HURCO KMB-1 Control Update

Not only makes even more sense, but works.
Thank you sir, again.

Linuxcnc is running, well little by little.
I have the encoders counting and the DRO scale is calibrated.
I have the limit switches all tripping.
I have the main safety relay latching and tripping from the external button.
Next stop to get the safety relay to trip from the gui, then I plan to enable the servo relay, see if the axes can be moved by the gui, then study homing which looks like a whole mountain of mystery in itself.

Getting the ENA signal out to the original Hurco servo relay was problem as they draw 55mA. Solved by using a ULN2003 channel. Note that this needs to be done via a series 3k3 resistor and 1K resistor to ground.
Re the Estop.
I can trip the Estop relay, from the GUI, or pressing the Mechanical button, however, when I use the Mechanical switch, the gui doesn't register that the relay has tripped.
Is it possible to use the fact the estop terminal (OUTPUT0) is no longer conducting as a signal to change the GUI Estop status? If that's not picking myself up by my bootlaces...

Three axes moving. Not without a fight.
On enabling the servos, without me touching anything, the z axis would advance about 1mm, and trip out with joint follower error. Similar symptom to replacing an encoder and getting the a and b channels swapped. Took me too many hours to find in the heart of Tommy's tuning guide the answer, put a minus in front of the motor scale figure. (Required on all the axes.)
I've entered a default figure 20 for P and deadband.0001mm. Kind of surprised I cannot get it to error even at max jog speed.
Keep jacking up the P value, until it oscillates I guess, a job for another day.

I've found a spindle overload signal comes from the ancient VFD, 5v at similar level to the limit switches and encoders.
For the limit switches I am using encoder channels 3 and 4.
Analogue output 5 is for the spindle, and the spindle motor has no encoders.
Can I use one these unused encoder pins, say QA5, for this overload signal? Or is it out of bounds if the analogue side is used?
Thanks

Homing is now driving out to the limit switches.
I've set x axis (joint(0):-
HOME_SEQUENCE = 2
HOME_SEARCH_VEL = -100
HOME_LATCH_VEL = 10
HOME_USE_INDEX = YES
HOME_OFFSET = 5.08
HOME = 25.4
But not returning to the index.


Thanks

It helps if I spell HOME_SEARCH_VEL correctly.
So, pressing home, the axis travels to the minus limit, where is stops with an error.

I think the relevant hal lines are.:-

net x-home-sw <= hm2_7i92.0.encoder.03.input-a
(I have 5volt limit switches, so I have then connected to unused encoder pins)
net x-index-enable joint.0.index-enable <=> hm2_7i92.0.encoder.00.index-enable
net x-home-sw => joint.0.home-sw-in
net x-home-sw => joint.0.neg-lim-sw-in
net x-home-sw => joint.0.pos-lim-sw-in
Quite confused about why its hitting the limit switch as an end of travel, but not using that as the home trip, and returning to the encoder index.
Appreciate any thoughts.
Thanks

In fact there is nothing much wrong with the hal and ini entries,
HOME_OFFSET = 25.4
HOME = 0
I understand these better now, and to have the machine Home position at 0.0 25.4mm away from the limit switch after the encoder index has registered was my intention.
But even after I have tuned the axis I cannot get a successful home.
It has however stopped parking on the limit switch, but but can generate a big joint following error. The Rapid Halscope image, is at 6350mm/min and to me from what I've learned from the tutorial is pretty good.
I've set the HAlscope f-error at 5/DIV to match the tutorials, but wonder if that's correct for a metric setup
The Home image is the follower error up to the shutdown, which shows a massive figure that I cannot reproduced with the jog buttons even at max table speed. 
Not quite making sense to me yet.
I'd appreciate some comments.

In the  top plot, it looks to me like you have the maximum velocity faster the the drive can go
(so the following error rapidly increases when you reach the limit)

Normally you will need to set LinuxCNCs velocity limit to 80-90% of the machine velocity at 10V