Firmware Request for 7i92 – Plasma CNC Build

 Hello everyone,This is my first post here on the LinuxCNC forum, and also my very first CNC build — so please forgive any mistakes or lack of experience on my part. I'm doing my best to learn as I go.I'm building a plasma CNC machine and using a Mesa 7i92 card. For my setup, I’ll be connecting two 5-axis breakout boards — one on P1 and one on P2. I’m looking for a suitable firmware that would allow me to:

• Use 4 or 5 encoder inputs (for THCAD and potentially other uses)
• Have at least 10 inputs and 5 outputs for general machine control

I’ve checked the Mesa site and the firmware list, but I’m not sure which bitfile would suit this configuration best. If anyone has a firmware file that fits these needs — or could point me in the right direction — I would be very grateful.Thank you so much in advance for your help and patience. I really appreciate the knowledge and support shared in this community.Best regards,

For a 7I92:

7i92_5ABOBx2D.bit

for a 7I92T:

7i92t_5abobx2d.bin

Would be closest If you are using the common "Mach 5 Axis" Sainsmart parallel port BOB

Note that the inputs of the common 5 Axis breakouts are not really suitable for encoder use
as they are quite slow and require 12 V signals.

Yes, I'm using the common 5-axis BOBs from china, one on each port (P1 and P2).
That said, I don’t actually need all 10 StepGen channels. My machine only uses 4 axes, so I’m hoping to free up many of the StepGen-related I/O pins and use them as general-purpose I/Os instead.

Also, since the 7i92 headers are mirrored (P1 and P2), both BOBs give access to the same type of GPIO pins. I’m hoping to take advantage of that symmetry and assign more pins for inputs (e.g., limit switches, ArcOK, ohmic probe, thc UP /down etc.), and just a few for outputs (torch on/off, float switch reset, laser etc.).

Ideally, I'd like a bitfile that allows:

At least 10 inputs and 5 outputs for general machine control

Fewer StepGen channels (maybe 4 or 5 max)

If a bitfile like that exists — or if modifying an existing one is straightforward — I’d really appreciate the guidance.

Thanks again for your help!

Best regards,

A picture or link to the actual breakout board you have would be helpful.

As tommylight noted, the common "5 Axis CNC" breakout has 12 outputs
and 5 inputs and this is fixed by the breakout board hardware.

Hi all,Thanks in advance to everyone who responds!I’m using the following HostMot2 bitfile for my Mesa 7i92:

BoardName : MESA7I92
FPGA Size: 9 KGates
FPGA Pins: 144
Number of IO Ports: 2
Width of one I/O port: 17
Clock Low frequency: 100.0000 MHz
Clock High frequency: 200.0000 MHz
IDROM Type: 3
Instance Stride 0: 4
Instance Stride 1: 64
Register Stride 0: 256
Register Stride 1: 256

Modules in configuration:

Module: DPLL
There are 1 of DPLL in configuration
Version: 0
Registers: 7
BaseAddress: 7000
ClockFrequency: 100.000 MHz
Register Stride: 256 bytes
Instance Stride: 4 bytes

Module: WatchDog
There are 1 of WatchDog in configuration
Version: 0
Registers: 3
BaseAddress: 0C00
ClockFrequency: 100.000 MHz
Register Stride: 256 bytes
Instance Stride: 4 bytes

Module: IOPort
There are 2 of IOPort in configuration
Version: 0
Registers: 5
BaseAddress: 1000
ClockFrequency: 100.000 MHz
Register Stride: 256 bytes
Instance Stride: 4 bytes

Module: QCount
There are 6 of QCount in configuration
Version: 2
Registers: 5
BaseAddress: 3000
ClockFrequency: 100.000 MHz
Register Stride: 256 bytes
Instance Stride: 4 bytes

Module: StepGen
There are 5 of StepGen in configuration
Version: 2
Registers: 10
BaseAddress: 2000
ClockFrequency: 100.000 MHz
Register Stride: 256 bytes
Instance Stride: 4 bytes

Module: PWM
There are 1 of PWM in configuration
Version: 0
Registers: 5
BaseAddress: 4100
ClockFrequency: 200.000 MHz
Register Stride: 256 bytes
Instance Stride: 4 bytes

Module: LED
There are 1 of LED in configuration
Version: 0
Registers: 1
BaseAddress: 0200
ClockFrequency: 100.000 MHz
Register Stride: 256 bytes
Instance Stride: 4 bytes

