Encoder Limit Error

Problem

If the machine is not operating and the” information light” next to the power button and the firmware LED on the logic board flashes with the following eight-bit pattern as described here:

Where 0 indicates a short pulse which is 1/4 second and 1 indicates a long pulse which is 1 second long.

This will be displayed in MotorScope as a “Limit Fault”. This means that the machine detected the encoder limit during normal operation (not during a volume find operation). Normally, there is a margin between the usable volume and the encoder limit.

Solution

The following items provide step by step instructions on how to break down the cause of the issue:

1. This can easily occur if the limits are moved or replaced. In this case, a new volume calibration needs to be run.

2. This can occur due to linear encoder counting issues. These may be accompanied by Following Error Faults or Encoder Synchronization Faults.

   • Check the color of the encoder interpolator (Tonic Interface) to ensure it is Green, Blue, or Purple across the travel (it is okay for the color to change across the travel).

     • If not, realign and rephrase the encoder readhead.

3. This can occur due to egregious drive issues.

   • Check that there is no slop or slippage in the drive.

Open

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