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7i84U is probably next week and the 7I96S about 3 weeks out

Thanks — that’s a good point. I did see that the 7i96 (non-S) is currently in stock and that it would work for THCAD-2 and encoder input.

That said, for this machine I’m trying to stay fully within the Mesa ecosystem with maximum flexibility and isolation, and to keep things future-proof in a noisy industrial environment. Even if I don’t strictly need 0–10V today, the added analog output and larger FPGA on the 7i96S make it more attractive for my long-term use.

If 7i96S restock is expected in the near term, I’m inclined to wait and standardize on that rather than mixing generations.

If you do not need the 0-10V analog output for VFD, there are in stock Mesa 7i96 without the S, they do have an encoder input:
store.mesanet.com/index.php?route=produc...oduct&product_id=311

Thanks Peter — one additional note: I also see that 7i96S and 7I84U are currently showing as out of stock on the Mesa store.

My preference is to stay fully within the Mesa ecosystem (rather than using generic BOBs), so if there are any expected restock timelines for 7i96S and 7I84U, or recommended current-production alternatives that keep a similar architecture, that would be very helpful for planning.

I can wait a bit if needed, but I’d like to avoid purchasing from Europe if these boards are expected to be restocked or revised in the near term.

Thanks Peter — that’s very helpful.

That aligns well with my use case. Since the IL-1000 is only ~10 Hz bandwidth and Y motion is intentionally slow, trading loop bandwidth for higher effective resolution via low-pass filtering sounds ideal for stable stand-off control.

Given that, THCAD-2 looks like the right solution for the current phase, especially with it coming back in stock shortly.

For any future higher-speed sensor upgrades, I’ll revisit true ADC options like the 7i87 if needed — but for now THCAD-2 + filtering seems well matched to the application.

In addition, I will need extra isolated digital I/O for valves, interlocks, and machine signals. I was looking at the 7I84U isolated remote field I/O card (sourcing/sinking outputs), but it currently shows as out of stock. My preference is to stay within the Mesa ecosystem rather than using generic BOBs, to keep things robust and well-supported in an electrically noisy environment.

If you have any guidance on availability of the 7I84U, or alternative Mesa smart-serial I/O options that integrate well with 7i96S for isolated field I/O, I’d really appreciate your recommendation.

Thanks again for the detailed clarification.

The THCAD2 should be back in stock in the US by the end of the week.

Our other analog input card (the 7I87 6 channel +- 10V card) will still be about 4 weeks
but you don't need 6 channels...

For the THCAD2, the update rate is the servo thread rate (giving a loop bandwidth
of about 300 Hz at ~10 bit resolution) You can get better resolution by low pass
filtering (in hal) the frequency signal at the expense of loop bandwidth of course.

 If your height sensor only has 10 Hz bandwidth, you could easily increase the resolution
(to 12 bits or so) by this filtering since it will not affect system loop bandwidth significantly.

Thanks for the feedback — appreciated.

To clarify, my primary focus right now is using the Keyence IL-1000 for slow stand-off correction. Based on the discussion, I agree that THCAD-2 into a 7i96S encoder input should be sufficient in terms of raw speed and isolation for this use case.

My main concern is less about servo-thread rate and more about effective sensor update rate, frequency-to-velocity measurement noise, and required filtering/deadband for stable Y correction in a noisy industrial environment.

I’ve contacted Mesa support regarding isolated analog input options to complement a 7i96S-based system, but haven’t received a response yet. At the moment, many Mesa ADC-related boards appear to be out of stock in the US, and I’m considering purchasing from Europe. However, I’m a bit concerned about committing to hardware if Mesa is planning to release newer or replacement analog/ADC solutions in the near future.

If you (or others) have practical recommendations for current Mesa ADC hardware that works well with 7i96S, or insight into Mesa’s roadmap for analog input, I’d really appreciate hearing them.

LK-G3000 is only a possible future upgrade — the current design focus is on making IL-1000 work robustly and predictably.

All that seems easy enough and Mesa combo should be more than enough fast for everything you mentioned.
1. Yes
2. No, unless you need something extremely fast, 1000Hz is normal servo rate, and even that can be pushed further
3. should all be doable easily, and 10Hz is very slow
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In general, plasma is the biggest offender regarding EMI noise, so you should be perfectly fine, granted the wiring and grounding and shielding is done correctly.
Regarding XYZ, it will be much easier to do a normal CNC machine setup, everything else can be set in gcode or some automated VCP panel to make use much easier and requires one time setups.
-
I have been tasked with such painting automation about 15 years ago but the financing failed, still had some time to do some thinking about implementation, hence i might be a bit fuzzy on details.
Go for it, that would be my personal advice.

