The feedback storage parameter is selectable in the source selection parameters 40.8
Set 1 feedback 1 source and 40.9 Set 1 feedback 2 source.
The corresponding parameters in process PID control set 2 (group 41 Process PID set
2) have the same selections.
￭ 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.
Modern Modbus master devices typically provide a means to access the full range of
65536 Modbus holding registers. One of these methods is to use 6-digit decimal
addresses from 400001 to 465536. This manual uses 6-digit decimal addressing to
represent Modbus holding register addresses.
Modbus master devices that are limited to the 5-digit decimal addressing may still access
registers 400001 to 409999 by using 5-digit decimal addresses 40001 to 49999. Registers
410000 to 465536 are inaccessible to these masters.
Note: Register addresses of 32-bit parameters cannot be accessed by using 5-digit
register numbers.
About the control profiles
A control profile defines the rules for data transfer between the drive and the fieldbus
master, for example:
• if packed boolean words are converted and how
• how drive register addresses are mapped for the fieldbus master.
You can configure the drive to receive and send messages according to the ABB Drives
profile or the Transparent profile. With the ABB Drives profile, the embedded fieldbus
interface of the drive converts the control word and status word to and from the native
data used in the drive. The Transparent profile involves no data conversion. The figure
below illustrates the effect of the profile selection.
Fieldbus control through the embedded fieldbus interface (EFB) 595
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