Rockwell Automation 21G PowerFlex 750-Series AC Drives Reference Manual - Manual (Page 66)

66 Rockwell Automation Publication 750-RM001F-EN-P - February 2012
Chapter 6 Safe Stop and Safe Stop with Door Monitoring Modes
Figure 15 - Deceleration Monitoring
When deceleration monitoring is being performed, the speed limit monitored
during the Stop Delay P47 [Max Stop Time] must be less than the Deceleration
Monitoring Value or a Deceleration fault occurs. A Deceleration fault places
outputs in the faulted state, but allows the door to be unlocked when the
feedback signals indicate Standstill Speed has been reached.
Safe Stop Reset
The Safe Stop Reset (SS Reset) is a reset from the Safe State or from a stopping
condition to actively monitoring motion. The reset is successful if the SS_In
input is ON and no faults are present.
When an SS Reset is requested, all diagnostic tests that can be performed prior to
outputs being energized are performed prior to a successful SS Reset. If a
diagnostic test can be performed only when outputs are energized, the test is
performed immediately following the SS Reset.
Standstill Speed Time
Stop Delay
P47 [Max Stop Time]
(
Δv) = Deceleration Tolerance %
x Deceleration Reference
Speed: P51
Actual speed measured at the start of the Stop
Delay: P47 [Max Stop Time].
Stop Request
Speed
TIP To account for system overshoot and drive delay, choose
Δv and set P50 [Decel
Ref Speed] to the highest normal operating speed to calculate the Deceleration
Tolerance. Remember that P51 [Stop Decel Tol] parameter is a percentage.
ATTENTION: For all types of reset (automatic, manual, or manual monitored), if
a reset of the Safe Stop or Safe Limited Speed functions can result in machine
operation, the other speed monitoring functions must be configured to detect
and prevent dangerous motion.
IMPORTANT An SS Reset is not attempted if the Wait SS Cyc attribute is set (1), indicating
that an error, other than an invalid configuration fault or ESM_In input fault,
occurred.
The Wait SS Cyc attribute is bit 25 of the P68 [Guard Status] parameter.