Variable Sls With Ramp Monitoring - ABB FSO-21 User Manual

140 Safety functions
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Variable SLS with ramp monitoring

In Variable SLS with ramp monitoring, the ramp according to which the drive
decelerates the motor to different speeds is monitored using the ramp monitoring
method (SAR1 parameters of the FSO module). Drive or SAR1 parameters define the
deceleration ramp. If the motor speed is accelerated, drive parameters define the
acceleration ramp and it is not monitored.
For configuration, see section
on page 299.
Motor speed
B
1
2
A Variable SLS trip limits (parameter
B Response time (depends on system configuration, see page 437)
Ramp monitoring limits or Variable SLS trip limit (A)
Step Description
1 The Variable SLS request is received from the safety PLC (for example, 70%). The
FSO sends a request to the drive to ramp down the motor speed to the new speed limit.
2-3 After time B has elapsed, the drive starts to ramp down the motor speed. SAR1
parameter 200.112
according to SAR1 parameters (SARx.21, SARx.22).
Note: If parameter
Note: If the motor speed does not follow the ramp, the FSO activates the STO function.
The FSO starts the SLS monitoring when the motor speed is in the middle of the new
SLS limit and the SLS trip limit (see also section
started on page 319).
3 The new motor speed has been reached. The Variable SLS indication (parameter
SLSx.51) goes on.
How to configure Variable SLS with ramp monitoring
B
A
3 4
5 6
SLSx.43
defines the deceleration ramp. The FSO starts to monitor the ramp
200.112 has value 0, the drive (parameter 23.23) defines the ramp.
A
B
A
7 8
9
and the scaling values set in the safety PLC)
How to fine-tune when monitoring is
Time
10
varSLS request
varSLS status
& indication
SAR1
monitoring