Unable to connect to The EHS6T after 2 days | Telit Cinterion IoT Developer Community
June 30, 2022 - 1:41pm, 1071 views
I'm using EHS6T device for USSD sessions and it works greatly.
The issue, Modem hangs after a while and cannot accept Telnet on port 1234 connections anymore.
Without disabling power saving , it hangs after some hours. When I disable Power Saving Mode, device hangs after 2-3 Days. When trying to connect the response is "none".
Please, need your help to fix this because I need to have device connected permanently 24/24 7/7.
Do you mean AT^SPOW setting? This should affect RS232 interface only. Do you access the device via a serial interface also?
The module is connected to OpenWrt system over USB inside. You can connect to the module via RS232 and check if it replies to AT commands locally. And how about SSH - does it still work? Can you get to OpenWrt system? Then you could debug the USB. Is WAN connection used?
Is it a single device that fails that way or you have more which also fail or maybe work well?
Thanks for your reply.
Yes AT^SPOW settings. I access to Device via LAN only. While I can't connect to AT port, Device respond normally to SSH login ans I can access OpenWrt as well. Only Telnet to AT port (1234) failed.
This model I have doesn't have usb port. LAN and RS232 only.
I'm using 2 devices and both have the same issue.
Here are logs from OpenWrt while AT connxion failed.
Fri Jul 1 08:17:18 2022 ******.notice pppd: pppd 2.4.7 started by root, uid 0
Fri Jul 1 08:17:23 2022 kern.err kernel: [80636.910000] cdc_acm 1-1:1.8: failed to set dtr/rts
Fri Jul 1 08:17:24 2022 kern.err kernel: [80637.680000] cdc_acm 1-1:1.6: failed to set dtr/rts
Fri Jul 1 08:17:29 2022 ******.err ser2net: Could not turn off break for device /dev/ttyACM3 port 1234: Connection timed out
Fri Jul 1 08:17:34 2022 ******.err pppd: Connect script failed
Fri Jul 1 08:17:45 2022 ******.info pppd: Exit.
Fri Jul 1 08:17:45 2022 kern.err kernel: [80658.920000] cdc_acm 1-1:1.8: failed to set dtr/rts
Fri Jul 1 08:17:45 2022 ******.notice netifd: Interface '3gwan' is now down
Fri Jul 1 08:17:45 2022 ******.notice netifd: Interface '3gwan' is setting up now
Fri Jul 1 08:17:50 2022 kern.err kernel: [80664.060000] cdc_acm 1-1:1.8: failed to set dtr/rts
Fri Jul 1 08:18:04 2022 kern.err kernel: [80677.820000] cdc_acm 1-1:1.6: failed to set dtr/rts
Fri Jul 1 08:18:09 2022 ******.err ser2net: Could not turn off break for device /dev/ttyACM3 port 1234: Connection timed out
Fri Jul 1 08:18:37 2022 kern.err kernel: [80710.640000] cdc_acm 1-1:1.8: failed to set dtr/rts
Fri Jul 1 08:18:42 2022 kern.err kernel: [80715.700000] cdc_acm 1-1:1.8: failed to set dtr/rts
Fri Jul 1 08:18:49 2022 kern.err kernel: [80722.990000] cdc_acm 1-1:1.6: failed to set dtr/rts
Fri Jul 1 08:18:54 2022 ******.err ser2net: Could not turn off break for device /dev/ttyACM3 port 1234: Connection timed out
Hope it could help.
The module has one USB interface. In case of LAN terminal this USB is used for the internal connection between the module and the processor on which OpenWrt is running. So you have only RS232 port on the casing to connect to the module directly and check if it's alive. You need to set AT^SPOW=1,0,0 (you may do it over Telnet) to make sure that the interface is enabled. Also you may need to check AT^SCFG output to make sure that no userware output is set to ASC0.
Please also check the running processes and find ser2net which is responsible for bridging one of the virtual USB interfaces to Telnet. Check the configuration file contents to see which interface is used for that. Then check logread again for this interface events or ser2net also. Pleas try to restart ser2net process and check.
And in your log it seems like pppd failed.Do you use the wan connection in your terminal or it is only for USSD? If PPP connection is not necessary you may switch it off. it is on by default as the main purpose of this terminal is to provide the WAN connection.
This failed to set dtr/rts sounds strange as if the module was down for example. So, it would be good to verify on the physical RS232 interface if it's working. But if it's not you would also find some evidence in logread output.
Thank you so much for your help.
I think the problem was the PPPD connection. I removed the 3GWAN interface and Modems are available for USSD commands since 5 days without issue.
Meanwhile, please, how to disable pppd without removing the 3GWAN interface?
You could do it easily via web interface, connecting with the browser to the terminal's IP.
Hello Dear Bartłomiej,
Modem were working fine until last week and cdc_acm 1-1:1.10: failed to set dtr/rts issue start again. I didn't make any change on modem's configuration.
I can access Modem by Web interface and SSH but AT Commands failed.
Please, for ser2net process how to restart the single process without restart modem? I checked in /etc/init.d/ and couldn't find the script which stat that process.
Also do you thin the coreutils-stty package installation could help fixing this issue?
are use able to connect to module RS232 port and check if it's responding to commands?
Is the dtr/rts problem constant or periodical?
I need to check on how to reset ser2net and about coreutils-stty package update
The modem is already in LAN and can't access Serial to test AT Command without powering of it when problem occur.
The dtr/rts problem occur time to time. At beginning it occur after around 2 days and after I disabled PPP, it was working for 1 week without issue but since last week it failed after 2 days again.
The curios thing is that I didn't change any Modem configuration recently and can't understand why the issue resumed.