drum cal
This command is available starting at version 1.09 of the drum software module.
The purpose of this command is to calculate and put into effect a correction
offset that will compensate for dead-band drift within the drive amp (in certain specific cases).
This command applies a torque ramp to the drum and measures the point at which movement occurs.
If that value of torque is above the drum friction (dfrict) then it sets the deadband offset
(doff) to the measured value minus dfrict.
The nvs needs to be saved to make the value permanent. The torque numbers displayed & dfrict
& doff are all in half-microseconds (which is proportional to torque.)
On drum module 1.11 and older, if the current value of doff is greater that zero then
doff is not updated by drum cal. Manually set doff to zero if required.
Encoder Required: For this command to function a working encoder is required including the
index pulse.
The torque numbers displayed & dfrict & doff
are all in half-microseconds (which is proportional to torque.)
See procedure to set dfrict, under nvs dfrict on the nvs page.
All
drum cal
This command is available only in drum module versions 1.09 and greater.
Before actual drum calibration is attempted, the DRUM CAL command tries
to get the drum to "settle". This is done by releasing the dynamic break
and setting the drum drive zero. Depending on the condition of the drum
amplifier, one of the following three things can occur:
The drum will turn slightly then stop (i.e. reach equilibrium)
The drum will continue to turn slowly for an indefinite time
The drum will accelerate
Case 1 is usual. The calibration attempt will proceed normally after this.
Case 2 and 3 are error conditions. In these cases the dynamic break will be
applied and the calibration will fail because the drum wont settle. This
may be as result of negative deadband in the drum amplifier. Case 2 occurs
if the drum does not stop within about 15 seconds. Case 3 occurs if the
speed of the drum becomes greater than 30 RPM.