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Hi Todd,

Thanks for your response — I’ll definitely give that a try, as it feels like my last resort with this current setup.

I've already disabled everything I possibly could in the BIOS. The only things I haven't touched yet are the memory timings and voltages. If this doesn’t work either, I’m honestly not sure what else is left to tweak.

I'm also considering switching to a Mesa card, possibly the 7i76EU, but I have zero experience with Mesa hardware. I’ll need to figure out whether it will work with my three DM542A stepper drivers, and also with my VFD, which is currently controlled over USB using: `loadusr -Wn vfd hy_vfd -n vfd -d /dev/ttyUSB0 -p none -r 9600`

Things i disabled next to the obvious, like settings for fixed clock speeds (fclock 1066, bclock 1000) disabling power management and disabling hardware that is not being used (BT, Wireless, serial, audio, fancontrol (disabled fixed on 100%)):

BIOS Settings (set to Disabled):

SMT / Hyperthreading
→ Disables logical cores to reduce cache sharing and latency spikes

C1E, C6, and other C-States
→ Prevents the CPU from entering sleep states, ensuring consistent timing

Streaming Stores Control
→ Avoids aggressive memory write optimizations that can disrupt real-time behavior

DRAM Scrub Time
→ Turns off background memory error checking to avoid unexpected memory bus usage

GMI Encryption Control
→ Disables inter-chiplet encryption on Infinity Fabric to reduce overhead and latency

XGMI TXEQ Mode
→ Prevents signal equalization tuning that could introduce instability or variability

DRAM Map Intervention
→ Disables memory remapping logic that can introduce unpredictable latency

DF Sync Flood Propagation
→ Prevents error broadcasts across chiplets, reducing the chance of system-wide stalls

Good day,
Adding a voice here as I think I saw another user having this issue: RPI5 with a 7i96, and after some time I get a solid red INIT light on the mesa card, and obviously at that point have to reset the card to continue. I cant make heads or tails of this just yet, but it might be related to idle. It may be specific to the 7i96 given the other poster also commented on that. I have 7i76EU on its way so will be able to test this and post back whether I experience anything similar. Currently the Mesa is on a 5v3A wall plug, and the RPI5 uses a somewhat official USBC RPI wall plug.

Working like a charm.
Thank you very much Peter!

P.S.
Damn self-made DB25 cables. Firmware initially didn't make any difference. Apparently cables on P1 and P2 were backward. Reversed both DB25 connectors and now I see both 7I76 and 7I89 and encoders are working. These Mesa cards seem to be very robust, even all wrong signals on all the wrong pins didn't make them go dead.

7I76EU firmware with 7I76 on P1 and 7I89 on P2

 

Each connector is independent, though module channels may differ between firmwares
Note on the 7I89, you may need to turn on Encoder power (depending on jumpering) and it
also requires  both cable  _and_ external 5V supply to P1.

PCW wrote:

Wrong firmware, 7i76eu_7i76x1_7i88_7i89d.bin is for a 7I76EU +7I88 (P1) + 7I89 (P2)

I'll take a look at making a config for a 7I76 (P1) and 7I89 (P2), but probably tommorow...
 

Would it be 7I76U (with sink/source I/O option and spindle/encoder interface) on P1 and 7I89 on P2?
Also, 7i76eu_7i76x1_7i88_7i89d.bin has 7I89 on P2. Should 7I89 on P2 work even if 7I76 on P1 doesn't? Or P1 and P2 handling is interdependent?

Wrong firmware, 7i76eu_7i76x1_7i88_7i89d.bin is for a 7I76EU +7I88 (P1) + 7I89 (P2)

I'll take a look at making a config for a 7I76 (P1) and 7I89 (P2), but probably tommorow...
 

That may be, but I have 7I76U and its manual says (www.mesanet.com/pdf/parallel/7i76uman.pdf page 5) that sserial should be on DB25 pins 7-10 (two of them in fact), while 7i76eu_7i76x1_7i88_7i89d.pin file has just one sserial on pins 11-13 and no spindle encoder. It instead has 2 additional stepgens which my 7I76U doesn't have.

