Omron NX-SIH400, User Manual

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*3. If you use the WORD data type for a global variable, you must define an exposed variable or use a con-
stant.
*4. If you use the SAFEWORD, TIME, or SAFETIME data type for a global variable, you must set a constant.
Bit String Data Format
This section describes the data format for bit string data.
"Bit 0" is the least significant bit of a bit string variable.
Bit values are expressed as 1 or 0.
0
Bit 0 Bit 7
BYTE#16#3B 0 1 1 1 0 1 1
6-2-6
Variable Attributes Other Than Data Type
This section describes the variable attributes other than the Data Type.
Variable Name Attribute
The variable name is used to identify the variable.
Each variable in a POU must have a unique name. However, you can declare local variables with the
same variable name in different POUs. These are treated as two separate variables.
You cannot declare an internal variable with the same variable name as a global variable.
Initial Value Attribute
The variable is set to the initial value in the following situations.
• When the power supply is turned ON
• When the mode is changed to RUN mode
• When the mode is changed to DEBUG mode (STOPPED)
l
Types of Variables That Can Have Initial Values
You can set initial values for only some types of variables. A list is provided below.
Variables Initial Value Settings
Global variables Yes (required)
Internal variables
Input variables
Output variables
External variables
Not possible.
You must set initial values for all variables that allow them.
6 Programming
6 - 16
NX-series Safety Control Unit User's Manual (Z930)