Value Match allows you to match specific values to create an alarm. No longer are you limited to Boolean true or false, or just greater than or less than other values. In fact, you’re not even limited to decimal values as you can use hexadecimal numbers, floating point numbers, or even strings.
In WIN-911 Workspace, you can have an alarm condition when a value is:
· Equal (=) to another [27 = 27]
· Not equal (≠) to another [36 ≠ 48]
· Greater than or equal (≥) to another [37.6 ≥ 24.3]
· Less than or equal (≤) to another [42.5 ≤ 42.5]
· Greater than (>) another [Banana > Apple]
· Less than (<) another [Brussel Sprouts < Candy]
The value types you can use are:
· Integers [27, 64, 42]
· Floating point [18.489, 98.6, 3.141592653589793238]
· Hexadecimal [0xEA, 0x02D7AA, 0xD407]
· Strings [Hello, ON, oFf, pa$$w0rD]
It’s important to remember that if you want to compare to a hexadecimal value, it should be entered in the form of ‘0x’ and then the rest of the number, such as 0x4D. Also, there is no converting an incoming value to hex, so it must come from the OPC server as hex for the match to work. For example, 0x53 will not be equal to 83.
For strings, just enter the text in the input box, they don’t need quotes. In fact, you can match against quotes if you need to do so (“Alert” = “Alert”).