Trigger ICMP unreachable 3 times in 5 sec

[uknet800]

Hello to everyone,

I want to ping a host for 3 times for a duration of 5 minutes. I added below expression

"Number of successfully retrieved values V for period of time T > N"

{file-server.local:icmpping.count(600,0)}>3

This suppose to be true if host “file-server.local” is unreachable more than 3 times in the last 5 minutes.

But it doesn't work??

My Zabbix Version is:
Zabbix Server v1.8.3 (revision 13928) (16 August 2010)

Ideas would be appreciated.

Thanks