Operating system name and version: openwrt, clone trunk
Version of smsd: 3.x
Smsd installed from: buildroot
Name and model of a modem / phone: chinese lte module, work trough cdc-acm driver and an rndis driver
Interface: smsd configured on ttyACM1

Hello,

I'm facing a problem and I hope you can help me.
The smstools works well but it seems that it locks the device, ttyACM1 (the only interface to send at command).
In my system sometimes and incoming sms could ask to connect or disconnect the pdp context from network. The incoming sms is handled with eventhandler, and an app starts. So my question is simple how can i send at comand while demon is running? Is there an option to say receive and release the tty?
Or maybe, based on your experience, the better solution is to attach a cmux driver on ttyACM1 (I hope the modem support it)? but exist a cmux driver for linux?

Thanks

There are two ways to send AT commands while daemon is running. See the documentation of regular_run settings.

1) Use a modem setting regular_run = /path/to/your/script. Create a script which sends commands when a flag file exists. Create that flag file in eventhandler when connect/disconnect is asked. This external script can use the modem, as it is closed when the script is executed.

2) Use a modem setting regular_run_cmdfile = /var/spool/sms/GSM1.cmd. In eventhandler create this file with proper command. When this file exists, smsd will send commands to the modem and deletes the file. No flag files and external scripts are required.

In both cases a modem setting regular_run_interval = 1 is necessary to make the commands run quickly enough.