The SQL Data block identifies the blocks that transfer to or receive data from your relational database. The block, however, does not monitor a block's status or mode. If a block is off scan, when the upstream SQL Trigger block starts, the SQL task substitutes a null value for the off-scan block's current value. If the target column in the relational database cannot accept a null value, the INSERT or UPDATE fails and the SQL Trigger block generates an alarm.
