You define variables in process data requests and calculation formulas to transfer the value of a message characteristic to a succeeding process instruction.

Here, you can use the variable for the following, for example:

• To define default values and input validations in process data requests

• To assign values to message characteristics in hidden data requests

• To define calculation formulas in process data calculation formulas

• To define export and changing parameters in dynamic function calls

You can define a variable for every message characteristic of a process instruction. The data type of the variable is identical to that of the message characteristic (for example, CHAR or NUM).

Depending on how you define the variable, it is valid:

• In the PI sheet in which it has been defined

• For the entire process order

To define a variable, you assign one of the following characteristics immediately before the message characteristic in the process instruction:

In general, you can choose any name for a variable. To avoid conflicts with other functions, do not use:

• The variable name X

• Blanks and arithmetic operators as part of the variable name

• The following character strings at the end of the variable name:

• _<number>, for example, _1, _2
• _COUNT
• _SUM