ABB FSCA-01, User Manual

Page: 66 / 90

66 Communication profiles
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References
References are 16-bit words 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.
ABB drives can receive control information from multiple sources
including analog and digital inputs, the drive control panel and a
communication module (for example, FSCA-01). To have the drive
controlled through the fieldbus, the module must be defined as the
source for control information, for example, reference.
Scaling
References are scaled as shown below.
Note: The values of REF1 MAX and REF2 MAX are set with drive
parameters. See the drive manuals for further information.
In ACSM1, ACS850, ACQ810, ACS880, ACS860 and ACS530 the
speed reference (REFx) in decimal (0…20000) corresponds to
0…100% of the speed scaling value (as defined with a drive
parameter, eg, ACS880 parameter 46.01 Speed scaling).
In ACS355, drive parameter REFx MIN may limit the actual
minimum reference.
Drive Fieldbus
0
REFx MAX / Speed scale
-(REFx MAX) / Speed scale
0
REF2: -10000
REF1: -20000
REF2: 10000
REF1: 20000