Ya not normal and not something that ever happens when things are working correctly.
It is possibly some fault caused by the alarm panel connection like low voltage etc or voltage spikes caused by power problems or something may be misconfigured etc. We will need to get more information to find the fault.
Lets get the abvious out of the way first and start gathering more data when the problem happens since it seems to happen seldomely and not predictbaly.
* Send a dump of your AD2* configuration including version data and all settings.
* If you have any logging from the AD2* especially showing the beeping. The beeping should be indicated in the actual messages from the alarm panel that the AD2* will send to the computer. This may also contain fault codes from the panel in the message.
* describe your connections from panel to AD2* and from AD2* to what type of computer and what type of home automation system. This will help us figure out what tools we can use to do further debugging and if any potential ground faults may be present.
* when this happens record the LED heartbeat activity on the AD2* before you do anyting to the panel and confirm that it is flashing its normal beat or not.
Depending on how this goes we may send you a test unit so please open up a ticket with our servers by emailing
ad2usb@support.nutech.com with your details referencing this forum post.
In any case we will get if figured out without a doubt just going to take a little time considering the nature of the problem.
Re
Sean M