Safe limited speed with door monitoring mode – Rockwell Automation 21G PowerFlex 750-Series AC Drives Reference Manual User Manual
Page 81
Rockwell Automation Publication 750-RM001F-EN-P - February 2012
81
Safe Limited Speed (SLS) Modes
Chapter 7
Safe Limited Speed with
Door Monitoring Mode
When properly configured for Safe Limited Speed with Door Monitoring, the
safety option performs Safe Limited Speed (SLS) monitoring functions as
described in
in addition to the Safe
Stop functions as described in
In addition, the safety option verifies through monitoring the Door Monitor
input (DM_In) that the safety option controlled by the Door Control output
(DC_Out) is in the expected state. If the door is monitored as opened when it
should be closed, the safety option initiates the configured Safe Stop Type.
The Door Monitor input (DM_In) is ON when the door is closed and OFF
when the door is open. The DM_In input must be ON (door closed) whenever
Safe Limited Speed monitoring is inactive (SLS_In is ON, meaning the circuit is
closed). The DM_In input must also be ON (door closed) during a Safe Limited
Speed Monitoring Delay [LimSpd Mon Delay]. A Door Monitor fault is a Stop
Category fault, which initiates the configured Safe Stop Type.
If Safe Limited Speed Monitoring is active (SLS_In input is OFF) and the safety
option has verified a safe speed condition, the door can be unlocked and opened.
You can monitor the door’s status with or without the door control (lock/
unlock) function. When door control logic is set to lock, it prevents personnel
from entering the hazardous area when the machine is not at a safe speed or at
Standstill Speed.
Figure 20 - Timing Diagram for Safe Limited Speed (SLS) with Door Monitoring Mode
ATTENTION: Make sure that an open door does not result in a hazardous
situation.
If a Safe Stop Type is initiated or a fault occurs while the safety option is actively
monitoring Safe Limited Speed, door control remains unlocked. The safe state of
the SLS_In input may allow the door to be unlocked.
SLS
Request
P55 [Safe Speed Limit]
Speed
Time
SLS Monitoring Delay:
P53
Safe Limited Speed
Active
SLS Fault
Acceptable Speed Range
SLS Request
Removed
Door can be opened.