Hello,
This exception is raised when the binding asks from openHAB core the serial port, and openHAB returns nothing. So this is a “global” issue, not directly related to the binding.
(I want to be precise here, because if we cannot manage to help you here, you can ask in the more general part of this community forum)
That said, did you see this openHAB page ? There are other advices to make the serial communication works.
Hello,
I saw this page, but I overlooked /var/lock article.
So for el8 systems is needed add permissions:
chgrp lock /run/lock
chmod g+w /run/lock
and binding running.
Thanks a lot,
PM.
Is planned extension for dialing? For urgent triggers may be usable ringing phone instead notification. ATD command can be easier than SMS.
I didn’t even know it was possible !
It could be very fun to add, especially with the voice/multimedia functionnality of openHAB.
With STT and TTS and dialog processing, you could imagine talking to your openHAB with a simple voice call…
But unfortunately it’s not on the library I use for modem processing, so it means I would have to dig and code this and test… I will add this to my todo/fun list, but let’s be honest, this list is at the moment way too long 
As usual, anybody is welcome to open a PR and I will be glad to help with testing and reviewing.
I don’t know howto you call AT commands for SMS, but I’d like use dialing only for ringing my phone, and then without voice processing may be work quite easier, maybe simplified as message processing. Ther will be only DIALING, CALL and HANGING signals.
Hi,
first: your Binding is really interesting. Thanks for your work.
I was able to receive SMS with my modem, but I’m not able to send some.
Always I got the following error message:
[WARN ] [rg.smslib.driver.AbstractModemDriver] - /dev/ttyUSB0:4800 ERR==> +CMS ERROR: 500
I tried to change the Baud Rate, the format of the telephone number, but nothing works.
Could you or someone help me?
Regards,
Inc.
Check if your modem knows its IMSI (AT+CIMI=? or AT+CIMI).
Check the SIM card account balance. 
WOW, thanks a lot.
You are totally right. It was the balance. In Germany the budget expires, when you put not new money on the account for a year. It works great!