Rockwell Automation 21G PowerFlex 750-Series AC Drives Reference Manual - Manual (Page 76)

76 Rockwell Automation Publication 750-RM001F-EN-P - February 2012
Chapter 7 Safe Limited Speed (SLS) Modes
If the measured velocity exceeds the Safe Speed Limit, an SLS fault occurs and
the configured P45 [Safe Stop Type] is initiated. An optional P53 [LimSpd Mon
Delay] can be configured to delay the start of Safe Limited Speed monitoring.
Safe Limited Speed monitoring is requested by a transition of the Safe Limited
Speed input (SLS_In) from ON to OFF. When the SLS_In input is ON, the
safety option does not monitor for Safe Limited Speed and the measured velocity
can be above or below the Safe Speed Limit.
If you configure a P53 [LimSpd Mon Delay], the delay begins when Safe Limited
Speed monitoring is requested by the SLS_In transition from ON to OFF. The
safety option begins monitoring for Safe Limited Speed when the delay times
out. If system speed is greater than or equal to the configured Safe Speed Limit
during Safe Limited Speed monitoring, an SLS fault occurs and the safety option
initiates the configured Safe Stop Type.
Figure 18 - Timing Diagram for Safe Limited Speed (SLS)
ATTENTION: If the Reset Type is configured as Automatic, Safe Limited Speed
monitoring is disabled when the SLS_In input is turned ON and the machine
operates at its normal run speed. Make sure that the SLS_In input cannot
transition to ON while someone is in the hazardous area.
SLS
Request
P55 [Safe Speed Limit]
Speed
Time
SLS Monitoring Delay:
P53
Safe Limited Speed
Active
SLS Fault
Acceptable Speed Range
SLS Request
Removed