The "Trigger Count" simply sets, how many times in a row the measured value needs to exceed the threshold for finally triggering the command execution.
After the command was executed or if the measurement falls beneath the threshold the count is reset.
So, e.g.: you set trigger count to 3 and trigger value to, lets say, 100 then for the given, imaginary measured values the count would be as follows:
Values: 75, 101, 54, 89, 103, 105, 101, 102, 101, 67
Count: _0, __1, _0, _0, __1, __2, __3, __X, __1, _0

In this example 'X' represents command execution and reset of the count to zero.
Edit: Also note that the terminology might be confusing.
"Trigger Count" is the setting which determines when commands are executed and "count" (or maybe "running count" would be a better term) is the actual "counted" value at runtime that is compared to the "Trigger Count" setting for actually determining whether a command should be executed.

I hope the example is readable in all browsers.