Question

Hello,

we use a bunch of RUT 955. We have a strange problem with one of our RUTs. We have connected them to a serial device and using the TCP server to get readings.

Suddenly the transfer stopped, a reboot of the device has not helped. It seems the device has lost the RS232 serial port.

This is an output from the device with the problem:

dmesg | grep acm
[   12.360000] usbcore: registered new interface driver cdc_acm
[   12.360000] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters

ls /dev/
autofs              mtd0ro              mtdblock0           pts
bus                 mtd1                mtdblock1           random
cdc-wdm0            mtd1ro              mtdblock2           rs485
console             mtd2                mtdblock3           shm
cpu_dma_latency     mtd2ro              mtdblock4           tty
full                mtd3                mtdblock5           ttyATH0
fuse                mtd3ro              mtdblock6           ttyS0
gps                 mtd4                mtdblock7           ttyUSB0
kmsg                mtd4ro              net                 ttyUSB1
log                 mtd5                network_latency     ttyUSB2
mem                 mtd5ro              network_throughput  ttyUSB3
memory_bandwidth    mtd6                null                urandom
modem_cmd           mtd6ro              port                watchdog
modem_data          mtd7                ppp                 zero
mtd0                mtd7ro              ptmx

lsusb
Bus 001 Device 002: ID 05e3:0610
Bus 001 Device 001: ID 1d6b:0002
Bus 001 Device 003: ID 2c7c:0125

The working devices look much different:

dmesg | grep acm
[   12.500000] cdc_acm 1-1.3:1.0: This device cannot do calls on its own. It is not a modem.
[   12.500000] cdc_acm 1-1.3:1.0: ttyACM0: USB ACM device
[   12.550000] usbcore: registered new interface driver cdc_acm
[   12.550000] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters

ls /dev
autofs              modem_data          mtd6                network_latency     ttyATH0
bus                 mtd0                mtd6ro              network_throughput  ttyS0
cdc-wdm0            mtd0ro              mtd7                null                ttyUSB0
console             mtd1                mtd7ro              port                ttyUSB1
cpu_dma_latency     mtd1ro              mtdblock0           ppp                 ttyUSB2
full                mtd2                mtdblock1           ptmx                ttyUSB3
fuse                mtd2ro              mtdblock2           pts                 urandom
gps                 mtd3                mtdblock3           random              watchdog
kmsg                mtd3ro              mtdblock4           rs232               zero
log                 mtd4                mtdblock5           rs485
mem                 mtd4ro              mtdblock6           shm
memory_bandwidth    mtd5                mtdblock7           tty
modem_cmd           mtd5ro              net                 ttyACM0

lsusb
Bus 001 Device 002: ID 05e3:0610
Bus 001 Device 001: ID 1d6b:0002
Bus 001 Device 003: ID 04b4:0003
Bus 001 Device 004: ID 2c7c:0125

All devices running with the last release: RUT9XX_R_00.06.05.1

I have an access to the devices with SSH and web, but it is running at a remote location.

I would appreciate a hint how to get the RUT back to work.

Cheers and thank you in advanced.

Answer 1

Hello,

If RS232 does not start to function after device's reboot, this might indicate that there is an issue with device's RS232 configuration. First try to check if this "not working" RUT955 indeed has identical configuration to "working" RUT955.

If configurations seems identical, but one RUT955's RS232 still does not function, try to reset this device to factory default settings. After reset you will be able to reconfigure essential device's settings via SMS messages and reach it remotely again.

Device can be reset from "System -> Administration" menu by pressing "restore" button.

Few SMS commands, which might be relevant for you:

• shows device's status information. You will see if device established mobile data connection and what IP it acquired:
  • admin01 status
• enables HTTP / HTTPS remote access to device via its Public IP:
  • admin01 web   
• disabled "auto APN" fucntionality and sets APN (in case your SIM cards require specific APN to acquire Public IP address):
  • admin01 uci set simcard.sim1.auto_apn=0
  • admin01 uci set simcard.sim1.apn=newAPN
  • admin01 uci commit
  • admin01 reboot

Comments

Hello,

thank you very much for your support. We have had now the problem with two different locations and in both cases a reboot has resolved the problem.

We have double checked the RS232 settings and they match. At the moment we think, it could be an electrical issue with the wire or with voltage peaks.

Your tip with the factory reset is very much appreciated, we will try this the next time.

We will do some more investigation about the electrical issue and keep the forum posted.