PRTG Manual: WMI Custom String Sensor

WQL File

Select a .wql file. The sensor executes it with every scanning interval.

The list contains WQL scripts that are available in the \Custom Sensors\WMI WQL scripts subfolder of the PRTG program directory on the probe system. Store your script there. If used on a cluster probe, you must store the file on all cluster nodes.

If the WQL query returns integers or floats, use the WMI Custom sensor to not only show the returned value in the sensor message, but to also monitor the value in a channel.

Sensor Name

Enter a name to identify the sensor. By default, PRTG shows this name in the device tree, as well as in alarms, logs, notifications, reports, maps, libraries, and tickets.

If the name contains angle brackets (<>), PRTG replaces them with braces ({}) for security reasons. For more information, see the Knowledge Base: What security features does PRTG include?

Parent Tags

Shows tags that the sensor inherits from its parent device, parent group, and parent probe.

This setting is for your information only. You cannot change it.

Tags

Enter one or more tags. Confirm each tag with the Spacebar key, a comma, or the Enter key. You can use tags to group objects and use tag-filtered views later on. Tags are not case-sensitive. Tags are automatically inherited.

It is not possible to enter tags with a leading plus (+) or minus (-) sign, nor tags with parentheses (()) or angle brackets (<>).

For performance reasons, it can take some minutes until you can filter for new tags that you added.

The sensor has the following default tags that are automatically predefined in the sensor's settings when you add the sensor:

• wmicustomsensor

Priority

Select a priority for the sensor. This setting determines the position of the sensor in lists. The highest priority is at the top of a list. Choose from the lowest priority () to the highest priority ().

Namespace

Enter the WMI namespace for the query.

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WQL File

Shows the .wql file that this sensor executes with every scanning interval.

PRTG shows this value for reference purposes only. If you need to change this value, add the sensor anew.

If the WQL query returns integers or floats, use the WMI Custom sensor to not only show the returned value in the sensor message, but to also monitor the value in a channel.

Placeholder <#PH1>

In your WQL script, you can use up to three placeholders to which you can assign a value in this field. Enter a string for variable <#PH1> or leave the field empty.

Placeholder <#PH2>

In your WQL script, you can use up to three placeholders to which you can assign a value in this field. Enter a string for variable <#PH2> or leave the field empty.

Placeholder <#PH3>

In your WQL script, you can use up to three placeholders to which you can assign a value in this field. Enter a string for variable <#PH3> or leave the field empty.

Unit String

Enter a unit for the data that the sensor receives from your script. This is for display purposes only. The unit is displayed in graphs and tables. Enter a string.

If Value Changes

Define what the sensor does when its value changes:

• Ignore (default): Do nothing.

• Trigger 'change' notification: Send an internal message that indicates a change.
  In combination with a change trigger, you can use this to trigger a notification if a change occurs.

Response Must Include (Down Status if Not Included)

Define the search string that must be part of the data that is received from the WMI object. You can enter a simple string in plain text or a regular expression.

The search string must be case sensitive.

If the data does not include the search pattern, the sensor shows the Down status.

Response Must Not Include (Down Status if Included)

Define the search string that must not be part of the data that is received from the WMI object. You can enter a simple string in plain text or a regular expression.

The search string must be case sensitive.

If the data does include the search pattern, the sensor shows the Down status.

Search Method

Define the method with which you want to provide the search string:

• Simple string search: Search for a simple string in plain text.

The characters * and ? work as placeholders. * stands for no number or any number of characters and ? stands for exactly one character. You cannot change this behavior. The literal search for these characters is only possible with a regex.

• Regular expression: Search with a regular expression (regex).

PRTG supports Perl Compatible Regular Expression (PCRE) regex. For more details, see section Regular Expressions.

Maximum String Length

Define the maximum allowed length of the string that is received from the WMI object. If it is longer than this value, the sensor shows the Down status. Enter an integer or leave the field empty.

Numeric Value Extraction

Define if you want to filter out a numeric value from the string received from the WMI object. You can convert this into a float value to use it with channel limits.

• Do not use extraction: Do not extract a float value. Use the result as a string value.
• Use a regular expression for extraction: Use a regex to identify a numeric value in the string and convert it to a float value. Define below.
  See also the example.

Regular Expression

This setting is only visible if you select Use a regular expression for extraction above. Enter a regex to identify the numeric value you want to extract from the string returned by the WMI object. You can use capturing groups here.

Make sure that the expression returns numbers only (including decimal and thousands separators). The result is further refined by the settings below.

PRTG supports Perl Compatible Regular Expression (PCRE) regex. For more details, see section Regular Expressions.

Index of Capturing Group

This setting is only visible if you select Use a regular expression for extraction above. If your regex uses capturing groups, specify which one captures the number. Enter an integer or leave the field empty.

Decimal Separator

This setting is only visible if you select Use a regular expression for extraction above. Define the character for the decimal separator of the number. Enter a string or leave the field empty.

Thousands Separator

This setting is only visible if you select Use a regular expression for extraction above. Define the character for the thousands separator of the number. Enter a string or leave the field empty.

Result Handling

Define what PRTG does with the sensor result:

• Discard result: Do not store the sensor result.

• Store result: Store the last sensor result in the \Logs\sensors subfolder of the PRTG data directory on the probe system. The file names are Result of Sensor [ID].txt and Result of Sensor [ID].Data.txt. This setting is for debugging purposes. PRTG overwrites these files with each scanning interval.

In a cluster, PRTG stores the result in the PRTG data directory of the master node.

Primary Channel

Select a channel from the list to define it as the primary channel. In the device tree, the last value of the primary channel is always displayed below the sensor's name. The available options depend on what channels are available for this sensor.

You can set a different primary channel later by clicking below a channel gauge on the sensor's Overview tab.

Graph Type

Define how different channels are shown for this sensor:

• Show channels independently (default): Show a graph for each channel.
• Stack channels on top of each other: Stack channels on top of each other to create a multi-channel graph. This generates a graph that visualizes the different components of your total traffic.
  You cannot use this option in combination with manual Vertical Axis Scaling (available in the channel settings).

Stack Unit

This setting is only visible if you enable Stack channels on top of each other as Graph Type. Select a unit from the list. All channels with this unit are stacked on top of each other. By default, you cannot exclude single channels from stacking if they use the selected unit. However, there is an advanced procedure to do so.

Downtime

In the channel table on the Overview tab, this channel never shows any values. PRTG uses this channel in graphs and reports to show the amount of time in which the sensor was in the Down status

Response Time

The response time

This channel is the primary channel by default.