Mesa 5i25 + 2x7i77 +2x7i84

Hello Community,

for a bigger milling center, I want to use one 5i25 with two 7i77 one on p3 and the other one on P2 oft the 5i25.
Then two 7i84 connected to the RS 422 ports of each 7i77cards.

My problem is, that one of the 7i84 will not be detected,
I can't find the card connected to the 7i77 on port 2.

Do I need a special config string or something ?

Thank you very much !

For this to work you need:

1. 5V to both 7I77s
2. Field power to both 7I84's
3. The correct firmware in the 5I25 (7I77x2)
4. A config string that enables all 6 channels
for example sserial_port_0=000000xxxx or sserial_port_0=302302xxxx

Hello; thanks for the fast answer!

I have connected 5V to both cards an jumpered them exact.
Field power is there
I used the PNC conf to set it up with 7i77x2
And I enabled the channels right

If I plug the undetected 7i84 in the other 7i77 it can be found.

Do I have the wrong firmware on the 5i25 ?
How can I change this ?

what is your hm2_pci config string? can you post it here?

you can read the firmware pinout with mesaflash and verify that its correct

to read your firmwares pinout you run mesaflash

sudo mesaflash --device 5i25 --readhmid

or to save the output into a file

sudo mesaflash --device 5i25 --readhmid > config.txt

you should be able to post config.txt here

to reprogram the 5i25 you use mesaflash with the -- write option:

sudo mesaflash --device 5i25 -- write 5i25_7i77x2.bit

You may have to power cycle the PC to get the new firmware to load
but if the old firmware was new enough you can use the reload option

sudo mesaflash --device 5i25 --reload

Sorry for the late answer, I was very busy at this time.

here is the config string:
The next thing we are going to do is checking if we have to flash the 5i25.
I will post it here.

Greets Rene

Hello, here is the output of some terminal commands, I tested with mesaflash.

Not sure whats going on but perhaps a bad cable (serial or parallel) or bad 7I77

(assuming you dont get a green blinky light on the second 7I84 if you start linuxcnc and you have
a sserial_port_0=000000 token in the hm2_pci config line)

Hello,
now we did the following :

-swapped the two 7i77 => same error, 7i84 is missing
-swapped the two 7i84 => same error, 7i84 is missing
-changed out the 5i25 with another one => same error, 7i84 is missing

Then we tried different cables (all of them are tested!)
-Cable 1 => same error, 7i84 is missing
-Cable 2 => another error 7i84 is there and 7i77 is missing
-Cable 3 => all cards are here but if we start the config we get error 13 connection timed out to serial port 3 but green light is still blinking

I don't know what's going on, we checked every cable and all of them are the same and all of them are good and the cable that works best is the longest cable!
EMV can't be a problem either we used the same hardware on the first 7i77 and 7i84 and we never get a problem with them.

I hope someone from Mesa can help us.


Greets and thank you all !

Are you powering the 7I77s from the FPGA card?
One possibility is that you have too much 5V drop
So need to power the 7I77s from an external 5V supply
(this requires moving jumpers on both the 7I77 and 5I25 cards)