# Properties (Variables)

[Source]
Select the source for reading and writing data as either internal or external device.

Note:

- This property is not available for local variables.
- The source of local variables is fixed to [Internal].

[Device Address]
This is only available when the [Source] is set to external device. Assign an external device address.

Note: This property is not available for local variables.

[Scan Rate]
This is only available when the [Source] is set to external device. Select the scan rate for getting device address data.
Important: Scan Rate is NOT available for drivers with addresses that are managed in the memory of the display unit, like Modbus SIO Slave, Modbus TCP Slave, Memory Link SIO and Memory Link Ethernet. Even if you configure Scan Rate settings, they are NOT used by these drivers. Note: For information about scan rates, refer to the following. Setting the Interval for Reading External Variable Values (Scan Rate)

[Initial Value]
Set the initial value for the internal variable.

[Value]
This is only available when the [Source] is set to [Internal]. Select the source property to be referred for the value. At runtime, the value for the variable that use the source property can be changed dynamically by changing the values of the source property.
Data Binding Support: To use as a Binding Source, refer to the following. '(variable name).Value' When used as a Binding Target, the Binding Sources that can be associated are as follows. [ Alarm] [ Variable] [ Target] [ Equipment] [ Recipe] For more information of Data Binding concept, refer to the following. Data Binding

[Input Range]
Select this check box to limit the values range written to the variable from the display unit. Data write operations by the external device are not limited by this function.

[Minimum] / [Maximum]
[Minimum] / [Maximum] defines the range of values that you can write to the variable from the display unit.
Note: For information about variable value ranges, refer to the following. Data Types

[Variable Length]
This is only available when the [Source] is set to [Internal]. Select to make the number of bytes that can be stored variable.

[Number of Bytes]
This is only available when the [Data Type] is set to [STRING] or [WSTRING]. When the [Data Type] is set to [STRING], select the string encoding. The number of characters the string variable supports is defined by the [Number of Bytes] and the [String Encode] Setting Value Range: 1 - 512

[String Encode]
This is only available when the [Source] is set to external device. When the [Data Type] is set to [STRING], select the string encoding.
Note: You can also configure string encoding in equipment properties. The variable property setting takes priority over the equipment property. In the variable's [String Encode] property, select [Equipment Setting Type] to apply the equipment's string encode setting. For a selected variable or driver, if you use a text whose character code cannot be converted by the [String Encode], then the end of the string is recognized by character code. When the [Data Type] is set to [STRING], String encoding is fixed as UTF16.

[Retentive]
Retains internal variable value while display unit is shut down.
Note: The number of variables you can set [Retentive] depends on the available space in backup memory (SRAM). To check the data area required to retain variable values, see the following. Calculating the Size of Data to Save Regardless of the [Retentive] setting, variable values are reset to their [Initial Value] every time the project is transferred. You cannot enable [Retentive] in external variables. This property is not available for local variables.

[Data Type]
Select the type of data to be stored in the variable.
Note: For information on data types, refer to the following. Data Types

[Data Sharing]
Select whether to share the variable with the OPC UA Server. This property is available when [OPC UA Server] is enabled. [Target01] Properties window > [Detail] tab > [Data Access] tab > [OPC UA Server] Properties (Target01) -[None]: The variable cannot be viewed or edited by clients. -[Read Only]: Clients on the network can view the variable value. -[Read Write]: Clients on the network can view and edit the variable value. Note: This property is not available for local variables.

[Comments]
Enter comments about the variable.