Device status failure

[tronpusher]

Hi, having a problem connecting to the machine.

LAPTOP: Dell Latitude 5550, i5-5200U CPU @ 2.20GHz x 2
OPERATING SYSTEM: Linux Mint 21, Cinnamon 5.4.12, Kernel: 5.15.0-164-generic
APPLICATION: Universal G-Code Sender, Ver. 20251130
Firmware: GRBL, Port: ttyUSB0, Baud: 115200
MACHINE: Sainsmart Genmitsu PROVer XL 4030 v2

Computer is setup & operated as Single User with full system Permissions and Dialout group membership, ‘Brltty’ file deleted.
PROBLEM: Attempting to connect to machine -

***Connecting to jserialcomm://ttyUSB0: 115200
***Fetching device status

?
***Fetching device status (2 of 10)…
?
.
.
.
***Fetching device status (10 of 10)…
?
***Connection closed

Google AI suggested adjusting the ‘connection timeout', but I cant find the appropriate settings.

Thanks

[breiler]

Make sure you disconnect from the device from every program. Disconnect the controller and restart it, this is important if you want to use webserial.io.

Connect to it using one of these methods then just send blank lines (press enter) and it should respond with ok:

1. If you have Chrome you can use https://webserial.io/ to connect to the device.
2. Or else you can connect to it from a terminal with the command screen /dev/ttyUSB0 115200.(You exit this terminal with Ctrl-A then \)

If it doesn't respond with ok, see what happens if you send 0x18 reset command. It should respond with the GRBL welcome message:

1. In webserial.io, press the CAN button and press enter
2. In the terminal press Ctrl-X

[tronpusher]

Hi, thanks for the help. Terminal command (/dev/ttyUSB0 115200) returns "bash: /dev/ttyUSB0: Permission denied". Does this mean that I don't have Permission to access the ttyUSB0 port? Thanks

…

On Fri, Jan 23, 2026 at 10:58 PM Joacim Breiler ***@***.***> wrote: Make sure you disconnect from the device from every program. Disconnect the controller and restart it, this is important if you want to use webserial.io. Connect to it using one of these methods then just send blank lines (press enter) and it should respond with ok: 1. If you have Chrome you can use https://webserial.io/ to connect to the device. 2. Or else you can connect to it from a terminal with the command screen /dev/ttyUSB0 115200.(You exit this terminal with Ctrl-A then \) If it doesn't respond with ok, see what happens if you send 0x18 reset command. It should respond with the GRBL welcome message: 1. In webserial.io, press the CAN button and press enter 2. In the terminal press Ctrl-X — Reply to this email directly, view it on GitHub <#3008 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/B5H4T22YQRKJKBH6DUFWJM34IMJ2LAVCNFSM6AAAAACSXU3T2OVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTKNJYHA2TKMI> . You are receiving this because you authored the thread.Message ID: <winder/Universal-G-Code-Sender/repo-discussions/3008/comments/15588551@ github.com>

[breiler]

Have you rebooted your computer since you assigned your user to dialout group? If not, try that

[tronpusher]

Old PC builder, reboot after all installations and major settings changes. In the command: screen /dev/ttyUSB0 115200, 'screen' was not installed. It is installed now, however, the terminal window goes blank with the cursor either blinking or steady. Attempting to close the terminal window brings up the warning, "There is still a process running in this terminal. Closing the terminal will kill it."

…

On Sat, Jan 24, 2026 at 8:12 AM Joacim Breiler ***@***.***> wrote: Have you rebooted your computer since you assigned your user to dialout group? If not, try that — Reply to this email directly, view it on GitHub <#3008 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/B5H4T2YKZ77DQVWXOCBCAJD4IOKX5AVCNFSM6AAAAACSXU3T2OVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTKNJZGI2TMMQ> . You are receiving this because you authored the thread.Message ID: <winder/Universal-G-Code-Sender/repo-discussions/3008/comments/15592562@ github.com>

[tronpusher]

Now trying to run screen /dev/ttyUSB0 115200 in terminal returns [screen is terminating]. Trying to connect thru UGS brings up an error window "Error opening connection. Could not connect to controller on port jserialcomm://ttyUSB0:115200.

…

On Sat, Jan 24, 2026 at 9:22 AM Chris ***@***.***> wrote: Old PC builder, reboot after all installations and major settings changes. In the command: screen /dev/ttyUSB0 115200, 'screen' was not installed. It is installed now, however, the terminal window goes blank with the cursor either blinking or steady. Attempting to close the terminal window brings up the warning, "There is still a process running in this terminal. Closing the terminal will kill it." On Sat, Jan 24, 2026 at 8:12 AM Joacim Breiler ***@***.***> wrote: > Have you rebooted your computer since you assigned your user to dialout > group? If not, try that > > — > Reply to this email directly, view it on GitHub > <#3008 (reply in thread)>, > or unsubscribe > <https://github.com/notifications/unsubscribe-auth/B5H4T2YKZ77DQVWXOCBCAJD4IOKX5AVCNFSM6AAAAACSXU3T2OVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTKNJZGI2TMMQ> > . > You are receiving this because you authored the thread.Message ID: > <winder/Universal-G-Code-Sender/repo-discussions/3008/comments/15592562@ > github.com> >

[tronpusher]

SOLVED: It turns out that communications is disconnected when the Emergency Stop is down and locked, this fact is not mentioned anywhere in readily available documentation. I had the E-stop down as a safety. Thank you for time and assistance.