Bitfile or help – Mesa 6i25 + 7i74 (BiSS-C) + 8i20 + 7i70/7i87

Hello,I am new to LinuxCNC and Mesa hardware and I am working on a relatively large project. Before going further, I would like to ask for advice to make sure I am approaching the configuration correctly.
I am on a linux 4.19.0.21 -rt - amd64 smp preempt rt debian.
My hardware configuration: Mesa 6i25 (PCIe) Connected via P3 (external connector) to a Mesa 7i74. It is intended to interface a signal BiSS-C from a RAIK060 BiSS-C rotary encoder used for motor position feedback. A mesa 8i20 Powerdrive for the motor associated with the BiSS-C encoder. A mesa 7i70 and a mesa 7i87 are used for another part of the project: Temperature sensor, Pressure sensor and one servo motor.
II am planning to build a custom wiring setup using a RJ45 cable to carry the BiSS-C signals. To connect this cable to the first RJ45 port on the 7i74.
Current status: I have tried modifying an existing VHD file as a starting point, however I am not confident that the overall architecture is correct or my intended usage. What I am looking for is general guidance on the recommended architecture for this combination of cards ( a bitfile would also be perfect ) any advice on a suitable firmware for the 6i25 + 7i74 (BiSS-C), any pitfalls to avoid or best practices for a setup of this size. I understand this is a complex setup for a beginner, but I would need help and be thankful for your time and help.

Bitfile (and changed source)  for 5i25/6i25 with 7I74 and 4 sserial channels and 4 BISS channels:

 

Pretty sure Tommylight has some example files using SSI feedback (which is very similar at the HAL level)

Thank you for your help, I'll check that right away.

PCW wrote:

Pretty sure Tommylight has some example files using SSI feedback (which is very similar at the HAL level)

Yes of course, they are attached in the Elumatec SBZ130/01 retrofit page, not sure if i updated to the latest version so you might have to go through quite a long topic to check, although might not need the latest as the encoders were the first thing working, after the initial wiring. The latest should also have the toolchanger with grayscale feedback.

Hello again, I was sick for a week, so I didn't make much progress.
My boss want a change in our configuration, he want to replace the 7i70 by a 7i76 connected on the port p2 from the 5i25. I wanted to know if it need a change in the bitfile or if i can use something existent like the file "5i25_7i76_7i74biss3d" that you (PCW) provided here: forum.linuxcnc.org/24-hal-components/551...-biss-encoder#320220 ?
I tried to read and to understand what was in the vhd but i am not good enough for making it myself...

In order to experiment i already tried to used this existing bit file "5i25_7i76_7i74biss3d" in addition to an existing hal (the two are not from the same project) but i have an issue. When i tried to modify my hal in order to use the two serial port like this:
loadrt hm2_pci config="num_encoders=0 num_pwmgens=1 num_stepgens=5 sserial_port_0=0x00xxxx sserial_port_1=0XXX"
with p3 => 7i74 = 0 => bissc 3 => 7i87
et p2 => 7i76.
In my understanding my hm2_pci config should be correct and be followed by : hm2_5i25.0.7i76.1.0.input,  hm2_5i25.0.7i74.0.0.something and hm2_5i25.0.7i74.0.3.otherThing? But i get an error: hm2/hm2_5i25.0: num_serials references 2 instances, but only 1 are available, not loading driver ...etc
I dont know if the issue came from the bit file or from the hal.

In the meantime, I will continue reading the hal manual.
Once again thank you for your help!

The error is a hal error, there is only one sserial port in that configuration.

BISS is not related to sserial and is set up differently in the hal file.

The hostmot2 man page describes the driver command line for BISS devices.
Unlike sserial devices, BISS devices are not "discoverable" so need to be setup
with device specific data in the driver command line.

man hostmot2

and scroll down to the BISS section.