Operator: __VARINFO

The operator is an extension of the IEC 61131-3 standard.

The operator yields information about a variable. You can save the information as data structure in a variable of data type ‎__SYSTEM.VAR_INFO‎.

Syntax in the declaration

<name of the info variable> : __SYSTEM.VAR_INFO; // Data structure for info variable

Syntax for calls

<name of the info variable> := __VARINFO( <variable name> ); // Call of the operator

Example

FUNCTION_BLOCK FB_Velocity
VAR_INPUT
        rVelocity: REAL := 1.2;
END_VAR
VAR_OUTPUT
END_VAR
VAR
        infoVelocity: __SYSTEM.VAR_INFO; //Info of Velocity
END_VAR

infoVelocity := __VARINFO(rVelocity); // Gets the info of Velocity locally

PROGRAM PLC_PRG
VAR
        iCounter : INT := 0; // Counts the calls
        infoCounter : __SYSTEM.VAR_INFO; //Info of Counter
        arrA : ARRAY [1..2, 1..2, 1..2] OF INT := [0, 1, 2, 3, 4, 5, 6, 7]; // Stores the A data
        infoA : __SYSTEM.VAR_INFO; //Info of A
        fbVel : FB_Velocity;
END_VAR

iCounter := iCounter + 1;
infoCounter := __VARINFO(iCounter);
infoA := __VARINFO(arrA);
fbVel();

The ‎iCounter‎ and ‎arrA‎ variables are recognized in the application code. The variable information is saved in the ‎infoCounter‎ and ‎infoA‎ variables. Moreover, the ‎FB_Velocity‎ function block is instantiated.

Data Type: __SYSTEM.VAR_INFO