Setting up 7i97t w idc26 bob

Are you sure you are flashing the current file?

The change is the PWM version It needs to be > 0 for Dither to be supported

What does

mesaflash --device 7i97t --addr 10.10.10.10 --readhmid

report?

I'm not sure i'm flashing the current file.

Yeah, that's the old file. not sure where mesact expects the files but you can program the new file with:

mesaflash --device 7i97t --addr 10.10.10.10 --write 7i97t_5abobd.bin --reload

run in the directory where the new file has been placed

Well that worked. No more dither error.
Thanks.

I don’t know where mesact expects the files either. I searched for the files in the file system with that name and replaced them. I know nothing about Linux so I’m sure made a mistake.
But if I ever need to flash again, I’ll know to use the command line in the directory with the file.

I am struggling trying to get my z axis hal setup. This is using a bob connected to a 7i97t.
The h bridge driver I am trying to use wants lpwm/rpwm, so I assume I need to use stepgen type 1 and velocity control.
I think this will make the 7197t's p2 expansion step and dir pins into up/down pins?
I'm sorta copying/converting examples but i get really confused between the differences between parallel port and mesa examples.
For example, looking in the linuxcnc manual, i should use something like:
loadrt stepgen step_type=1 ctrl_type=v
But for a mesa card, I shouldn't use loadrt, but use something like this instead:
setp hm2_[MESA](BOARD).0.stepgen.00.step_type 1
setp hm2_[MESA](BOARD).0.stepgen.00.control-type 1
Right? but control-type v gives me an error.

I am attaching my main.hal but I copied everything I think is relevant into justz.hal to hopefully make it easier to glance at.
The stuff with # are things I put in that I now don't think I need.
The z-enable is because the motor has a 24v brake clutch, but this doesn't seem to work either, although I haven't given much attention.
 

edit : Wrong advice Thanks PCW

A stepgen is not appropriate for driving an HBridge

The 7i97t_5abobd.bin firmware includes a PWM generator
with its pins brought out on DB25 pins 1 and 14 (HDR26 pins 1 and 2)

If you have a working 7I97t analog configuration, (with analog Z axis setup)
to adapt to your Hbridge, you would basically just change the Z axis PWMgen
number to 7 for the external P1 pwmgen, disable offset mode, disable dither,
and set the PWM output type  to 2 for up/down PWM



 

I kept looking at what is displayed in the terminal when linuxcnc starts.
I just did read readhmid and there’s the pwm, pin 1/14, plain as day.
Thank you for helping me despite my ignorance. You rock 
 

How would i set this pwm up for open loop?
I know this would normally not be done, but this motor doesn’t have an encoder and id like to experiment with using current sensing for probing and limits.

I originally tried mimicking the pid for a open loop stepper, but I don’t think there’s a pwmgen equivalent for stepgen.n.position-fb.
I next tried using sim_encoder, but i get mixed up pretty quick with that.

Should I spend more time trying to understand sim_encoder or is there a better approach?

I'm a little confused about how this is supposed to work as a Z axis
without some position feedback.

For a PWM driven motion axis, you would expect to have position
feedback fed to a PID component. This PID components output
would drive the PWMgen and force the motor to follow the commanded
position. Without feedback all you can really do is drive the motor in either
direction at a programmable speed.

I suppose you can use the plasma voltage for feedback when the torch is on
as a normal THC does, but when the torch is off you would have no idea
when the Z axis was (unless driven into the upper stop)