ABB ACS560, Firmware Manual

Page: 437 / 514

Fieldbus control through the embedded fieldbus interface (EFB) 437
9
Fieldbus control through the
embedded fieldbus interface
(EFB)
What this chapter contains
The chapter describes how the drive can be controlled by external devices over a
communication network (fieldbus) using the embedded fieldbus interface.
System overview
The drive can be connected to an external control system through a communication
link using either a fieldbus adapter or the embedded fieldbus interface.
The embedded fieldbus interface supports the Modbus RTU protocol. The drive
control program can handle 10 Modbus registers in a 10-millisecond time level. For
example, if the drive receives a request to read 20 registers, it will start its response
within 22 ms of receiving the request – 20 ms for processing the request and 2 ms
overhead for handling the bus. The actual response time depends on other factors as
well, such as the baud rate (a parameter setting in the drive).
The drive can be set to receive all of its control information through the fieldbus
interface, or the control can be distributed between the embedded fieldbus interface
and other available sources, for example, digital and analog inputs.
Connecting the fieldbus to the drive
Connect the fieldbus to terminal slot, which is attached on the control unit of the drive.
The connection diagram is shown below.