A Data Point is a collection of associated historical values. For example, a particular point might be a temperature reading from a room, while another point could be the humidity reading from the same room. Points can also be control values, such as a switch to turn a piece of equipment on or off.
There are many attributes that are used to control the behavior of points, but can be separated into two groups. First, there is the concept of a Point Locator. Locators are used by Data Source to determine how to “find” the data for the particular point. For instance, the Point Locator of an SQL Data Point indicates the table and field names with which to find its specific value from the query.
Second, Data Point attributes also determine many other aspects of the point, such as its name, how/when it should be logged into the database, how long to keep logged data, how to render values for display, and how to chart values. These attributes are common to all Data Points, although a particular data type may or may not have them all.
You can also configure Data Points with Event Detectors, which are used to detect conditions of interest in points’ values, such as the value being too high/low for too long, changing too often, not changing at often enough, etc.
Data Types
There are five supported data types:
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Binary values have only two states, referred to in the system as the zero value and the one value. You can use a Text Renderer to convert the display of binary values to whatever alternate labels you need, such as “on/off”, “high/ low”, “started/stopped”, etc.
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Multistate values have multiple distinct states. Values are primitively represented as integers (e.g. 0, 1, 2, 7, ...), but also have Text Renderer options to convert these values to appropriate textual representations such as “on/ off/disabled”, “cool/heat/off”, or anything else.
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Numeric values are decimal values represented in the system with a floating point variable. Temperature, humidity, price, and altitude are examples of numeric values. Text Renderers can be used to determine display features like how many decimals places to display, whether to separate thousands (with commas or dots), and whether a suffix should be displayed (e.g. °F, kW/h, moles, etc). The “Range” type of Text Renderer can be used to convert ranges of numeric values into text labels.
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Alphanumeric values are simply strings of characters, such as the O/S description of an SNMP source.