Hi Roger,
I have an installation with an S3 DT50 and a SMSX modem. The customer cannot always dial into the system. Every so often (could be once a week could be once a month) the comms link between the logger and the smsx unit seems to go awol.

The only remedy seems to be to power down and up again the SMSX and to plug in a laptop to DT50 and try to connect a few times. The connection doesn't happen first time.

I suspect that the comms between the modem and the DT50 are remaining open even though the line has been dropped. Is this a common problem?

I think I remember reading something before about the logger and the modem echoing messages back and forth endlessly under certain circumstances. I have a couple of Promod7 cables in stock.

Would this help do you think or is it possible the DTR line on the SMSX module would stay active even though the line is dropped? If so is the promod7 connection kept active the DTR?

Regards,
Chris

Hi Chris,

A regular reset of the modem done through datataker's digital output may help. This may be done once a day (at midnight for example). It remains strange that the logger still unreachable at the first attempt in the "local" connection (may the logger still in sleep mode?). I don't think that mod7 cable is suitable for the use with SMSX modem.

Roger correct me if I'm wrong...

Bye

Teo,

Thanks for the input. I don't like powering the modem off with a relay like that because you have to tell customers why your doing it. In this case the problem does not disappear by just resetting the modem the logger seems to wait for a disconnect. You have to try to connect a few times until the port comes active again.

I have seen this on other sites and think it is to do with the SMSX not closing the port down and stuff bouncing back and forth(maybe leaving result codes or echo on). The connection could be forced to close using the active promod-7 cable (I think).

I suppose the best thing to do is set one up and try it out. I can't see why this cable wouldn't work with the SMSX just like any old modem. But maybe it will be of no additional benefit either. It's just a fallback I'd like to have if needed.

I can buy cables but not time so if it turns out more reliable then its better for me.

Best Regards,
Chris

Hi Chris,

I suppose that mod7 could not use with SMSX modem just because, to send sms messages, the connected dataTaker has to send string to instruct the SMSX modem. If SMSX modem is use as a standard AT modem, I mean, just to download data, the mod7 cable should be used and I think (never tried with SMSX modem) will offer all the benefits it claims and you are searching for.

Bye

Teo,

Yes exactly. I have no need for the sms alarm features so only need to use AT commands.

Well observed,
Chris