Troubleshooting 4-5
F91 Encoder Loss Requires differential encoder.
One of the 2 encoder channel
signals is missing.
1. Check Wiring.
2. If P038 [Speed Reference] = 9 
“Positioning” and E216 [Motor 
Fdbk Type] = 5 “Quad Check” 
swap the Encoder channel inputs 
(see page 1-18
) or swap any two 
motor leads.
3. Replace encoder.
F100 Parameter 
Checksum
➁
The checksum read from the 
board does not match the 
checksum calculated.
Set P041 [Reset To Defalts] to 
option 1 “Reset Defaults”.
F111 Enable 
Hardware
DriveGuard Safe-Off Option 
(Series B) board is installed and 
the ENBL enable jumper has not 
been removed.
1. Remove the ENBL enable 
jumper.
2. Cycle power.
DriveGuard Safe-Off Option 
(Series B) board has failed.
1. Remove power to the drive.
2. Replace DriveGuard Safe-Off 
Option (Series B) board.
Hardware Enable circuitry has 
failed.
Replace drive.
F122 I/O Board Fail
➁
Failure has been detected in the 
drive control and I/O section.
1. Cycle power.
2. Replace drive if fault cannot be 
cleared.
(1)
See page 4-1 for a description of fault types.
No. Fault
Type
(1)
Description Action