ABB ACQ810 - References for the DCU 32-Bit Profile

Control through the embedded fieldbus interface 351
 References for the DCU 32-bit profile
The DCU 32-bit profile supports the use of two fieldbus references, REF1 and REF2.
The references 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 value. A negative reference is formed by calculating the two’s complement
from the corresponding positive value of the integer part (MSW).
The fieldbus references are written as is into the drive reference values (02.38 EFB
main ref1 or 02.39 EFB main ref2). Parameters 50.04 FBA ref1 modesel and 50.05
FBA ref2 modesel define the reference types (speed or torque) as follows:
• If you select value Raw data, the fieldbus reference type or possible use is not
selected. The value is freely usable as a speed or torque reference in the drive.
The table below clarifies the relation between the fieldbus reference and drive
reference (no scaling).
1)
If the reference value is used as the speed reference, it will be the motor speed in rpm. If the reference
value is used as the torque reference, it will be the motor torque in percent of the motor nominal torque.
• If you select value Speed, the fieldbus reference can be used as a speed
reference in the drive. The table below clarifies the relation between the fieldbus
reference and drive reference (no scaling).
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 fieldbus 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 FBA ref1 modesel and 50.05 FBA ref2 modesel select the drive
actual signals for the fieldbus actual values ACT1 and ACT2 respectively as follows:
• If you select value Raw data, the drive parameters 50.06 FBA act1 tr src
and
50.07 FBA act2 tr src select the drive parameters for the fieldbus actual value
Fieldbus reference REF1 or REF2
[integer and fractional part]
Corresponding reference
in the drive [rpm or %]
1)
32767.65535 32767.65535
00
-32768.65535 -32768.65535
Fieldbus reference REF1 or REF2
[integer and fractional part]
Corresponding speed reference
in the drive [rpm]
32767.65535 32767.65535
00
-32768.65535 -32768.65535