Might want to wait for confirmation from PCW, but to me it seems all good, and yes sserial's must be there as 7i76 has a sserial port and uses another sserial channel for IO.

Here it is. 
As I see it, pinout for P1 connector (where 7I76U is connected) is wrong for pins 7-13 (Sserial and spindle encoder)
 

koch777 wrote:

That one has all the right pinouts, but seem to be for older generation of 7I76 (Spartan FPGA?), not sure it will work for my 7I76EU (Efinix FPGA)

It does not work and might brick the card, well i am sure it will brick it, but being Mesa there might be ways to save it, so do not flash that.
Post the result of mesaflash readhmid here se we can have a look.

Hello everyone,

So, I have this configuration:

• Main board is Mesa 7I76EU
• 7I76U connected to main board expansion header P1
• 7I89 connected to main board expansion header P2

Main board's +5V is connected to P5; +24V field power - to TB1.
Actually, never mind, main 7I76EU is not a problem, it works, everything's detected, steppers are moving, spindle/spindle encoder are working, MPG is working.

Now, expansion 7I76U (on P1 header) is indicating communication failure (red led in the middle of te board). It doesn't show up in halconfig (should it?). Field power is there, cable power from main board is there.

For 7I89 I see all 8 encoders, but encoder inputs do not react to signals from encoders. None of the encoder input-a/input-b/rawcounts change despite the fact that physical signals from encoders are. Encoders are TTL and so 7I89 is jumpered accordingly.
+5V power to 7I89 is connected to its P1 and cable power from 7I76EU is activated as well (per 7I89 manual). Encoders are powered and working just fine (checked with oscilloscope).

Firmware I load is from mesa website: 7i76eu_7i76x1_7i88_7i89d.bin
It is somewhat strange as its 7i76eu_7i76x1_7i88_7i89d.pin file has stepgens 10/11 where 7I76U (P1) should have Sserial and it also has Sserial where should be MuxedQCount (spindle encoder). Basically I/O for DB25 pins 7-13 is all wrong for 7I76U.
Probably that's why my 7I76 doesn't work.

I'm afraid to load firmware from post www.forum.linuxcnc.org/27-driver-boards/...7i89-firmware#240149
That one has all the right pinouts, but seem to be for older generation of 7I76 (Spartan FPGA?), not sure it will work for my 7I76EU (Efinix FPGA)
It also has clock high frequency set at 200MHz, while 7i76eu_7i76x1_7i88_7i89d.pin shows 160MHz.

How can I get out of this predicaments?
Can anybody help?

For basic step/dir servos, a 7I76EU should do (by itself)

The 7I76EU has:

5 axis of step/dir outputs
32 digital inputs (5 to 24V)
16 digital outputs (5 to 24V)
Isolated analog 0..10V output for VFD spindle speed control
encoder input for spindle synchronized motion
2 parallel expansion ports (for additional step/dir or encoder channels)
1 serial expansion port (for more digital I/O

 

i asked ChatGPT about the boards, and it said I should use the 7i76e for axis control, the 7i85 for secondary axes, and the 7i89 for encoders.
Is this configuration correct?I also want to add some information about the servo motors I'm planning to buy.
I don't fully understand all the technical details, but if there is anything wrong or incompatible, I would really appreciate it if you could let me know.
Thank you!  

drive.google.com/file/d/1As0Eivp9ck6G0jz.../view?usp=drive_link
 

PCW wrote:

Yes, a fairly ancient version of mesaflash (3.4.9)  is included with the
LinuxCNC 2.9.4 ISO, this is supposedly fixed for later releases.

I don't think mesaflash is included in V 2.9.4 in our ISOs because it is seperate to Linuxcnc and has its own Deb file.
If that is the case, 2.9.4 will just get the very early version in the Bookworm repo.
Perhaps Our Debian build system should be modified to  make mesaflash so it gets stored in our repos

Yes, in most cases, mesaflash is not needed as the installed firmware is sufficient.