Hi all,I’m building a large vertical machine for laser cleaning and automated spray painting of heavy equipment (excavators, cranes, large fabricated parts and enclosures).Motion concept is a raster-based process:

• Z axis performs the working stroke (up/down) where laser cleaning or spray painting is applied
• Y axis is used only for slow stand-off distance control (surface following)
• X axis is used only between strokes for step-over / overlap indexing, then the next Z stroke starts
  
  For painting, we use automatic air spray guns (not airless / not AAA), since painting is done in a general workshop area without a dedicated spray booth. Typical overlap is around 60–70% between strokes.Current and planned hardware:
  • Mesa 7i96S (Ethernet, step/dir drives)
  • THCAD-2 for isolated analog-to-frequency input
  • Keyence distance sensor (starting with IL-1000, possibly upgrading to LK-G3000 series later)
  • Current: manual air spray gun 
  • Planned: automatic air spray gun 
  • Typical speeds:
    • Z working stroke: ~15–40 mm/s
    • X step-over between strokes: index only (no distance control)
    • Y axis: slow stand-off correction only
      
      Environment is electrically noisy (industrial equipment, welding, laser), so isolation is important.My questions:
      1. For this type of slow stand-off control on Y, is using THCAD-2 into the 7i96S encoder input a reasonable approach (non-plasma use)?
      2. If I upgrade to a faster sensor (LK-G3000), does THCAD-2 become a bottleneck for meaningful improvement?
      3. If I want proper fast isolated analog input, which Mesa hardware would you recommend to add ADC capability to a 7i96S-based system?
      4. Any practical tips for filtering, deadband, and loop rates for a ~10 Hz sensor like the IL-1000 in this application?
         
         Thanks in advance for any advice.

So I built a CNC plasma cutter out of garbage.... and since I built it out of garbage, I used a very old computer to run it.  It's a 32bit computer, so I'm stuck running Linuxcnc 2.8.  I got a base configuration working and running fairly well, but because it's made out of garbage, it really needs torch height control.  I got a THCAD and got everything wired up to my Mesa 7i96s, and ran the PlasmaC configurator.  The buttons on the bottom of the screen work, I can test the ohmic probe, and the probe cycle seems to work, but I can't get any of the GladeVCP components to load.  The tabs are there, but they're blank, and if I try to configure it with a Run panel instead of the run tab, it doesn't show up.  The other issue I have is I can't load a G-code file, it seems to get stuck "Filtering."  On top of that, I'm now having latency issues I wasn't having before.  I've been staring at and trying to troubleshoot my configurations for way too long and I can't find anything obviously wrong, so I suspect this 20+ year old Dell just isn't up to the task.  Part of the "art" of this machine was that it's made of junk, so if I can keep using this computer, I'd like to... but I'd also like the machine to work properly, so I figured I'd at least upload my configs for someone more knowledgeable to look at before I buy something more modern.

I wrote this up in chat gpt pretty quickly I think it just about covers all of the bases here of the project.

CNC Plasma Table – Electrical & Wiring Requirements

Project: Remote design of electrical system + wiring documentation for LinuxCNC plasma table
Client: TCB Metal Works

1. Project Overview

You will remotely design the complete electrical and control system for a custom CNC plasma cutting table powered by LinuxCNC.

You will create:

Complete wiring diagram set (schematic + physical routing)

Full Bill of Materials (BOM) with real part numbers

Wire gauge, shielding, grounding, and EMI mitigation plan

Bulkhead connector list + panel layout

Mesa board selection + full LinuxCNC I/O map

Integration notes for all components

Testing & commissioning checklist

This is a 100% remote engineering job — no physical inspection of hardware is required.

2. Available Power Sources

Near the machine:

220 VAC available

460 VAC available

No dedicated 110/120 VAC, which must be generated using a control transformer if needed

Engineer must design the incoming power strategy and transformer selection.

3. Motion Hardware
3.1 X & Y Axis – AC Servos (Provided)

3× A6 Series 1000W RS485 AC Servo Motor Kits

3000 rpm

3.18 Nm

17-bit absolute encoder

IP67 motors

Axis layout:

Y axis: 2 servos (dual-drive gantry)

X axis: 1 servo

Notes:

Motor-to-drive cables are already supplied by the manufacturer.

You do not need to design or evaluate those cables.

