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Reference of the DSP 402 profile
In the velocity operation mode, the reference is called Target
velocity (CoE object 0x6042 hex). It is a 16-bit word containing a
sign bit and a 15.bit integer. A negative reference (indicating
reversed direction of rotation) is formed by calculating the two's
complement from the corresponding positive reference. The
reference is used to control the speed of the drive.
The unit of the target velocity is rpm. This value can be scaled with
the Vl dimension factor object (CoE object 0x604C hex):
Reference to drive = Target velocity * Vl dimension factor
The scaling is 1 by default.
Actual value of the DSP 402 profile
In the velocity operation mode, the actual value is called Control
effort (CoE object 0x6044 hex). It is a 16-bit word containing a
sign bit and a 15.bit integer. A negative reference (indicating
reversed direction of rotation) is formed by calculating the two's
complement from the corresponding positive reference. The
actual value is used by the master to monitor the actual speed of
the drive.
The unit of the control effort is rpm. This value can be scaled with
the Vl dimension factor object (CoE object 0x604C hex):
Drive actual speed = Control effort * Vl dimension factor
The scaling is 1 by default.
ABB Drives communication profile
The control word and the status word
The Control Word is the principal means for controlling the drive
from a fieldbus system. It is sent by the fieldbus master station to
the drive through the adapter module. The drive switches between
its states according to the bit-coded instructions on the Control
Word, and returns status information to the master in the Status
Word.
Communication profiles
39
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