That Input/output error is a generic one that means the serial port has disappeared from under the driver for some reason when it's trying to communicate with the device. Kernel log from that time might show if the device has reset itself for some reason (there is a watchdog in the ScopeDome controller that might be overly eager) or something else. Also having driver debug enabled in Ekos logging configuration before connecting to the device would show all serial port traffic the driver sends and responses it gets from the device.

Hello,
Yes you were right :
At the beginning, before the scopedome is connected I listed the ports and I found this for the scopedome :
lrwxrwxrwx 1 root root 13 janv. 4 18:26 usb-Arduino__www.arduino.cc__0042_95032303837351D04142-if00 -> ../../ttyACM1
I launch a command
While it is correct, I am looking at the ports and it does not change.

As soon as I get the error, i look at the port and I see it has changed :
lrwxrwxrwx 1 root root 13 janv. 4 18:36 usb-Arduino__www.arduino.cc__0042_95032303837351D04142-if00 -> ../../ttyACM0
How can I do to unchange the ports ?

to resume :
the ports before the error :
rwxrwxrwx 1 root root 13 janv. 4 18:26 usb-Arduino__www.arduino.cc__0042_95032303837351D04142-if00 -> ../../ttyACM1
lrwxrwxrwx 1 root root 13 janv. 4 18:26 usb-FTDI_FT232R_USB_UART_A10K713T-if00-port0 -> ../../ttyUSB1
lrwxrwxrwx 1 root root 13 janv. 4 18:18 usb-Prolific_Technology_Inc._USB-Serial_Controller_D-if00-port0 -> ../../ttyUSB0
lrwxrwxrwx 1 root root 13 janv. 4 18:26 usb-u-blox_AG_-_www.u-blox.com_u-blox_7_-_GPS_GNSS_Receiver-if00 -> ../../ttyACM2

the ports after the error:
lrwxrwxrwx 1 root root 13 janv. 4 18:36 usb-Arduino__www.arduino.cc__0042_95032303837351D04142-if00 -> ../../ttyACM0
lrwxrwxrwx 1 root root 13 janv. 4 18:36 usb-FTDI_FT232R_USB_UART_A10K713T-if00-port0 -> ../../ttyUSB1
lrwxrwxrwx 1 root root 13 janv. 4 18:18 usb-Prolific_Technology_Inc._USB-Serial_Controller_D-if00-port0 -> ../../ttyUSB0
lrwxrwxrwx 1 root root 13 janv. 4 18:36 usb-u-blox_AG_-_www.u-blox.com_u-blox_7_-_GPS_GNSS_Receiver-if00 -> ../../ttyACM2

the other ports do not change.

,

Here are the logs before the error and after the error

the second file

Hello again !
I reinstalled UBUNTU 22.04 and right after I reinstall INDI EKOS without anything else.
It's always very hard to connect the scopedome and while it is connected it finishes to change its port number ACM1 to ACM0
I can lauch some commands but it finishes to give errors ( getState etc....)
Yet I made udev
So I have /dev/scopedome witch points to /dev/ttyACM1 as a symbolic link
But after a while, it changes its ports to /dev/ACM0 and its finishes by errors And I cannot launch other command while there are errors.
I don't know what to do now.

Hello,
Now the port is changing in :
ls - l /dev
lrwxrwxrwx 1 root root 15 janv. 6 16:12 scopedome -> bus/usb/003/084

Cordialement
Sylvie

Please find the logs :
1- after not connected,
2- afterconnected
3- and error and the new ports

There is definitely something weird in your USB connections as all the USB-serial devices seem to get the same error for some reason. Are they connected to the same hub? Is the hub powered? Does kernel log (run command "sudo dmesg" on command line for example) show anything interesting when the error happens?

For ScopeDome there is also the possibility to use ethernet connection, I'm running out of ideas why the USB serials behave like that for you.

Hello,
I am going to connect evrything with ethernet
So I will tell you the result !
Thank you very much for your response

Actually I just now noticed that you have newer firmware (6.1) in your controller than what I used for testing originally (5.3, 5.4 and 5.7). Checking the Windows driver release notes there seems to be some issues with the connection too and they have increased the status query rate to every second for that reason, but that was the default in INDI driver already. You can try to play with the polling period setting, but I'm not too hopeful. It's currently also limited to once every 1-3s.

There is a hardware watchdog that resets the controller if it doesn't receive commands from ethernet for some time, so if that is on for some reason, that might cause this resetting thing even if the controller receives commands from serial port. The watchdog can be disabled with the Windows driver I think or by connecting to the serial port with some serial communication program like Minicom or Arduino IDE and sending command setEthWatchdog=0

Thank you very much
I am going to look at it

Hello
I installed raspberry pi4 between the PegasusUPB and the computer
So all the devices are connected to the PegasusUPB in USB and this USB is connected to the rapsberry
The computer connects via ethernet to the raspberry
The scopedome is directly connected to Ethernet 192.168.1.120
I had some problems because my ethernet box is in 192.168.0.xxx
So now all devices are connected
And the scopedome doesn't seem to show any errors
I made some tests and I will see when the weather will be ok as for the moment it is raining all days