Engineer must:

Design AC mains wiring to each servo drive

Design control, enable, alarm, and ESTOP signal wiring between drives and Mesa

Include needed fuses, breakers, filters, and terminals

Provide cabinet layout and routing plan

Include proper grounding and shielding recommendations

3.2 Z Axis – Stepper Motor (Needs Driver + Cable)

PV267-D2.8AA stepper motor — Oriental Motor

Stepper driver not provided

Stepper motor cable not provided

Engineer must:

Select a compatible stepper driver suitable for PV267-D2.8AA + LinuxCNC step/dir

Define driver voltage supply requirements

Design:

Step/Dir wiring from Mesa

Motor wiring from driver to Z motor

Required cable shielding, gauge, and insulation

Connector type and strain relief

4. Control Electronics (Mesa + Power)

Engineer must select Mesa hardware capable of supporting:

3× servo axes

1× stepper axis

THC-AD

Ohmic sensing

All limit/floating switches

Plasma start / Arc OK

E-stop & safety I/O

Deliverables:

Recommended Mesa board combination (e.g., 7i76E, 7i96S, 7i85, THCAD, etc.)

Justification for chosen hardware

Complete LinuxCNC I/O mapping

Required DC power supplies (24V / 5V / others)

Proper AC distribution, fuses, breakers, and protection devices

5. Torch Height & Ohmic Sensing
5.1 THC-AD Integration

Engineer must design:

Raw arc voltage wiring from Hypertherm HT2000 to THC-AD

THC-AD signal wiring to Mesa

Required shielding and filtering

Scaling notes for LinuxCNC

5.2 Ohmic Sensing (Planned)

Engineer must:

Recommend a compatible ohmic board

Provide wiring diagram for torch → ohmic board → Mesa

Specify cable type and shielding

Document signal polarity & behavior

6. Hypertherm HT2000 Integration

Engineer must design wiring for:

Required signals

Torch start / trigger

Arc OK

Raw arc voltage (+/–) into THC-AD

Required protection

Isolation (if needed)

Surge suppression

Filtering

EMI protection

Routing rules

Arc voltage wiring must be kept separate from low-voltage control wiring

7. Limit Switches & Floating Head
X Axis

2 limit switches:

X-min

X-max

Y Axis (Dual Gantry Drive)

2 limit switches:

Y-min

Y-max

Engineer must propose a reliable gantry squaring / homing method for the two Y motors.

Z Axis

2 end-of-travel limit switches:

Z-min

Z-max

1 floating-head switch (touch-off)

Engineer must:

Select appropriate switch type (mechanical or prox)

Provide wiring diagrams to Mesa

Specify wire gauge, shielding, and cable routing

Provide LinuxCNC input mapping

Include any debouncing/filtering requirements

8. Wiring, Shielding, & EMI

Engineer must specify:

Wire gauges for:

AC mains

Servo drive feeds

Stepper driver feeds

Stepper motor wiring

Limit/floating/ohmic wires

Plasma signals

DC supply lines

Shielding requirements for:

Step/dir

Limits/floating/ohmic

Arc voltage

THC-AD lines

EMI considerations

Cable separation

Ferrite locations

Filtering recommendations

9. Grounding & Bonding

The engineer must design the grounding/bonding approach.

Important physical detail:

The water table, gantry, and control cabinet are three separate physical assemblies.

The engineer must account for this when designing:

Grounding/bonding layout

EMC/EMI mitigation

Plasma return path considerations

Ohmic sensing grounding

No grounding method (star, bus, single-point, etc.) is mandated — the engineer chooses the correct approach.

10. Control Cabinet & Bulkheads

Engineer must design:

Cabinet Layout

AC distribution, transformers, PSUs

Mesa boards

Servo drives

Stepper driver

Fuses, breakers, contactors

DIN rail layout

Ventilation/fans

Bulkhead Connectors

Used wherever practical for:

Servo cables (using glands or pass-throughs)

Z stepper cable

Limit/floating switches

Ohmic sensing

Plasma start / Arc OK

E-stop / operator controls

Ethernet access

Engineer must specify:

Connector type

Pinout

Panel cutout style

Labeling

11. Documentation Package

Engineer must deliver:

11.1 Wiring Diagram Set

Full schematic

Cabinet wiring

Field wiring

Power distribution

Grounding/bonding

Bulkhead connector pinouts

11.2 BOM

Complete list of:

Mesa hardware

Stepper driver

Transformers / PSUs

Switches

Connectors

Wire/cable

Protection devices

Cabinet hardware

11.3 I/O Map

All LinuxCNC inputs/outputs

Axis definitions

THC/ohmic mappings

E-stop & safety signals

11.4 Commissioning Checklist

Power-up verification

Servo enable/jog

Stepper test

Homing / gantry squaring

Z floating-head test

Plasma start / Arc OK

THC test

Ohmic test

EMI/noise checks

There is not much point upgrading from THCAD5 or THCAD10 to THCAD to THCAD2 as it is functionally identical except you can select 0-5v or 0-10 volt scales.

