Operating system name and version: Linux 2.6.28-19-generic Gecko/20101013 Ubuntu/9.04 (jaunty) x86_64 GNU/Linux
Version of smsd: 3.1.14
Smsd installed from: sources
Name and model of a modem / phone: 3x Huawei Technologies Co., Ltd. E620 USB Modem (VODAFONE MODEM)
Interface: USB


Hello,
I am new to smsd and trying to make it work with the above 3 modems just for receiving sms
The problem is that I can only receive sms on 2 of the 3 modems regardless of the configuration/connections.
I tried to change the connections, switch the modems around, connect them to a hub, or directly to the PC or a combination of both.
I switched the SIM cards, and even went on checking if the cards are receiving the proper Voltage/Amperage...
In other words I tried everything I can think of.
The modem that receives the sms are not always the same ones and not always the ones I connect first so sometimes it is modem connected on /dev/ttyUSB0 and USB6 or USB3 and USBt6 or 1 and 6 ...
Any way it seems that I am unable to understand the problem.
I also tried different baudrate...And dont remember what else I also tried, it has been a week now
here is a copy of the smsd.conf (I am surely missing something) and a part of one of the logs "GSM1_trouble.log" where an error was reported after receiving an sms, same error was reported on the second modem (though this error is casual)

Dose any one got any suggestion or can help?

Thank you in advance.
Best regards.



GSM1_trouble.log

2010-12-03 00:20:00,7, GSM1: -> AT 2010-12-03 00:20:00,7, GSM1: Command is sent, waiting for the answer 2010-12-03 00:20:05,7, GSM1: put_command expected (OK)|(ERROR), timeout occurred. 1. 2010-12-03 00:20:05,7, GSM1: <- 2010-12-03 00:20:05,7, GSM1: -> .

I am still trying to understand the issue with no luck.
Any one got an idea or have faced a similar situation?
Thank you

When you tried with a hub, did it have an external power supply, or was it just connected to the PC and using the power from single USB port? When the modem is idle, it does not draw very much current, but when it is communicating with the network, it draws much more.

Hello Keke,
I tried it with 2 different hubs,
one without external power and the second with a 5v 0.8A external power.
Always the same problem.
I am wondering if the 0.8A are enough to power the 3 cards, since as I read each card needs 0.5mA
But electronics is not my major so i am trying my best to figure it out.

Now I am sure that it is not a powering problem, or at least I think.
Modems where connected on 3 different hubs with external powers

I just would like to know if the is something in the config I could modify/add/remove?

Other wise, has some one experienced smsd with more than 2 modems? and would it possible to post a copy or overview of his/her settings please?

Thank you.

Your configuration is good. Also there is no available any setting which may cause or resolve this kind of a problem. The modem stops responding, and smsd does not cause it and cannot do anything for it.

In some systems smsd is used with more than 30 modems in one server. Also USB modems have been used. The number of modems is not a problem.

You could ensure that in your system there is no any other process which may communicate with modems. Those modems are mainly purposed for networking, but in this case any external software or driver is not required. I however assume that this is not the problem.

0.5 mA is very low value, likely it's the "idle" current. Typically when USB modem is sending data to the GSM network, it draws something about 250 - 300 mA current (peak) or even more. If your power supply is well stabilized, this should not be a problem.

When you run only two modems, there are no any errors even in the long run, right? After you plugged in third modem, random one of those modems stops responding. I do not remember any other this kind of situation. A member lextor had troubles with three Huawei sticks, but in that case the trouble was caused by the GSM network. All modems communicated properly with smsd, but the sending was slow and failed in some cases when multiple modems was used and lot of messages was sent.

When the problem occurs, how close those modems are to each other? I think that at least 20 cm gap is enough, but more is better. I use about 30-40 cm for external antennas, and have no troubles.

Do you have any other server in the same machine room, near to your Ubuntu server? If you have, you could run two modems with Ubuntu, and third modem with another server. This may detect if the problem is caused by the GSM network.

Hello Keke,

I have solved the problem.

One of the modems was defected, in fact I was able to communicate with it using at command, and even sometimes receives sms, but it was random.
So this was the problem.

I replaced the defected modem, got a new better hub, placed the modems away from each other and now it is working.

Thank you again for the support.

You can consider this post as solved.

Best regards.