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Combining Sensors



I would like to combine two SMTP sensors so that an alarm is only generated in both sensors fail. We use two external SMTP sending services either of which are adequate for our needs. I only want to be alerted if BOTH of them are unavailable

and combination sensor smtp

Created on Feb 28, 2014 11:18:02 AM

3 Replies




This is a perfect usage scenario for the Sensor Factory Sensor:

  • Add a Sensor Factory to PRTG.
  • In Channel Definitions, provide the IDs of the desired sensors and channels, for example:
#1:SMTP 1
Channel(<sensor ID of the first SMTP sensor>,<channel ID of this SMTP's primary channel>)

#2:SMTP 2
Channel(<sensor ID of the second SMTP sensor>,<channel ID of this SMTP's primary channel>)
  • In section Error Handling, choose Use custom formula.
  • Use the status() function with boolean operators to determine one status for both sensors. You only need to provide the sensor IDs of your SMTP sensors:
status(<sensor ID of first SMTP sensor>) AND status(<sensor ID of second SMTP sensor>)
  • Define the "no data" behavior and Save.

The custom status formula means that the overall status of the Sensor Factory will only turn red if both SMTP sensors are down.

Created on Feb 28, 2014 2:03:31 PM by  Gerald Schoch [Paessler Support]

Last change on Feb 28, 2014 2:05:03 PM by  Gerald Schoch [Paessler Support]



That's great and i have created the Sensor factory sensor . it seams to be working.

Please correct me

1) Which device do I connect the sensor to .I have connected it to one of the two SMTP sending services (Seems to work) 2) The reason needed this because I only wanted to be alerted when both/all sensors fail. How do I continue to monitor these sensors but stop them from producing a red


Created on Feb 28, 2014 3:56:10 PM



You can add the Sensor Factory to any device in your PRTG installation but there is no way to stop your SMTP sensors "producing a red" except fixing the error—if there is an error, PRTG will show this error likewise. But if you have created a Sensor Factory as described above, the status of the Sensor Factory will still be green if only one of your SMTP sensors fails.

Created on Feb 28, 2014 5:57:15 PM by  Gerald Schoch [Paessler Support]

Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.