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Parent Topic: Learn More about Server Fundamentals
Tags are internal storage containers where devices and NI InsightCM Server read and write values. An example of a value stored in a tag is the most recent RMS value from acceleration data that a particular channel acquires. The internal alarm service can read the value of this tag and set an alarm. The historian services can also read this value and write it to historian software. Other examples of tags include the amount of memory available on a device and the status of each channel, such as open, short, or ok.
When you add a new alarm rule or PI point mapping, you must identify the component that serves as the source of values. You select an NI InsightCM Server tag to serve as the source.
You might also need to understand tag names to perform additional tasks, as the next section describes.
Each tag has a unique name, delimited by vertical bars (pipes), that identifies it. For example, the following tag corresponds to the RMS value from acceleration data that a particular sensor acquires: Unit 1|Motor|Accelerometer|RMS.
You typically do not need to know or manually enter tag names because they are predefined. However, you need to manually enter names for unpublished tags because the dialog boxes you use to create alarms and point mappings list only published tags. For example, consider a device that has not yet connected to NI InsightCM Server. If you want to add an alarm rule whose source is RMS values from a sensor on the device, you must manually enter the path to which the RMS values will be published. Refer to Defining Names for Tags That Are Not Published.