ABB ACS850 series, Manual

Page: 335 / 370

Control through the embedded fieldbus interface 335
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Actual signals for the DCU 32-bit profile
The DCU 32-bit profile supports the use of two fieldbus actual values, ACT1 and
ACT2. The actual values are 32-bit values consisting of two 16-bit words. The MSW
(Most significant word) is the integer part and the LSW (Least significant word) the
fractional part of the 32-bit value. A negative reference is formed by calculating the
two’s complement from the corresponding positive value of the integer part (MSW).
Parameters 50.04 Fb ref1 modesel and 50.05 Fb ref2 modesel select the drive actual
signals for the fieldbus actual values ACT1 and ACT2 respectively as follows:
• If you select value Raw data , drive parameters 50.06 Fb act1 tr src and 50.07 Fb
act2 tr src select the drive parameters for the fieldbus actual value ACT1 and
ACT2 respectively.
• If you select value Speed , drive parameter 01.01 Motor speed rpm will be written
to fieldbus actual value.
• If you select value Torque , drive parameter 01.06 Motor torque will be written to
the fieldbus actual value.
The table below clarifies the relation between the value of drive parameter and
fieldbus actual value (no scaling).
Value of the selected drive signal Corresponding fieldbus actual value
ACT1 or ACT2 [integer and fractional
part]
32767.65535 32767.65535
0 0
-32768.65535 -32768.65535