Advanced Custom XML sensor

Hello All,
With the sensor above a powershell script is querying several remote windows services. It successfully return value but and values are showed in the channel. My problems is how can I set the channel in error state? actually are always in green status. Below the XML output-.
Tried also adding tag <error></error> no changes.

Thanks,

<PRTG>
  <result>
    <channel>WINDOWS_SERVICE</channel>
    <value>0</value>
  </result>
  <result>
    <channel>WINDOWS_SERVICE</channel>
    <value>0</value>
  </result>
  <result>
    <channel>WINDOWS_SERVICE</channel>
    <value>0</value>
  </result>
  <result>
    <channel>WINDOWS_SERVICE</channel>
    <value>0</value>
  </result>
  <result>
    <channel>WINDOWS_SERVICE</channel>
    <value>0</value>
  </result>
  <result>
    <channel>WINDOWS_SERVICE</channel>
    <value>2</value>
  </result>
  <result>
    <channel>WINDOWS_SERVICE</channel>
    <value>0</value>
  </result>
  <result>
    <channel>WINDOWS_SERVICE</channel>
    <value>0</value>
  </result>
  <result>
    <channel>WINDOWS_SERVICE</channel>
    <value>0</value>
  </result>
  <result>
    <channel>WINDOWS_SERVICE</channel>
    <value>0</value>
  </result>
  <result>
    <channel>WINDOWS_SERVICE</channel>
    <value>0</value>
  </result>
  <result>
    <channel>WINDOWS_SERVICE</channel>
    <value>0</value>
  </result>
</PRTG>

#customsensors #powershell #xml