Changes in Android’s operating system are due to the fact that on some phones it is not possible to receive voice alarms when Ontech alerts. An alternative could be to set a special sound instead when SMS arrives from an Ontech telephone number. You do this completely outside the app. See also this link:

How to set custom text tones for your contacts on Android

There are GSM antennas with cable that allow you to place the antenna a bit away from the device and thus look for the best antenna location. It must be a GSM antenna and it must have an SMA-type male connector.

In Android 6, you must agree that the app may send SMS or the application will stop. You can do this by:
Go to Settings / Programs / Program Manager / Ontech. Then allow SMS and right to read.

Verify

1. That the PIN code has been removed from the SIM card.

2. That there is a contact on the SIM card called PINCODE and where there is a four-digit number in the field for the phone number. Often it is necessary to manually copy to SIM card, otherwise it will only be stored in the phone’s memory.

3. When trying to make a voice call with the SIM card when it is inserted in a mobile phone, it is important that someone answers at the other end so that the welcome message disappears.

If the error still persists, it may be the GSM module that is not working. When the telecom operator “closes” a SIM card, a code is sent that may cause the Ontech GSM module to crash. This has to be replaced. Contact support@ontechgsm.com in that case.