Hardware manual

Fieldbus control description

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 20

presents the most important states (including the FBA profile state names). The FBA

Control Word (parameter 2.24) commands the transitions between these states and

the FBA Status Word (parameter 2.26) 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

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.

Fieldbus references and scaling

References (FBA REF) are 16/32-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 torque reference. The 32-bit reference

value consists of a 16-bit integer value and a 16-bit fractional value.

When speed or torque reference scaling is selected (by parameter 50.04 FBA REF1

MODESEL / 50.05 FBA REF2 MODESEL), the fieldbus references are 16- or 32-bit

integers. In the table below, FBA REF denotes either the drive parameter 2.26 FBA

MAIN REF1 or the parameter 2.27 FBA MAIN REF2. The speed/torque reference

scaling is as follows:

Reference Scaling Notes

Speed reference FBA REF / 65536

(value in rpm)

Final reference is limited by parameters 20.01 MAXIMUM

SPEED, 20.02 MINIMUM SPEED and 21.09 SPEED

REFMIN ABS.

Torque reference FBA REF/ 65536

(value in%)

Final reference is limited by torque limit parameters

20.06 ... 20.10