ABB FSO-21, User Manual

Page: 113 / 540

Safety functions 113
Step Description
1 The SSE request is received (for example, from the I/O). The FSO activates the SBC
function (brake) and starts counters for times A and B. SSE active indication
SSE
output ( SSE.21 ) and STO output ( STO.21 ) go on.
2 After time C has elapsed, the SBC starts to brake the motor.
3 After time A has elapsed, the FSO activates the drive STO function.
4 After time B has elapsed, the FSO module defines the motor as stopped and the SSE
completed indication goes on. The acknowledgement becomes allowed as soon as the
SSE request has been removed (step 5).
5 The SSE request is removed.
6 After the acknowledgement, the SSE, STO and SBC functions are deactivated and the
control is given back to the drive, which controls the brake from now on. The
indications
SSE output ( SSE.21 ), SSE completed output ( SSE.22 ), and STO output
( STO.21 ) go off.