Long Name:

Applies to:

Description:

Nominal starting friction for a given drum servo system. This parameter is used during drum calibtration. If a drum calibration is successful, this value is subtracted from the drive value required to move the drum from a stopped condition. The resulting value will become the drum nvs parameter "doff".

Type:

Default:

• 33 (VLF)
• 15 (3244)
• 0 (Trendsetter NEWS)

Range:

• 0 to 50

Notes:

Procedure for setting dfrict.

• WARNING: high voltages may be present.

1. Connect a volt meter between any two phase outputs from the drive amp J4 (eg pin 2 - pin 3).
2. enter "Drum idle"
3. enter "set drum doff 0"
4. enter "drum torque 0"
5. The Voltage should be below 4V,
6. if not enter "drum torque 4" if the voltage goes up then the drum amp deadband too narrow (or negitive) to perform this procedure and should be replaced or calibrated anyway.
7. enter "drum torque <x>" repeatedly where x is increased by one at a time, until the voltage increases by >30% (typically >10V). (No more than torque 40 should be required) Note: The voltages that you read are dependent on the drum position, if you susspect that the voltage is higher than you expect then rotate the drum a bit by hand.
8. This value of torque is the true dead band.
9. enter "set drum doff 0" and "set drum dfrict 8" for 3244 and "set drum dfrict 8" for VLF This is an impirically determined deadband that the PID likes to see, it seems to prefer some deadband over a perfectly calibrated system.
10. Enter "drum cal"
11. Enter "set drum doff" to read the new value of doff, then set dfrict to (doff minus true_dead_band) using "set drum dfrict <#>"
12. enter "set drum doff 0" and "drum cal"
13. save settings using "nvs save drum"

For non-VLF Trendsetters with new 10A drum drive, this value should be set to 0. These machines will have the "sys hdp (high_pwr_drives_inst)" parameter set to 1.

Partition:

See Also: