Error Message:

DRUM: Timeout waiting for TPU hall sensor PW measurement

Applies to:

• All

Service Information:

This error indicates that it took too long for the firmware to see any pulses coming out of the drum motor's hall sensors. Remember that there are two methods to measure the drum speed: the encoder disk on the side of the drum, and the Hall effect sensors mounted inside the drum motor. The Hall sensors are only used to verify the encoder operation for safety reasons, so this error message will only show up during machine initialization or certain diagnostic commands.

Either the drum never turned enough to get a hall speed measurement, or there is a problem with the measurement circuit itself. Incorrect drum NVS parameters, mechanical blockage, or a faulty drum drive amplifier could all prevent the drum, from turning. A faulty drum motor, cables, drum drive amplifier, or MPE board or cabling between these (even back plane) could prevent the hall speed from being measured.

Operator Action:

There is a problem with the drum motor and/or drive mechanism. It is probably an intermittent problem, and should only show up during machine initialization shortly after the machine has been powered up.

Click on RESUME to try initializing the system again.

Make sure that the clamps are all in their appropriate positions and that there are no obstructions to drum rotation.

Cause:

• Incorrect drum NVS parameters. Make sure all the drum gain parameters (prop_gain_vel, integ_gain_vel, etc.) are all equal to, or very close to, their defaults.
• Mechanical blockage preventing drum rotation.
• Fuse blown or power supply failure. NOTE: there are 2 sources of power into the drum amp, one powers the logic (if any led inside the drum amp are on then that one is okay). The other provides power to the motor drive circuitry. There is no visible indication that this power is good or bad, except that the drum will not even attempt to move, bump, or make any sound when you type 'drum init'. Measure Logic power on pins J1-1 & J1-2 and Motor power on J1-3 & J1-4.
• Loose cables anywhere in the drum system. Any of the cables to the drum or drum amplifier could cause this error. Most commonly the hall sensor cable from the motor to J3 on the drive amp, the ribon cable from J2 on the drive amp to J6 on the backplane, or (newer systems) the 5V power into J3 on the drive amp.
• Faulty drum amplifier. See the "Drum Drive Amplifier Troubleshooting Guide" for more information.
• Lots of conducted electrical noise on the AC input lines to the machines. Check for secure AC connections and things like arc welders on the same circuit.
• Bad MPE board. (rare)

See Also:

• Other: Troubleshooting information