in the proper order.  You watch bits in the status word before proceeding to the next step.  1143/1151 works for most applications, though.