Configuration pin-out:

IO Connections for P2
Pin#  I/O   Pri. func    Sec. func       Chan      Pin func        Pin Dir

 1      0   IOPort       PWM              0        PWM             (Out)
14      1   IOPort       None           
 2      2   IOPort       StepGen          0        Step/Table1     (Out)
15      3   IOPort       None           
 3      4   IOPort       StepGen          0        Dir/Table2      (Out)
16      5   IOPort       StepGen          4        Step/Table1     (Out)
 4      6   IOPort       StepGen          1        Step/Table1     (Out)
17      7   IOPort       StepGen          4        Dir/Table2      (Out)
 5      8   IOPort       StepGen          1        Dir/Table2      (Out)
 6      9   IOPort       StepGen          2        Step/Table1     (Out)
 7     10   IOPort       StepGen          2        Dir/Table2      (Out)
 8     11   IOPort       StepGen          3        Step/Table1     (Out)
 9     12   IOPort       StepGen          3        Dir/Table2      (Out)
10     13   IOPort       None           
11     14   IOPort       QCount           0        Quad-A          (In)
12     15   IOPort       QCount           0        Quad-B          (In)
13     16   IOPort       QCount           0        Quad-IDX        (In)

IO Connections for P1
Pin#  I/O   Pri. func    Sec. func       Chan      Pin func        Pin Dir

 1     17   IOPort       QCount           1        Quad-A          (In)
14     18   IOPort       QCount           1        Quad-B          (In)
 2     19   IOPort       QCount           1        Quad-IDX        (In)
15     20   IOPort       QCount           2        Quad-A          (In)
 3     21   IOPort       QCount           2        Quad-B          (In)
16     22   IOPort       QCount           2        Quad-IDX        (In)
 4     23   IOPort       QCount           3        Quad-A          (In)
17     24   IOPort       QCount           3        Quad-B          (In)
 5     25   IOPort       QCount           3        Quad-IDX        (In)
 6     26   IOPort       QCount           4        Quad-A          (In)
 7     27   IOPort       QCount           4        Quad-B          (In)
 8     28   IOPort       QCount           4        Quad-IDX        (In)
 9     29   IOPort       QCount           5        Quad-A          (In)
10     30   IOPort       QCount           5        Quad-B          (In)
11     31   IOPort       QCount           5        Quad-IDX        (In)
12     32   IOPort       None           
13     33   IOPort       None         

   

1. I only need 4 axes (X, Y1, Y2, Z). Can I use the last StepGen for torch on and laser pointer outputs?
2. I do not need encoders. Can I use the QCount pins as general-purpose inputs?
3. Can I use the pins labeled “None” or “unassigned” in the bitfile as inputs or outputs, depending on their pin direction?For example, pins 10 and 15 as inputs, and pin 14 as output?
4. Are pins 13 and 15 on P2 free to use as I/O?
5. My breakout board has 5 inputs labeled P10, P11, P12, P13, and P15. Can I use all of them as inputs

thanks again to everyone who helps!Best regards,
 

Hello again everyone,First, I apologize for the late reply — I’ve been working on revising my plan and wiring, and it took longer than expected.I’ve updated my wiring/architecture plan (see attached diagram), and here’s where I’m at:

• Mesa 7i92 over Ethernet
• Two 5-axis breakout boards (5ABOB ×2)
• DM556 drivers for NEMA34 motors (3.5 Nm, 3 A/phase)
• THC Proma 150 for torche height control (Arc OK, Up, Down signals)
• Relays for torch, laser, pump, etc.
• E-stop, limits, probe via optoisolators
• Power supplies: 5 V/8 A, 24 V/3 A, 36 V/12 A

On one BOB (P1) I plan to handle signals like Arc OK, Up, Down, E-stop, relays; on the other BOB (P2) I plan to handle limits, probe, and driver step/dir lines.Questions

1. With that setup (7i92 + 2 × 5ABOB), is the wiring architecture I’m proposing feasible?
2. I was thinking of starting with the G540 HAL/INI config in pncconf as a base, then editing it . Is that a sensible approach, or is there a better workflow to generate a clean HAL/INI for this sort of layout?

Thanks again to PCW, tommylight,  Your help is very valuable. Any further feedback or corrections before I begin wiring would be hugely appreciated.