Onkelmat wrote:

Pnconfig wizard doesn´t work for it. (....)  that config with linuxcnc it doesn´t even find the card and exits with an error that the network isn´t reachable. 
 

I tried pncconf once and only wasted time... But always when I found config similar to my needs I can change those as I want. 
This is Windows Philosophies contra Linux Philosophies...
In Linux you can do anything in terminal. You must know some magic words, but always you can find solution.
In Windows you use mouse and click on icons. You can nothing when no icons for click...
BTW. Read carefully error messages. Not always, but mostly they gives solution.

i believe all amps start with 0x92, then 0x7a, then you can continuously poll it with 0xa2. the answer to 0xa2 is straight-forward:
int16_t abs1 = rxbuf[5] + (rxbuf[6]<<;
uint32_t cyc1 = rxbuf[2] + (rxbuf[3]<< + (rxbuf[4]<<16);
abs1 is full rotations counter, cyc if within-rotation position. afair, it is left-justified to 20 bits, so with your OBA18 encoder 2 LSBs may be always 0.
the last byte of a frame is a xor checksum, not a CRC

Good! I need it too, I just ordered one from Europe to replace my DC servos with Sanyo RS2 ac

There is also:
spindle.N.inhibit - (bit, in) When this bit is TRUE, the spindle speed is set to 0.

Ok if you are using Master branch, I just pushed work to return to the original mode for most things I could find, probing, MDI convince buttons, etc.

Please check it out and let me know what you think or what I missed.

Chris

Here is a sample 7I97/7I97T hal/ini configuration:

 

There's also an experimental pncconf version that supports the 7I97 you might try:

forum.linuxcnc.org/plasmac/55286-servo-d...ofit?start=10#331289

 

Hi everyone,I am a Master's student currently working on my thesis, which involves designing a custom, low-voltage FOC Servo Driver to control a Mitsubishi MR-J3 motor (equipped with the 18-bit absolute encoder, model J-A22/J-A24).My goal is to achieve full closed-loop control (current, speed, and position) using a custom control board. I am determined to implement the encoder decoder myself rather than using commercial converter modules, as the academic board requires a deep dive into the firmware.What I have done so far:

1. Hardware Interface: I designed a custom PCB utilizing a high-speed RS-485 transceiver (MAX3485) connected to the USART peripheral of an STM32G4 MCU. The differential lines (MR/MRR) are properly terminated with a 120-ohm resistor.
2. Signal Capture: I have configured the MCU's USART to run at 2.5 Mbps (8N1), utilizing DMA to handle the high-speed RX buffer without blocking the CPU.
3. Prior Research: I have deeply analyzed open-source projects like STMBL and various threads on the LinuxCNC forum regarding the "Mit-A/Mit-B" protocols.

The Roadblock: While I can physically capture the serial stream, I am currently struggling with the deterministic behavior of the protocol:

• The Request Command: I am trying to identify the exact initialization/request byte sequence that the Master needs to send to "wake up" or poll the encoder continuously. I tried sending
  Code:

  0x02
  and
  Code:

  0x1A
  based on some older J2S documentation, but the encoder response is inconsistent.
• Frame Parsing & CRC: Once the encoder responds, I receive an 7-to-9 byte packet. I am trying to figure out how the 18-bit position data is packed across these bytes (Little-Endian shifting vs. Scrambled bits), and what specific CRC-8 polynomial (and initial value) is used to validate the frame.

I am not looking for ready-made code or copy-paste libraries. I want to understand the underlying data structure and state machine of this specific encoder protocol so I can write my own robust driver.If anyone has any documentation, logic analyzer captures, or insights regarding the J-A22/J-A24 protocol frame format, your guidance would be an absolute lifesaver for my thesis progress.Thank you so much for your time and expertise!Best regards,
lap
 Master's Student in Mechatronics Engineering

A bad workman blames his tools ...

Just a short rant how hard it is to setup this freaking card. Pnconfig wizard doesn´t work for it. You have to go the full manual way and it´s already a pain to get Mesa CT running and working. Some python needs to be installed, but thats a chapter by itself already. If you went through all the steps to finally get it recognized by Mesa CT and try to run that config with linuxcnc it doesn´t even find the card and exits with an error that the network isn´t reachable. I hate it so much i´ll throw it in the trash and go back to my 5i25 + 7i77. I´ll get a 5i26 for compability.

Hi, thanks for your help. Unfortunately, I misunderstood something last time. I have uploaded my complete LinuxCNC folder as an attachment.

LinuxCNC is 3.4.9.
I am using the gmoccapy interface with EtherCAT bus-controlled drives equipped with absolute encoders. The values HOME_OFFSET = 0 and HOME = 0 are set in my INI file. The zero point has already been configured on the drive, yet every time I boot LinuxCNC, the Xg54 position reading increases by 256 compared to the previous session.  why?

The switching to MDI mode is sometimes a limitation of linuxcnc.
There are a lot of 'manual' things that linuxcnc requires MDi for.

But it is also hard to predict what each users expects and also hard to control for whatever way a user sets up a machine.

Which tool probe are you using? versa, basic or the convenience button for touchoff?