ABB ACS350 Series, User Manual

Page: 271 / 314

Fieldbus control with fieldbus adapter
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The Control Word and the Status Word
The Control Word (CW) is the principal means of controlling the drive from a fieldbus
system. The Control Word is sent by the fieldbus controller to the drive. The drive
switches between its states according to the bit-coded instructions of the Control
Word.
The Status Word (SW) is a word containing status information, sent by the drive to
the fieldbus controller.
References
References (REF) are 16-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 speed or frequency reference.
Actual Values
Actual Values (ACT) are 16-bit words containing information on selected operations
of the drive.
Communication profile
The communication between the drive and the fieldbus adapter supports the DCU
communication profile. The DCU profile extends the control and status interface to
32 bits.
Data
conversion
Fieldbus adapter
ABB Drives
Transparent 16
Transparent 32
Drive
Optional
reference, actual
value scaling
1)
1)
Data
conversion
Select
2)
1)
DCU profile
2)
Selection via fieldbus adapter configuration parameters (parameter group 51 EXT
COMM MODULE )
Fieldbus network
Industry standard drive
profile
(e.g. PROFIdrive)