Index Homing odd offset

How are you driving you motors?

Can you post your hal and ini files?

AFAIK homing on index does _not_ work with step/direction unless setup properly

Andy,
I'm using the 2nd to last diagram homing routine. It fails right after receiving the assumed index signal. I will try to attach or post the ini and hal files.

PCW,

Thanks for the info. I'm still on the same build, 2 axis lathe with DMM servo drives using your 7i85s 5i25 and field interface boards.
I have been running the drives step/dir for initial configurations to get things going but need to spend more time setting up for closed loop without joint following errors.

To use homing on index you must set up the stepgen in velocity mode and use encoder
feedback to close the position loop

Here is the hal file.

Here is the ini

The 2 files are not final.
On this configuration, I get the joint following error when I double the default 60 ipm setting to 120. It faults out around 70-80 ipm On open loop 300 ipm no problem.
Let me know if there is anything obvious in there to correct that and get the index homing to work for starters.
I know it's off topic, but while you are looking at my hal file, on the wish list is a limit component to ignore the jog increments above .001" so my mpg only uses the jog increments that are selected below .001" for movement. I have not been able to figure that out after looking at the limit1.9 manual that Andy sent me a link to while ago.
Also, The spindle has not been implemented. I probably will need help with that as well. The spindle motor encoder is wired to the 7i85s, A,B and index and wiring the outputs to spinx next.

To try and solve the following in closed loop error issue I would first try setting
the tuning parameters a little differently:


Set P to 1000 (for X and Z in the INI file)

EDIT: gradually increase P up from 50 until you get oscillations and then back off to about 50% of the value that caused oscillation

(1000 is suited for open loop which means almost 0 delay from command to result,
closed loop will have more delay from step command to encoder count so cannot have as high a gain)

You can use the calibrate menu option to set the PID values live

Set pid.x.maxerror and pid.z.maxerror to .005 (these are in the hal file)

To run at 300 IPM you will of course need to set::

MAX_VELOCITY = 5.0
(5 IPS = 300 IPM)
STEPGEN_MAXVEL = 6.0
(25% headroom)

For both X and Z in the INI file