Pay as you go SIMs can be disabled -- please check

Most temperature monitoring equipment is purchased in order for you to be alerted when things go wrong. Quite often you want to be alerted using SMS.

Many of you use the z-text fixed line SMS modem for this performing the SMS end of the alerting. If that is you, you can stop reading right now because this doesn’t apply to you.

If you are using a GSM based modem, like the Falcom 55 & 75, you need to make sure that your particular SIM won’t time out. Some GSM network operators disable their pay as you go customers after a certain amount of activity.

Given the nature of monitoring, most of the time nothing much happens. Everything works as expected so no alerts are generated. That can mean that, to a GSM network operator, your SIM doesn’t look very active. Your operator may disable your SIM.

Obviously, if you try to send a SMS message using a disabled SIM card, it isn’t going to work. Please check with your SIM card provider to make sure that they will not disable your SIM due to inactivity.