Look that my trigger wait iregexp == "red", but I was a event alert when my iregexp == green.
Should generate an event only when the return was red, not green.
The problem, can be seen in Attachment the image files.

Trigger:

{Template VMware vSphere Virtual Machine - vPoller with C client:cvpoller-zabbix["-m", "vm.get", "-V", "{$VSPHERE.HOST}", "-n", "{HOST.NAME}", "-p", "summary.overallStatus"].iregexp(red,5)}=1