RPi4 Mesa install: No 7C81 board found

Thanks. I will try using another cable. Is there any other way to connect the Mesa 7C81 with the Raspberry Pi 4? I have heard that you can connect the Mesa 7C81 using PNCoff, but I don’t understand how. If possible, could you explain it to me?

You can make a configuration with pncconf
(select 7c81-internal data, 5ABOBx3 firmware 
and run LinuxCNC with the created configuration file set)

(This may need the master version of LinuxCNC, not sure if
7C81 support is in 2.9.3)

I tried with longer jumper wires but got the same error. I have the 2.8.1 version of linuxcnc so I will try what you suggested. Thanks for the speedy responses