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You would need the stepspace defined as well
(I think the default times are quite long which may
prevent getting all the way to 25 KHz)

The direction timings don't matter

You can use maxaccel if you wish to change the spindle
accel and deccel times. Setting the stepgen Maxvel to 25000
will prevent it from ever generating more than a 25 KHz
frequency even if given a bogus spindle speed command.
 

try

mesaflash --addr 10.10.10.10 --device=ETHER --sserial

Note that you need to set the pwmgen to offset mode,
and for the 7I97T, use a 75 KHz PWM frequency with
dither enabled.

Here is an example config file that has the PWM setup

freeby.mesanet.com/basic7i97.zip
 

Yes, the servos have relative encoders. The previous owner of this unit had always planned to upgrade the control so that the encoders would be useful. It makes sense to me as well.

Since the 7I76e variants are not in stock right now, and my other machine that I will eventually build is a stepper motor machine, would it make more sense for me to buy one of the analog boards that are in stock right now? I suspect that some more snooping around the Mesa store might be in order...

Pardon my ignorance... Based on your comment I presume that the servo tuning is stored in the servo drives?

I have had the understanding that I DO want the LinuxCNC feedback loop in order to make a [more] closed loop system which is more better than having the control completely blind to the position (or loss of position) of the motors.

Hello,

my Mesa cards for the LCNC retrofit just arrived. I'm using 7i97t as the main card which is connected to the pc with ethernet. After some trouble updating Mesaflash i got that connected to the PC fine and the pins already work (in Hal show with an MPG encoder).

For the hal file I wanted to get a starting point by follwoing the Pncconf wizard and then editing the file as needed. The pncconf however has no infos on the 7i97t and I need to use the discovery function. THis also works and the card is detected. All seems well and I can even configure the Pins on my 7i84d which is connected through sserial to the 7i97t with a chopped ethernet cable connected as per 7i97t's instructions. When I start LinuxCNC with this config however, I get an error that a pin on the 7i84 is missing. If I don't configure the pins on 7i84d in Pncconf LCNC will launch but halshow won't let me see the I/Os on the 7i84d, only 7i97t.

when I type "
mesaflash --addr 10.10.10.10 --device=ETHER --readhmid
into the terminal i also cant see the pins on 7i84d. both cards have power and the status LEDs are indicating ok. 

Do I need a different firmware on the 7i97t?
Any help is greatly appreciated.

net remote-rapid-to-home halui.mdi-command-00 <= pyvcp.rapid-to-home

in the main hal file, I have 

[HALUI]
# add halui MDI commands here (max 64) 
MDI_COMMAND = G0 X0 Y0 Z0
MDI_COMMAND = G0 X20 Y0 Z0


if I change halui.mdi-command-00 to halui.mdi-command-01
my custom button will execute the saecond line.

What if I have more g code lines and I want to execute all of them?

Good day

Philip

Do the servo drives have encoder outputs? Al Yaskawa i have worked with do have them, so since you have 7i76E just add a 7i85 or 7i85S for encoder feedback and you get the best of both worlds, easy tuning and position control even when drives are disabled.

Thanks Aciera, that looks like it works. I'm unable to commit to a full run right now, but I added your comment, raised z=0 so I was cutting on air, and the program ran and started cutting (then I stopped it).

Have you tried adding '(AXIS,stop) ' to the top of your gcode?
This should prevent the preview from loading and might help with very large programs.

I would think that leaving it step/dir would be the easiest path
and would require few wiring changes. It also would not require
changing the drive setup, tuning the drives or tuning LinuxCNC's
feedback loop.

The only real advantage to an analog setup is that you can disable
the drives without losing position.

I have a gcode program much larger than anything I've run before. It has about 800k lines.
I'm on Linux Mint 20, using linuxcnc 2.8.4-76-g6082f1df7 and axis.
When I run the gcode, I have several issues:
1. The preview window in axis is garbage (see axis_screen.png).
2. When I start the program, I get a popup error (see first_error.png)
3. I tell it to 'run anyway' and get joint errors (see second_error.png), specifically the X axis on line 12. In the first image, you can see line 12; nothing odd there.

I searched for any x or y command in the entire file that has more than one digit in front of the decimal place (X19.0 would be found, X9.0 would not). Nada.

I loaded a 50 line gcode program I use for surfacing. It is configured to surface the same size piece of material as the very large program. The surfacing program runs with no problems.

Please advise,
Steve

I've got a 5' x 10' CNC router with a failed Mach 3 control. It has Yaskawa Servos (SGMGH-09ACA61) and was set up for step/dir with an ethernet smooth stepper. It was "open loop" with that control. It has four motors for the 3 main axis and a 5th motor for a rotary axis. I might not use the 5th axis but I do have a crazy idea for an automated dust collection "axis" that would probably use stepper motors. 

I have a Mesa 7I76e that I bought several years ago for another machine that has yet to be completed and I think this would be my fastest/easiest control to drop in but would still leave me open loop to the control. Instead I've been thinking of running with analog servo signals and the encoder feedback into LinuxCNC using a 7I92TF with a 7I77 or a single 7I97T. It seems the 7I97T might be a bit light on general I/O since the machine has an ATC spindle and several other pneumatics that need to be controlled and sensed so I'm leaning towards the former combo. 

Any suggestions wrt to Mesa card availability and the advantage of using analog vs step/dir in this application? 

 

1. I'm using Tormach's firmware for the 770 configuration which has the following for the spindle:

#    Mill Function   Pin#    I/O     Pri. func    Sec. func    Chan      Pin func        Pin Dir
#
#    Spindle Speed    1        0     IOPort       StepGen       4        Step/Table1     (Out)

2. By default the PathPilot uses stepgen mode 2. I think I'm confused as I read they use PWM and I need a step/dir which made me think I needed to use stepgen mode 0. I'll switch back to mode 2. These are the other default values:

position-scale 1.0
maxaccel 0
stepspace 0
steplen 10000

I'll change the steplength and step space to 1000 and position-scale to 7.163. Does maxaccel matter? The PathPilot hal also appears to be missing dirsetup, dirhold and maxvel which were included in the hal generated by Pncconf.
 

Chris thank you, you've answered all of my questions and suspicions.


 

1. What firmware are you using on the 7I92?
(suggest C11, not C11G) as it has a step only output
on pin 14.

2. Typically you would use stepgen mode 2 for this type of application
(since it generates a square wave). In addition you need to set the
steplength and step space to small enough values that they do not
interfere with the maximum frequency (say 1000 each)

If the full scale RPM is 3490 RPM, the step scale would be set to 25000/3490
= ~7.163