Applies to

• All

Error number

Description

Causes

• Obstruction preventing drum rotation (most probable cause)
• Incorrect drum parameters
• Drum acceleration parameter(s) set too high
• Hall sensing of motor faulty
• Dirty encoder disk (Creo encoder)
• Verbose level set too high (5080 and 5880 engines)
• Faulty or misaligned encoder electronics

Solutions

Verbose level set too high

The verbose level determines the types of messages that are reported to the diagnostics monitor. Some systems have difficulty dealing with this additional communications throughput.

Symptoms & Verification

Occurs intermittently particularly when multiple plates are queued. Setting verbose level higher increases frequency of occurrence.

Phone fix

Set verbose levels to min. values: set verbose all 0. To turn the verbosity off on modules whose active value is zero. Individually type set verbose xxx 0 to set the verbose of module xxx to 0 for modules with higher verbose settings experiencing difficulty (drum). The set verbose all 0 command will not override active settings of the individual modules (value of 1 is generally okay).

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Drum acceleration parameter(s) set too high

Symptoms & Verification

Check drum velocity acceleration and position acceleration values and as below.

Phone fix

Alter NVS parameters for velocity acceleration and/or position acceleration:

• set drum vacc 10 (3244)
• set drum pacc 6 (3244)
• set drum vacc 7 (5080,5580)
• set drum pacc 5 (5580)
• set drum pacc 2 (5080)

Reduce further if problem persists. Note that smaller values of the parameters will increase machine cycle time.

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Dirty encoder disk (Creo encoder)

Symptoms

May be accompanied by errors such as: “Velocity error -drum rotation blocked or PID gain settings wrong”, “Timeout on velocity settling”, “Timeout on velocity acceleration.” or “Drum Hall velocity does not match encoder velocity to within tolerance.”

Phone fix

Have operator inspect encoder disc for foreign objects or dirt. Clean the encoder disk.

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Incorrect drum parameters

Symptoms

May also be accompanied by other errors such as: “Velocity error -drum rotation blocked or PID gain settings wrong”, “Timeout on velocity settling”, “Timeout on velocity acceleration.”

Phone fix

Use the command set drum to compare the saved values to the defaults.

On Trendsetter TS3, TS4, and TS8-based machines (3244s and 3230s), the error may be caused if the drum tpr (encoder tach ticks per rotation) parameter is set incorrectly for the encoder.  In recent firmware releases, the default value has been changed to 5000, which is correct for the shaft-mounted Heidenhain encoder. However, the correct value for the Creo encoder is 9000.

On VLF drums, the defaults are for 5080 engines. For the 5880 drum, check the parameters on Default values for NVS drum parameters per engine size. If the error occurs during plotting, check the velocity control parameters. If the error occurs during loading/unloading, check the position control parameters are optimized for the published design drum belt tension. Earlier machines may have slightly customized parameters.

Do not overwrite the NVS drum values without recording them first.

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Faulty or misaligned encoder electronics

Symptoms & Verification: May also be accompanied by other errors such as: “Velocity error -drum rotation blocked or PID gain settings wrong”, “Timeout on velocity settling”, “Timeout on velocity acceleration.” Cleaning the encoder disk does not improve situation.

Fault may appear or disappear only when card cage is pivoted out. Failure of the encoder cable may cause this error message.

Phone fix: None

Site visit: Check the encoder, Align the encoder. Replace faulty encoder cable, or replace faulty encoder if necessary.

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Obstruction preventing drum rotation

Symptoms

Idling the drum (using the drum idle command) and rotating by hand will show where the obstruction occurs. Drum rotation forwards, backwards, and at any speed will be affected.

Phone fix

Ask operator to clear obstruction preventing the drum from rotating. Check for plates buckled between drum and engine frame casting, dropped clamps, etc.

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Hall sensing of motor position faulty

Site visit

Drive amps with hall isolation boards (See Identifying Drive Amps with Hall Sensors.)

1. Check to see if there is 5V to the Hall Isolation Board inside the drive amp. Check J3-8 and J3-5 on the drive amp.
2. The Hall sensor cable from motor to drive amp (J3) may be faulty. Rotate the drum slowly by hand and monitor the sequence of yellow LEDs. See Normal LED sequence on VLF or Normal LED sequence on 3244.
3. The ribbon cable from J2 on the drive amp to J6 on the back of the card cage backplane may be pinched or faulty.

NOTE: Refer also to Understanding Dependancies of Hall Sensors and Encoder.

See also

• General VLF drum drive, encoder, and PLL troubleshooting
• Main Drive Amp wiring, VLF
• Main Drive Amp wiring, 3244
• Firmware error messages 6022, 6023