Variable Read Rules

Table 1 lists the rules for reading manually specified or imported variables when different variable read modes and sharing modes are selected.

**Table 1** Variable read rules
Variable Read Mode	Variable Sharing Mode	Description	Example
Sequential	Case	Each concurrency reads a variable value in sequence.	For example, for a task with a concurrency of 10, each concurrency reads a variable value in sequence.
Sequential	Concurrency	Each concurrency copies a variable with the same name for use. Different concurrent requests read the variable values in sequence and do not affect each other.	For example, for a task with a concurrency of 10, each concurrency reads the copied variable values in sequence.
Random	Case	Each concurrency randomly reads a variable value.	For example, for a task with a concurrency of 10, each concurrency randomly reads a variable value.
Random	Concurrency	Each concurrency copies a variable with the same name for use. Different concurrencies read the variable values randomly and do not affect each other.	For example, for a task with a concurrency of 10, each concurrency reads the copied variable values randomly.

Assume that the number variable has three values: 1, 2, and 3, and there are two concurrencies: A and B.

In sequential mode:
Case mode: A reads 1 of number, and B reads 2 of number. The process goes on cyclically.

Concurrency mode: A reads a copied variable number starting from 1. Concurrency mode: B also reads a copied variable number starting from 1.
In random mode:
The method of reading variable values is the same as that in sequential mode, regardless whether the Case or Concurrency sharing mode is used.