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Step/Dir index support with Mesa hardware does not need any
programming, just the correct firmware and a minor hal change:
 
Replacing the encoder index  enable with the stepgen index enable.

It's likely possible to do this with programming but that has the disadvantage
of having an index detection uncertainly of a thread period.

Does you current setup have inputs available for index inputs?

Thanks for the answers. As I understand it, the differences in the answers mean that there is no single solution in the system. Why is such a question even raised? Systems with hybrid or servo drivers already cost almost the same as stepper motors. Of course, if a person does not use Sinumerik, Fagor, Fanuc, he is looking for a way to save money. Therefore, the 7i92 + 2 x ABOB combination is simply an ideal solution for the price of quality. And to make your own hobby machine with perfect homing, and even at a low price, it is impeccable.
It is also clear that this functionality can be implemented programmatically. I will also try to find the firmware you are talking about. Does it mean that in the firmware the encoder index is untied from the counter?
I will try to implement this using the GPT chat, but I do not think that I will succeed with my little knowledge of code programming.
With respect

That's what I figured to try first. Wiring it up to make a 5v Field B right now and then I'll move the MPG over and try it
Thanks again,
M

There's no current way to support differential inputs on the 7I84/7I84U
I would just use a differential encoder single ended (just use A+,B+)

Thanks for that clarification (never would have figured that one out)
Any guidance on the change to mode 2 creating two separate A/B single ended encoders or one A+/A- B+/B- differential ?
Thanks
M

That looks correct except you do not change the number of encoders:
"num_encoders"  as this only applies to high speed encoders, not sserial devices.

Question. If I use speculative memory access via _mm_prefetch (SSE instruction), does it affect the Linux CNC kernel? I am using this on RAW L2 Zero Copy sockets. I ran it, it seems to work, Axis (Linux CNC) doesn't break. Are there any restrictions on what can be used programmatically when writing drivers for Linux CNC?

Question 2.

Trying to free up the high speed encoder function on my 7i96s by moving the pendant wiring all over to a 7i84u and might as well move all of the other pendant wiring over at the same time.

I read that if I run the 7i84u card in "mode 2" there are 2 spots on TB2 that set up as encoder channels (inputs 16-19)
Would that be two separate A/B single ended encoders or is that one A+/A- B+/B- differential like I have on the 7i96s ???   The pendant MPG has differential output

it also says that the thresholds automatically go to 2.5v to be compatible with MPGs.
Is that's regardless of field power level or not?

Currently I have Field A and B both at 24v, my original thought was  to use the split field power option and have field A be my 24v and move all of the axis selection, jog rate, e-stop pendant inputs  as well as the existing prox limit/home and output onto TB3
Then make field B into 5v and move all of the pendant wiring over from the 7i96s to TB2. I could tap into the VFIELD power input block TB1 for my power and ground for the pendant. I end up with a pile of 5v IN/OUTs that I'm not sure what to do with but maybe later


For switching to MODE 2, software selectable so from what I understand:
what I currently have in the HAL
loadrt hm2_eth board_ip="192.168.1.121" config="num_encoders=1 num_pwmgens=1 num_stepgens=3 sserial_port_0=0xxxxxxx" 

changes to:
loadrt hm2_eth board_ip="192.168.1.121" config="num_encoders=2 num_pwmgens=1 num_stepgens=3 sserial_port_0=2xxxxxxx"  



Anyway, looking for any input before I blow up my second 7i84u
Thanks





 

Oh, I did not realize that there is a pcnconf utility. I used stepconf for my old machine, so hopefully this will work as well.
Deleting all the estop latch stuff did not work.
I will give pncconf a try next week.
Thank you for your help so far!

Not sure but something about the estop latch is is not working.

I would probable delete all the estop latch stuff as it's really not
needed here.

You might also be better off starting with a pncconf configuration


 

So ive tried the new repo code and it still hasnt enabled dc-phase or shown any value for PLL-ERR or PLL-out except 0.

Im not sure if i plotted it correctly because i couldnt find the servo thread in halscope (is it servothread.time? ). However, please see attached image for pll-err and app-phase like requested.

Sync0Shfit was changed to 300000 aswell like you suggested

Mesa Hostmot2 supports homing to index on step/dir systems.
It requires firmware that supports step/dir Index (normally
such firmware has "SDI" in it's name). It also requires one free
input per step/dir channel for the index signal.

This allows homing to index  and spindle synchronized motion  on
step/dir systems without encoder feedback to LinuxCNC.

I will give it a shot. Thanks for the Feedback regarding my files 

Thanks! Unfortunately I don’t have time to test this today, but will do it tomorrow at the earliest or Monday at the latest.

@ Atsu

I made a small change in my repo, get the new code, and make a new build then test, see if pll-err and pll-out get a value this time.