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Hello,

I am using the 7i95t_1pktv2d.bin firmware for my Maho MH600T for controlling the spindle VFD. After I got the Modbus communication to the spindle working I started getting following errors, and this is still without using encoder feedback. There are jumps in the stepgen.xx.position-fb while everything is idle. I condensed the setup as much as possible to try to pinpoint the issue, and this is outlined below.

Using 7i95t_1pktv2d.bin firmware:
I use this minimal test.hal which I run with "halcmd -f test.hal":
With this maho_vfd.mod:
I get these jumps in hm2_7i95.0.stepgen.00.position-fb:
 

Currently I don't have the VFD connected, and the jumps occur every second plus some. This occurs more frequently with the VFD connected and communication working. I imagine the jumps occur on every Modbus request. Strangely enough, I don't see the issues if leave the num_stepgens undefined for hm2_eth. And I could do just that and go ahead with my life. But I fear this will come back to bite me if I do.

Any ideas what may be causing this? Some problem with my setup? A bug in the Mesa driver or firmware?

It is a heavy gantry, so adding 10-15KG of other stuff will not change much in mobility, so yes, mount everything on the gantry, including the PC. You do not want to run 15 meters to press ESC when needed!
Also, plasma so a lot of interference, and shorter wires help a lot in mitigating that.
Use existing cabling, usually very high quality and good shielding.
Here are some ideas
forum.linuxcnc.org/show-your-stuff/47357...sma-cutting-machines

Cr@p forgot to update this, finished the second one and in production use daily.
There was a change in the meantime, those are not 2 separate machines anymore, when moved from the other shop here, the owner had the great idea of having 2 gantries on one set of rails, so now it is a dual gantry machine, both sides can do 6X2.5M but not at the same time, one can do 6 while the other can do 2X2.5M at the same time, can be done from both sides as needed.
Will take some pictures next time i am there, it is closer to me now, about 2KM.

If i was to mount computer with controller to gantry would you recommend going with a sealed industrial fanless type computer I found a few on ebay for a couple hundred bucks. My last plasma table is a 4x10 I built with mach 3 and windows 7. I found the operating system to be highly unstable computer would crash or freeze, and I seen what kind of damage was done by the plasma dust. My other concern would be for shielding I here that these style of computers have a increased protection against rf interference and I know that the ht2000 will put out alot compared to my cheap everlast 102i blowback style. There is a few features I would like to have aswell on the Linux cnc side of things do you know if I can set up plate centering? Possibly amperage adjustment remotely. Do you have any other recommendations for scripts I can add to really trick this puppy out. I am new to linux cnc but trying to obsessively learn as much as I can, it seems like the best option open source.

Network latency is a Linux driver issue, it is NOT a LinuxCNC nor Mesa issue.
Computer latency is hardware issue, again NOT a LinuxCNC nor Mesa issue.
There is no bottleneck, your hardware will give up way before Mesa or LinuxCNC does, granted you do not have a 60000RPM spindle with over 2000PPR encoder, as that is 8MHz.
Still, i know some Mesa boards can do 10Mhz, so that is 2500PPR on 60000RPM.

Do you have any recommendations for wiring this whole thing? Should I mount the controller with the drives on the gantry itself? Or do I run wires threw the cable chain from controller to drives. I have concern the ht2000 will put out alot of high frequency interference. If I keep the original motors and drives I would like to keep atleast the drives mounted to the gantry so I can use the original wiring that is rf sheilded. Is there any parasitic loss on long distance runs that should be avoided by mounting controller to gantry. I think I would prefer not to mount the computer to the gantry it seems dangerous to me, but I might require a long range or wireless pendant otherwise. Maybe it's better to keep it all on the gantry. I still have not decided. Do you have any recommendations for sources for high rf sheilded cable? And what is your preferred type of wire. I've used alot of cheap wire before and had it corroded apart on other projects. Leading to endless wiring issues, I am building this machine In hopes I will run it often I want reliability and my shop is a hard atmosphere for a machine lots of dust and humidity/water from leaks.

I get greeted with either of these two screens when i try to boot up my machinee. its a fresh install of linuxcnc 2.93 on a raspberry pi 4 cm4 and a 7i96s, i have tried with other realeses but the issue remains the same. if it loads in to the program thee error messages pops up after a few seconds so not instant. Does anyone maybe know why or could point me in a direction because now im completly lost

Yes, yes and oh yes!
I like your idea of the combo, go for it.

Basically I understand that Mesa FPGA cards can do upto few MHz.

But there is constrain in terms of computer latency and network latency. There may be others also, I am not aware.

I want to know those and decide what is the bottle neck value of step pulse rate that I can use?

So your recommending the mesa 7i96s a 7i85 and a 7i83 and THCAD and I could use the stock motors see if they work with this combonation of cards then upgrade down the line if I decide I want better performance. Would this combo of cards support large servo motors and offer great motion control? I included a photo below of the rails turns out I actually have enough to make a 50 foot long cnc. I don't think I will ever need to cut 10 sheets In one go but i was thinking of making 25 foot a water table and keep the other 25 foot to plasma cut beams and maybe a large rotory axis. May aswell set it up am I right? 

Hey, does anyone know if the number of repeats remaining is a readable parameter?

Thanks for the answer. In the meantime, I got a EL6731 Profibus device, since my servostar devices do have an extra Profibus interface. After long tinkering, I got at least the velocity mode working with that. I think I will simply use PID control and velocity mode for positioning axis. Next big thing is homing... Can you send me your ds402.comp for the servostar? If anybody is interested, I can post my not yet finished hal-servostar600dp project.
BR Franz

Surely a mesa card can make the frequency that the servo driver can accept.
I read that it can do up to 8mhz
If the driver allows go to quadrature step type
step_type = 2

I want to know how to calculate the maximum step frequency with MESA card.

What are the input datas required..maximum servo period..and??

Done, thank you.