Custom data quality function support for the PI-OASyS interface

A PI Tag can be configured to retrieve the data from a RealTime database (RTDB) point, or to check the data quality of the point first and then retrieve the data. For a PI Tag that requires data quality checking, the PI-OASyS interface checks to see if the data quality of the point is good. If the data quality is good, the actual value of the point will be sent to the PI Server; otherwise, the bad data quality state name will be sent to the PI Server.

For example, assume that an analog point’s curval value is 105.59, but the point is experiencing an error condition. The [DQCHECK] configuration, meanwhile is set to return the error state of 255.

[DQCHECK]

1=error 1 255

2=fresh 0 288

3=offscan 1 238

In the System Management Tool (SMT), the PI Tag for this analog point will show the bad data quality state name error (255) instead of the value (105.59).

You may still want the PI Tag to show its actual value even the point is in a bad data quality state. For example, if the point is in the manual input state, the flag.fresh for this point will be set to false automatically by the RTDB service. So that when the PI-OASyS interface does the Data Quality (DQ) checking for this point, the bad data quality Stale will be sent to the PI Server. If you want the PI Tag to show the actual value of the point and not the Stale state, the DQ checking can be set to do this.