PRTG Manual: SNMP Custom Sensor

Channel Name

Enter a name for the channel in which the sensor shows the results for the OID. Enter a string.

You can change this value later in the channel settings of this sensor.

Value Type

Select the expected numeric type of the results at the OID:

▪Absolute (unsigned integer): Integers without an operational sign, such as 10 or 120.

▪Absolute (signed integer): Integers with an operational sign, such as -12 or 120.

▪Absolute (float): Float values, such as -5.80 or 8.23.

▪Delta (counter): Counter values. PRTG calculates the difference between the last and the current value. PRTG additionally divides the delta value by a time period to indicate a speed value.
This mode only works if the difference between the last and the current value is positive and increases with each scanning interval. This mode does not support negative values and decreasing values.

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

Unit String

Enter the unit for the values that this sensor returns. Enter a string. PRTG uses the unit string for display purposes and shows it in graphs, data tables, and gauges.

If you want to change the unit after sensor creation, you can change it in the sensor's channel settings.

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:

▪snmpcustomsensor

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 ().

OID

Enter the OID of the SNMP object that you want to receive numeric data from.

Most OIDs begin with 1.3.6.1. However, OIDs that start with 1.0, or 1.1, or 1.2 are also allowed. If you want to entirely disable the validation of your entry, add the string norfccheck: to the beginning of the OID, for example, norfccheck:2.0.0.0.1.

Value Type

Shows the value type of the numeric data that this sensor receives from the OID.

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

Multiplication

If you want to multiply the received data with a certain value, enter the multiplier. Use the default value 1 to not change the received value. Enter an integer.

Division

If you want to divide the received data by a certain value, enter the divisor. Use the default value 1 to not change the received value. Enter an integer.

If Value Changes

Define what the sensor does when the sensor value changes:

▪Ignore changes (default): Do nothing.

▪Trigger 'change' notification: Send an internal message indicating that the sensor value has changed. In combination with a change trigger, you can use this mechanism to trigger a notification whenever the sensor value changes.

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

[Value]

The single numeric value (int64) for a specified OID

This channel is the primary channel by default.