How to Set Channel Limits
In this video, you’re going to learn how to configure channel limits in PRTG. The channel limits are the upper and lower threshold limits, where you would like your sensors to go into warning or error state, so you can get a notification when something goes wrong. You can set customized limits for every channel on every sensor you’ve got, although we recommend only setting limits on your most important sensors and channels, to avoid being flooded with alerts. To set limits, go to the sensor and then click on the little gear icon below the relevant channel. In the window that now pops up, at the bottom of the list, select “Enable Limits”. The window will now expand to give you six new fields, where you can enter the upper and lower limits, for both warning and error state. All of these fields are optional, so you only need to fill in those where it makes sense. In this case, which is a sensor for CPU load, upper limits are important for when the CPU load is high, but lower limits don’t make much sense, because I don’t want an error when CPU usage is low. So, in this case, you could fill in an upper error limit of, say, 80%, and an upper warning limit of 60%. And for this example we can just leave the lower limits blank. If you want to, you can add a text message to display when these limits are reached. • CPU usage is too high • CPU usage is getting rather high Then, Apply the changes, and click OK to close this window. This takes you back to the sensor page, and you can see that the gauge for this channel has updated, to indicate where we’ve just set the warning and error limits. And that’s it – you now have threshold limits set for this channel. If you need to set channel limits for multiple sensors, not only one, you don’t need to go through every sensor manually. You can either use templates to create new sensors with the limits already pre-configured. Or, if the sensors already exist, you can use the Management tab, or multi-edit, to configure limits for multiple sensors at the same time. Using the management tab, control-click to select multiple sensors. The settings that these sensors have in common will be displayed on the right. Switch to the channel settings, select a channel, and scroll down to the Limits section. Changing the settings here will change them for all of the sensors that are currently selected. If the sensors are spread throughout the tree and are thus hard to find in the management view, you can also get a list of sensors by Type or by Tag, in the Sensors Menu. This gives you a list of all the sensors of that type or with that tag. You can then select or deselect the ones you want with the checkboxes on the right, and then go to the little down arrow and select Settings. Similar to the management view we just saw, you will now see a list of the settings that these sensors have in common. Switch to channel settings, select a channel, and then set the channel limits here. This will change the limits for all of the sensors that were selected in the list. Now, if you’d like to get alerts when values cross your limits, you can now set up triggers and notifications for these sensors.