ABB FSO-12, User Manual

Page: 46 / 388

46 Safety functions
General

Safety function request
A safety function can be activated locally from FSO digital inputs, from a safety PLC,
in FSO internal fault situations or by another safety function (see section
Dependencies between safety functions on page 134 ).
If you want to control a safety function with a push button, connect an activation
button to an FSO digital input. 24 V in the input is the non-request for a safety
function and 0 V is the request.
Note: The FSO module executes the requested safety function even if the request is
removed before the function has reached the acknowledgement criteria.
Note: With one input it is possible to activate up to two separate safety functions.
A request activates both functions simultaneously. For the execution order, see
section
Priorities between safety functions (page 134 ).
Note: The FSO module does not react to activation requests of the safety functions
during the boot.

Acknowledgement methods
You can configure the acknowledgement method separately for the start-up, STO
(SSE and SS1 always end in drive STO), SLS and POUS safety functions.
ID Description
A Normal request: The request is recognized when the button is pressed. The pressing
time of the button must be at least 20 ms.
Note : The safety function request must be removed before the acknowledgement is
accepted.
B Short low signals (less than 20 ms) are ignored.
C Safety function is activated when the request signal last at least 20 ms.
A
Button release allowed
20 ms
B
Time
Button pressed
C