Customizing alert-settings on specific nodes

Hi,

In our network we have a couple of nodes with a normal response time of about 160ms (never lower than 140ms, peaks at 1000ms)

With the default setting for alerting on high response time this caused trouble since the alarm was triggered when Rtime over 200ms, but it would never reset because it would have to go below 100ms to do so.

I now have changed the reset conditions for the alarm to: "when under 200ms".

Yet, still our event-list is flooded with alert triggered and reset, triggered and reset, and so on from these nodes. Kind of annoying.

The question is therefore:

Is there any way that I can specify that the alarm should not be triggered for these two nodes unless its response time has stayed over 200ms for at least 5 minutes?

Thanks,

Simon