I personally think 150v is a bit low given cutting volts can be up around 130-140 volts. I would set to 180 to 200 volts.

Unser Plasmaschneider Hevy-Metal hat diese Jahr gute Dienste und schöne Ergebnisse geliefert....
Des halb haben wir uns entschlossen das THC nach zurüsten....
Erste Frage da wir damals die falsche Firmware genommen ( 7I96S_7I74 )haben gibt es ein Chaos wenn wir auf 7I96S-dpl gehen ?
Frage zum THCAD2 High isolation A-D:
10 V Full Scale
Wiederstände sind ok
Da der Plasmaschneider etwa 103 V beim Schneiden abgiebt was sich mit den Typenschild decktist die frage kann ich auf 150 V gehen für die Wiederstands berechnung oder sollte man auf 200 V gehen ?
Output Frequency ??Mode F/32 oder weiche für die 7I96S ?
Die Eingänge auf der 7I96S Endcoder-Stecker immer die beiden unteren wie in Beitrag 
MESA THCAD-2 - couple quick questions ?

Das war es fürs erste.

---

Our Heavy-Metal plasma cutter has served us well this year and delivered great results.... Therefore, we've decided to upgrade to the THC....
First question: Since we used the wrong firmware (7I96S_7I74) back then, will there be any problems if we switch to 7I96S-dpl?
Question regarding the THCAD2 High Isolation A-D
10V Full Scale
Resistors are OK Since the plasma cutter outputs about 103V during cutting, which matches the nameplate, the question is: Can I use 150V for the resistor calculation, or should I use 200V?
Output Frequency? Mode F/32 in the THCad 2 for the 7I96S?
The inputs on the 7I96S encoder connector are always the two lower ones, as in the post "MESA THCAD-2 - couple quick questions" ?
That's all for now.

king regard e Juergen

Hi everyone,I’m finishing up my CNC plasma build using a Mesa 7i96s, Spartus ProCut 45PCF, and a THCAD-5 (not yet connected).My issue:
The torch on output (OUT0) from the Mesa won’t trigger the plasma directly.
If I short pin 3 & 4 on the Spartus CNC port manually, the torch fires instantly.
When I run the signal through a relay, it also works fine.
But when I connect the Spartus directly to OUT0+ and OUT0-, (or OUT5) nothing happens — even though the Mesa output LED lights up and I can measure switching.The Arc OK behaves similarly — it only works through a relay. But when i have torch pulse on it stays active. And when cutting a circle is just flashes real quick and torch dies. 
The output LEDs on the Mesa board are about half as bright as the input LEDs.All 0 V lines in my control cabinet go to a common terminal, which is also tied to PE (earth) and the machine frame.
I have 24 V on IN COMMON, and everything else seems correct.Has anyone successfully triggered a Spartus ProCut 45PCF directly from a Mesa 7i96s output (without a relay)?
If so, could you share how you wired OUT0+ / OUT0- relative to the plasma CNC port pins (3–4)?I’ve looked through other wiring diagrams and posts, but haven’t found a clear answer yet.
Any suggestions or example diagrams would be very much appreciated. I will try and make a diagram of mine so you guys can have a look )Thanks!

Long story short, a lot of things were changed before I replaced the the 7i97t. Since then, I have have been cutting with zero issues. The thcad for arc volts is reading accurately while cutting. The thcad for ohmic is not hooked up. I can't get it to work, but maybe that's a good thing because it sounds like it's a bad idea with hf start.

The longer story is that this machine didn't have a home. So while its new home was being built, I set it up temporarily in my shop, so I could attempt to retrofit it with linuxcnc. When I fired up the torch for the first time, it damaged the 7i97t. This was with both ohmic and arc volts hooked up, so its anybodys guess what caused it. I added some grounds and an emi filter and few other things then replaced the 7i97t. Then I got it working great with a non hf plasma(except I didn't hook up ohmic).
Then after it was moved into its new home, we added several ground rods and hooked it up to the hf start plasma the way you had just advised. It's been cutting great. 

I know I ask a lot stupid questions but I do appreciate the help.