Declaration of Variables

At a Glance

All of the variables used in the different sections of the program must be declared.

Undeclared variables cannot be used in the program.

NOTE: For more information, refer to chapter Data Editor.

Procedure for Declaring Variables

The table below shows the procedure for declaring application variables:

Step	Action
1	In Project Browser / Variables & FB instances, double-click on Elementary Variables
2	In the Data Editor window, select the box in the Name column and enter a name for your first variable.
3	Now select a Type for this variable.
4	When all your variables are declared, you can close the window.

Variables Used for the Application

The following table shows the details of the variables used in the application and declared in the project associated with the PLC X:

Variable	Type	Definition
Adr_Char	STRING	Master PLC serial port address.
Adr_modbus	STRING	Modbus Slave PLC serial channel address (channel 0 of BMX NOM 0200 module).
AnsString1	STRING	First modem answer character string.
AnsString2	STRING	Second modem answer character string.
AnsString3	STRING	Third modem answer character string.
Error	INT	Function error code.
Function_Step	INT	Function step.
MngtInput	ARRAY[0..3] of INT	Array of the communication parameters for the INPUT_CHAR block.
MngtPrint	ARRAY[0..3] of INT	Array of the communication parameters for the PRINT_CHAR block.
MngtWrite	ARRAY[0..3] of INT	Array of the communication parameters for the WRITE_VAR block.
nb_charac_to_receive_connect	INT	Number of character to receive: modem connexion
nb_charac_to_receive_ok	INT	Number of character to receive: modem confirmation message
ReqString	STRING	Modem answer.
Start	EBOOL	Starting mode (signal coming from channel 0 of the BMX DDI 1602 module).
Serial_Port	T_COM_MB_BMX	Serial port I/O object
Test_inc	INT	Incrementation value

The following screen shows the application variables created using the data editor:

Declaring an Array Type

Before declaring an Array type, click on Tools/Project Settings/Variables then check "Directly represented array variables" and "Allow dynamic arrays"

The following table shows how to declare an Array type:

Step	Action
1	In the ProjectBbrowser, click on Variables & FB instances.
2	Click in the Name column and enter a name for the variable.
3	Double-click in the Type column and then click on the button. The Variable Type Selection window opens:
4	Choose the desired variable type (for example, click on <EDT> and select INT), then click into the Array checkbox.
5	Modify the intervalle, then confirm with OK.

Declaration of I/O Objects

For declaring I/O Derived Variables, open the Variable Type Selection window as described in the above procedure and click on <Catalog> to access the <IODDT> type variables (select T COM MB BMX for example), then confirm with OK.