Data type attribute

The data type (pointtype) attribute specifies what type of data is stored in the PI point.

Typically, OPC item data types do not need to match PI point data types exactly, but the data types must be compatible. For example, integer values from a device can be sent to floating-point or digital PI points. Similarly, a floating-point value from the device can be sent to integer or digital PI points, although the values might be truncated.

PI Interface for OPC DA supports all PI point types except BLOB.

Note: Some OPC servers lack support for the full range of PI point types. To determine which PI point types are supported by your OPC server, refer to the vendor-supplied documentation.

If the point type defined in Data Archive does not match the required data type defined in the OPC server, the interface attempts to translate the data. To determine whether the point can be read as the required type, use PI OPC Client Tool to try to read the point directly from the OPC server. For more information on data type compatibility, see Data type compatibility.