Jetter AG
Programming | 8
JCM-631 User Manual
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8.2.4 Memory for volatile application program variables
Volatile variables are used to store data which need not be maintained when the
JCM-631 is de-energized.
Properties
■
Global variables which are not assigned to permanent addresses (not %VL or
%RL)
■
Local variables
■
Variables are stored in a compact manner, according to the size of their type
■
Variables are initialized with value 0 when they are created.
Type of access
■
By JetSym
■
From within the application program
JetSym
STX program
In the following program, a global volatile variable is incremented by 1 every 2
seconds.
Var
Count: Int;
//volatile, since not localized
End_Var
;
Task
Inkrement
Autorun
Loop
Inc(Count);
Delay(
T#2s
);
End_Loop
;
End_Task
;
Setup pane
The JetSym setup pane shows the content of the variable:
Number
Description
Function
1
Present content of the
variable
The content of the variable is incremented
by 1 every 2 seconds
8.2.5 Memory for non-volatile application program registers
Non-volatile registers let you store data which must be saved when the controller
is de-energized.
Properties
■
Global variables with dedicated addresses (%VL)
■
Register variables always occupy 4 bytes.
■
Register variables are not initialized by the operating system.
■
Number of register variables: 30,000
■
Register numbers: 1,000,000 ... 1,029,999
Type of access
■
By JetSym
■
By browser (via HTTP server)
■
From HMIs
■
From the application program
■
From other controllers
