
01
Ed.
1999.08.03
Date
S.Hanyu
Name
Newly designed
Detail of modification
Subject
Spec.
Signal processing and parameter setting
for Machine Protection Function
at Power Failure
B-65162E/03-10
FANUC LTD
Page
5/ 7
2. Stop Distance Reduction Function at Power Failure
This function is to stop the feed axes in the equal time constant with the normal operation to prevent the
machine being damaged by over-running in case that the power failure occurs during the rapid traverse. It is
possible to stop the spindle motor under the control. To use this function some Sub Module R are necessary in
addition to Power Failure Backup Module. Refer to “Power Failure Backup Module Descriptions” (B-65162/03-
01, B-65162/03-08) about the number of Sub Module R.
2 -1 Feed axes stop control at power failure
Set the parameters of Stop Distance Reduction Function (Servo basic function), and set the
emergency stop signal (*ESP) of CNC to “0” when Power failure detection signal (*PFL) changes from
“1” to “0”.
Detect power failure
*PFL
*ESP
*PFL: Power failure detection signal.
Output from the connector CX16 on Power Failure Backup Module.
*ESP: Emergency stop signal of CNC
Signal address
CNC *ESP
FS15i X000 #4
FS16i, FS18i, FS21i X008 #4
FS0C X121 #4
Note) The signal operated by Power failure detection signal (*PFL) is CNC emergency stop
signal, not PSM emergency stop signal.
Parameter setting
(1) DBST: “1” (The stop distance reduction function is used)
(2) BRKC: “1” (The brake control function is used)
(3) Brake control timer: Set the value of more than rapid traverse time constant
Parameter number
CNC DBST BRKC Brake control
timer
FS15i, FS15-B No.1959 #0 No.1883 #6 No.1976
FS16i /18i /21i
FS16/18/20, Power Mate
No.2017 #0 No.2005 #6 No.2083
FS15-A No.1884 #1 No.1883 #6 No.1976
FS0C No.8X06 #1 No.8X05 #6 No.8X83
Refer to PARAMETER MANUAL (B-65150/03) in detail.