Value

Item value

Description

Value indicates the value that was last obtained from the OPC server for the item defined by the ItemID property. The data type of the value is given by the DataType property.

The value returned from the server may be different from the value of the device to which the ItemID refers, if the DeadbandPercent for the daitem object's parent group is not zero. The value is also updated only periodically, based on the parent group's Active and UpdateRate properties.

You determine the validity of Value by checking the Quality property for the item.

Value is updated when you perform an asynchronous or synchronous read operation or when a subscription callback occurs.

Characteristics

Access

Read-only

Applies to

daitem

Data type

Any MATLAB® data type

Values

The default value is an empty matrix ([]).

Was this topic helpful?