Pressbrake CNC Control Setup Questions

The backstop homes, but as it hits the index point it jerks rapidly before it goes to its home search velocity.

I start the control with the backstop close to the point where the home switch drops from high to low so that the encoder count starts close to 0. That way when homing applies the offset, it is minimal. The farther from the homing point, the longer the fast travel is.

I'll try and get a halscope screenshot starting off of the homeswitch.

Halscope screenshot, Starting on home switch:

 

Both starting on or off the home switch give the same rapid jerk.

Here is a halscope screenshot starting OFF of the home switch.

 

Could you add a plot of the commanded position?
Does the PID component have index-enable connected?

What is supposed to happen on homing to index is that the when index is
detected, the encoder position is set to 0.0 and index-enable is set false.
LinuxCNC watches the index-enable signal, and when it has a high to low transition,
it sets the commanded position to 0.0 to match the feedback position.

In addition, the PID component watches index enable so that any derivative
or feed-forward term calculations ignore the position step in its commanded and
feedback inputs.

After recent discussion on the mailing list, can I repeat this question? I would like to see where the problem is.

it looks like pid.1.index-enable is false before getting to the index.

 

are the pid connections wrong in the hal file? 



i'll do some more testing.

more testing: consistently pid.1.index-enable goes false, but pid.1.command does not set to 0.