You can use this function to transfer the value of a message characteristic that has been defined as a variable from one process instruction to another process instruction. In this way, you ensure that the current value is always passed on to the other process instruction in message characteristics whose values can constantly be changed (for example, by entries).
In this case, the variable value is not displayed as a default value, which means that you cannot change it in the browser-based PI sheet or process manufacturing cockpit .
When defining value assignment using variables, you specify the following information in the process instruction:
The variable to be assigned to the message characteristic
The message characteristic whose value is to be obtained from a variable
To enter this information, you assign the following characteristics to the process instruction in the order specified below:
Characteristic |
Meaning |
Allowed Values |
PPPI_DEFAULT_VARIABLE |
Variable to be assigned to the message characteristic |
Variable name, see Using Variables in Browser-Based PI Sheets and Cockpits
|
PPPI_EXTERNAL_VALUE |
Message characteristic whose value is to be assigned using variable |
Message characteristic |