Hi we have quite a few stations being polled by multiple dial-up modems and we are having trouble with them locking up.
Basically what happens is sometimes the "+++" disconnect command does not work and the modems stay in "data mode" which causes the modem to become unresponsive until it is manually reset.
I have tried changing the modems D0 variable to D2 to disconnect with DTR, however DTR does not seem to go low (or it is extremely quick) when Loggernet tries to disconnect.
Is there a way to setup Loggernet to control DTR?
Thanks
CJ
Is it the base modem or the remote modem that stays in data mode? If it is the remote, you could reset it once per day as a work around, not elegant I know but...
Another thing to try that worked for us recently was to increase the "delay hangup" to 200ms in all setup screens. This worked for us recently with some satellite modem issues.
Cheers
Grant
Thanks Grant I'll give that a try.
I have seen this problem too with some base modems. In some cases this is caused by the settings in the modem, in respect of the "guard time" which is the time required before and after the +++ to enable the modem to recognise the attempt to break in. This is normally controlled by S register 12 in a Hayes compatible modem. Loggernet assumes a setting equivalent to one second, which used to be the standard setting.
There is no way to change the delay Loggernet allows, although adding the delay before hangup may extend the time before the +++. You could change the register setting in the modem though to a shorter time.
Alternatively, you could instead of using Loggernet's own modem driver, use the TAPI interface. This uses the Windows driver for the modem, which is controlled by information provided by the modem manufacturer on the best way to control the modem, e.g. hangup. This may give you more certainty of hanging up the call although the TAPI interface (at the Windows level) does seem to have longer timeouts etc, which can make aborting bad connections or manually hanging up calls take longer.
We have had a problem with unresponsive phone/modems in the past. We were never sure if the problem with the phone hardware or the service provider but the solution was to shut the phone off for 5-10 minutes once a day. That forced the phone and the network to re-establish a clean connection.
The phone power was controlled through a low power relay connected to a digital I/O port. We have used some small mechanical relays but most often used a solid state relay from Crydom. They cost a bit more but drew very little power and could control over 30 amps DC.
I also program my remote stations to power cycle the modem daily at midnight for 1 minute(used the switch 12 vdc to power the modem), this took care of some connection issues as rlwoell mentioned.