Upon the occurrence of an event at the REQ input, an instance of this FB type sets the OUT value to the result of replacing the bytes in positions {P..P+L-1} of IN1 with the value of IN2 , and then issues an event at the CNF output.

• Following the IEC 61131-3 convention, the index of the leftmost byte position is 1.
• If  P = 0, the result is the same as if  P = 1.
• If  L = 0, the result is the same as inserting IN2 before byte position P of IN1.
• If  P > N, where N is the number of bytes in IN1, the result is the same as appending the value of IN2 to the value of IN1.
• If  P+L > N, where N is the number of bytes in IN1, the result is the same as appending the value of IN2 to the first P-1 bytes of IN1.