ABB ACQ810, Firmware Manual

Page: 363 / 376

Control through a fieldbus adapter 363
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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.
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Actual values
Actual values (ACT) are 16/32-bit words containing information on selected
operations of the drive.
FBA communication profile
The FBA communication profile is a state machine model which describes the
general states and state transitions of the drive. The
State diagram on page 365
presents the most important states (including the FBA profile state names). The FBA
Control Word (parameter
02.24 – see page 117 ) commands the transitions between
these states and the FBA Status Word (parameter 02.26 – see page 118 ) indicates
the status of the drive.
Fieldbus adapter module profile (selected by adapter module parameter) defines how
the control word and status word are transmitted in a system which consists of
fieldbus controller, fieldbus adapter module and drive. With transparent modes,
control word and status word are transmitted without any conversion between the
fieldbus controller and the drive. With other profiles (e.g. PROFIdrive for FPBA-01,
AC/DC drive for FDNA-01, and ABB Drives profile for all fieldbus adapter modules)
fieldbus adapter module converts the fieldbus-specific control word to the FBA
communication profile and status word from FBA communication profile to the
fieldbus-specific status word.
For descriptions of other profiles, see the User’s Manual of the appropriate fieldbus
adapter module.