376 Fieldbus control through the embedded fieldbus interface (EFB)
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 410000-465536 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
• if signal values are scaled and how
• how drive register addresses are mapped for the fieldbus master.
You can configure the drive to receive and send messages according to one of the
two profiles:
• ABB Drives
• DCU Profile.
For the ABB Drives profile, the embedded fieldbus interface of the drive converts the
fieldbus data to and from the native data used in the drive. The DCU Profile involves
no data conversion or scaling. The figure below illustrates the effect of the profile
selection.
Profile selection
Control profile selection with parameter 58.25 Control profile is:
•(0) ABB Drives
•(5) DCU Profile.
58.25
SEL
Data
conversion &
scaling
0
5
Fieldbus
Drive
58.26…58.29
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