Rockwell Automation 2090 Ultra3000 Servo Drives Integration Manual - Manual (Page 141)

141 Publication 2098-IN005C-EN-P — March 2008
Appendix
C
Minimizing the Effects of
Feedback Signal Loss
Introduction This appendix contains information on how to reduce unexpected
motion as a result of feedback signal loss.
In the event of feedback signal loss, unexpected motion may occur.
When the feedback signal is lost, the position feedback remains
stationary, regardless of the actual axis position and the drive
command position. In an effort to compensate for the discrepancy
between the position feedback and the drive command position, the
drive attempts to maintain axis motion, which quickly results in an
increase of position and velocity error. Once the position error
reaches or exceeds your specified limit, the drive indicates an Excess
Position Error (E19) to alert you of the fault condition. Similarly, an
Excess Velocity Error (E24) is indicated once your specified velocity
error limit is reached or exceeded.
These system fault indications are intended to alert you of the fault
conditions and to aid you in safely bringing the system to a stop. By
optimizing the sensitivity threshold and the response time of the drive
to position and velocity error fault conditions, you can quickly and
safely disable the drive and be alerted by a fault indication to proceed
with other safety measures when the feedback signal is lost.
Topic Page
Introduction 141
Setting Position Error Limits in Ultraware and RSLogix 5000 Software 142
Setting Velocity Error Limits in Ultraware Software 144
Configuring Fault Actions in RSLogix 5000 Software 145
Position and Velocity Error Limit Adjustment Example with Ultraware Software 147
Position Error Limit Adjustment Example with RSLogix 5000 Software 154
Additional Methods 166
ATTENTION
To avoid personal injury or damage to equipment due to
unexpected motion, you must configure the associated motion
system parameters and attributes to minimize the effects of
feedback signal loss on the system.