Time stamp options
- Last UpdatedMay 22, 2025
- 2 minute read
PI Interface for OPC DA can use the time stamps provided by the OPC server or create its own time stamps at the time that the data is received. Windows type time stamps are defined as Coordinated Universal Time (UTC), and items with VT_* variant values are interpreted as local time without daylight savings time adjustments.
If the OPC server provides time stamps, you can use PI ICU to configure the behavior of the interface as follows:
|
Option |
Description |
Timestamp Offset Applied |
|---|---|---|
|
Interface Provides Time stamp (/ts=N) |
(Default) The interface time stamps each value as it is received. Choose this option if the OPC server cannot provide accurate time stamps or you do not want to use the time stamps returned by the OPC server. |
Difference between Data Archive node and interface node. |
|
OPC Server Provides Time stamp (/ts=Y) |
The interface uses the UTC time stamp provided by the OPC server. |
Difference between Data Archive node and OPC server node. |
|
Time stamp for Advise Tags Only (/TS=A) |
For polled reads, some OPC servers return the time that the value last changed rather than the time of the read. This option configures the interface to use the advise time stamps but provides time stamps for the polled values. For more details about advise and polled points, see Input points. |
For advise data, difference between Data Archive node and OPC server node. For all other data, difference between Data Archive node and interface node. |
|
OPC Server Provides Timestamp, no Offset (/ts=U) |
The interface uses the UTC timestamp provided by the OPC server and does not apply any offset to the time stamps. Caution: Use this setting with extreme caution, as data loss occurs if the OPC server sends a value with a timestamp that is 10 minutes or more later than the current time of Data Archive. |
None. |
For details about reading and writing time stamps from a PI point when the time stamp is the value of the point, see Time stamp adjustments.