ABB ACS850 series, Firmware Manual

Page: 250 / 260

250 Fieldbus control
„
Fieldbus references
References (FBA REF) are 16/32-bit signed integers. A negative reference
(indicating reversed direction of rotation) is formed by calculating the two’s
complement from the corresponding positive reference value. The contents of each
reference word can be used as torque or speed reference.
When torque or speed reference scaling is selected (by parameter 50.04 Fba ref1
modesel / 50.05 Fba ref2 modesel ), the fieldbus references are 32-bit integers. The
value consists of a 16-bit integer value and a 16-bit fractional value. The
speed/torque reference scaling is as follows:
Reference Scaling Notes
Speed reference FBA REF / 65536
(value in rpm) Final reference is limited by parameters
20.01 Maximum speed , 20.02 Minimum
speed and 21.09 SpeedRef min abs .
Torque reference FBA REF / 65536
(value in %) Final reference is limited by torque limit
parameters
20.06 … 20.10 .