Reading values, the OPC Server sends OPC Client application information on the value, quality, and time stamp of a tag item.
The tag's time stamp will be set to the PC time when the tag value was read from the PLC. Instead of using the PC time for the time stamp, the time stamp can be specified by a DATE_AND_TIME variable in the PLC program. If you enter the address of a PLC's DATE_AND_TIME variable, the OPC Server will read the time stamp value from the PLC.
The following diagram illustrates this process.
The following picture shows the use of a time stamp in an FPWIN Pro project, FP OPC Server and OPC client application.
Please find example projects for the FP OPC Server and FPWIN Pro in your software installation directory.