Products & Solutions
Optical Rotary Encoders
Magnetic Rotary Encoders
Hazardous Area Encoders
Non Contact Encoders
View All Accessories
Condition Monitoring Overview
OnSite System Overview
OnSite Analysis Tools
Condition Monitoring Applications
Fans and Blowers
Dust Collectors and Air Handlers
Cranes and Hoists
Aerospace & Defense
Off Highway Vehicles
Oil & Gas
Measuring Conveyor Speed
Measuring Angles with Encoders
Measuring Linear Distance
Measuring with Draw Wire Encoders
Measuring Position with Encoders
Service & Support Overview
Competitor Parts List
Discontinued Encoder Guide
Product Manuals & Installation Guides
Featured Crossover Guides
Avtron Encoder Crossovers
DRC Encoder Crossovers
Sick-Stegmann Encoder Crossovers
Allen Bradley Encoder Crossovers
Accu-coder Encoder Crossovers
BEI Encoder Crossovers
Koyo Encoder Crossovers
How to Choose Feedback
Encoder Issues and Troubleshooting
White Paper Downloads
Power Point Downloads
How to Specify a Resolver
Draw Wire Encoders
Hall Effect Encoders
Encoder Accuracy vs Resolution
Encoder Wiring Best Practices
Single-Turn vs Multi-Turn Encoders
How to Split an Encoder’s Signal
Troubleshoot Encoder Signal Issues
Encoder signal jitter is an inconsistency in encoder pulse shape in relation to another channel, often appearing as a backwards and forwards movement in the pulse. In the case of true signal jitter, the effect should show up on just one channel versus on all channels.
The channel that provides the trigger stays well behaved and the other channel appears to move back and forth, extending and contracting periodically. Triggering from the other channel will reverse the effect; the trigger channel remains static and the other channel appears to extend.
Encoder Signal Jitter Example on B Channel
This effect is typically caused by jitter internal to the encoder, which is introduced by the code disc being decentered. As the disc turns, the physical channels appear to move relative to one another. This affects the timing of the pulse streams, making the phasing between channel A and channel B change with every rotation. Frequently, signal issues categorized as jitter are caused by other error sources, so it is important to be methodical in the troubleshooting process.
Does the effect appear on only one channel?
Do the pulse edges appear to move back and forth?
Does the error change channels when the trigger is changed from one channel to the other?
Although jitter can be a serious issue, it is easy to confuse with other phenomena like interpolation flicker. It’s important to note that all encoders have some negligible amount of jitter as a result of the physics of the devices. The question to answer is whether the device is operating within spec. If it is not operating within spec, and if the behavior shown above appears, users should reach out to their applications engineering team to isolate the problem.