Create new rule to find disconnected network card in VM machines


I am trying to make a new alarm that will be activated if my VM machine will lose its network card.
I am trying to think what is the best way to do it.

The way that I found, is to create a new rule. under "Rule Definition" console if I put "" I get in the "Conditions, Alarms & Actions" console under "Run Condition Query" the count of how many network cards I have on every VM. but the problem that I did not get machines with 0 network card. and if I search "VMWVirtualMachine : network.interfaces == null" on the "Rule Definition" console I get zero VM machines (and I create few VM without network card for the test, so clearly I have a problem...)

I would appreciate if anyone could help me.

In addition, someone can post here a link with information about syntax in the "Conditions, Alarms & Actions" console.

Menahem Avraham