ABB FSO-21, User Manual

Page: 197 / 540

PROFIsafe 197
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System overview
This figure shows an overview of a safety PLC that is connected to the ACS880 drive
via the PROFIsafe communication bus.
The FSO-21 safety functions module and the FB module are installed on the ACS880
drive. The safety PLC is connected to the FB module, which communicates with the
FSO module. The safety PLC activates safety functions via the PROFIsafe
communication bus. The user can also activate safety functions from an I/O device
(for example, an emergency stop button) which is connected to the FSO module.
The PROFIsafe protocol secures the whole path from the location where a safety
signal originates to the location where it is processed and vice versa.
The safety PLC sends PROFIsafe messages (frames) to the FSO module through
the FB module which extracts the frame from the PROFINET communication. The
FSO module reads and interprets the PROFIsafe messages and performs the
required actions. The FSO module sends PROFIsafe messages back to the FB
module which transmits them to the safety PLC.
The term PROFIsafe F-Output data refers to the application-specific user data in the
frames that are transmitted to the FSO module (F-Device) from the safety PLC (F-
Host). The term PROFIsafe F-Input data refers to the application-specific user data in
the frames that are transmitted from the FSO module to the safety PLC. For a
F-Output data
Safety PLC
system controller
(F-Host)
ACS880 drive
FSO-21
(F-Device)
FB module
PROFIsafe over PROFINET
Control Byte
CRC
F-Input data
Status Byte CRC