Upon the occurrence of an event at the REQ input, an instance of this FB type sets the OUT value to the position of the first character of the first occurrence of the value of the IN2 input in the IN1 input at or after character position P and issues an event at the CNF output.

• Following the IEC 61131-3 convention, the index of the leftmost character position is 1.
• OUT = 0 indicates that there is no occurrence of IN2 in IN1 beginning at or after P.