iFIX ODBC provides communication between relational databases and the iFIX database. The iFIX database can be configured to communicate based on an event, a time, or a combination of both.
iFIX ODBC consists of the:
The SQL task performs the following functions:
- Executes the SQT blocks that trigger.
- Retrieves process data from the SQD blocks and inserts the data into the relational database.
- Selects data from the relational database and writes the data back to the iFIX database.
- Backs up data in the event of a network failure (backup continues until the primary and secondary paths are full).
- Automatically restores data to the relational database once network communications are established.
The SQL Trigger block defines:
- Which SQL commands in the SQL Library Table are used to manipulate data.
- Whether the SQL commands are backed up in the event that the application loses a connection with the server.
- The time or event that triggers the data transfer.
The SQL Data block defines:
- The data that is collected and transferred.
- The direction of the data transfer.
Both database blocks communicate with the SQL task, WSQLODC.EXE. This task runs on a SCADA node and handles communication with the ODBC driver.
If the connection to the relational database is lost, SQL commands and data can be backed up. When the connection is re-established, SQL commands and data are executed in the order in which they were backed up. Refer to the Backing Up and Restoring Data section for a more detailed description of the back-up and restore process.
NOTE: If you copy and paste the SQT and SQD blocks, they will not fire. You must create these blocks in full.
