ABB ACS280, Firmware Manual, Page: 357 / 430

Fieldbus control through the embedded fieldbus interface (EFB)
357
the EFB CW as the source of drive control commands (such as start/stop,
emergency stop, selection between external control locations 1/2, or fault
reset). The drive switches between its states according to the bit-coded
instructions of the CW.
The fieldbus CW is either written to the drive as it is or the data is converted.
See section
About the control profiles
on page
358
.
The fieldbus Status Word (SW) is a 16-bit or 32-bit packed boolean word. It
contains status information from the drive to the fieldbus controller. The drive
SW is either written to the fieldbus SW as it is or the data is converted. See
section
About the control profiles
on page
358
.

References
EFB references 1 and 2 are 16-bit or 32-bit signed integers. The contents of each
reference word can be used as the source of virtually any signal, such as the
speed, frequency, torque or process reference. In embedded fieldbus
communication, references 1 and 2 are displayed by
03.09 EFB reference 1
and
03.10 EFB reference 2
respectively. Whether the references are scaled or not
depends on the settings of
58.26 EFB ref1 type
and
58.27 EFB ref2 type
. See section
About the control profiles
on page
358
.
 Actual values
Fieldbus actual signals (ACT1 and ACT2) are 16-bit or 32-bit signed integers.
They convey selected drive parameter values from the drive to the master.
Whether the actual values are scaled or not depends on the settings of
58.28 EFB
act1 type
and
58.29 EFB act2 type
. See section
About the control profiles
on page
358
.
 Data input/outputs
Data input/outputs are 16-bit or 32-bit words containing selected drive
parameter values. Parameters
58.101 Data I/O 1
…
58.114 Data I/O 14
define the
addresses from which the master either reads data (input) or to which it writes
data (output).
 Register addressing
The address field of Modbus requests for accessing holding registers is 16 bits.
This allows the Modbus protocol to support addressing of 65536 holding
registers.
Historically, Modbus master devices used 5-digit decimal addresses from 40001
to 49999 to represent holding register addresses. The 5-digit decimal
addressing limited to 9999 the number of holding registers that could be
addressed.