Chapter 6 Applied Instructions 5. When M3 is ON, whether the socket has been connected is checked. If the socket has been connected, the connection will be closed. If the socket has not been connected, the instruction is not executed. After the connection is closed, M2 and M3 will be switched OFF. Additional remark: 1. If S 1 , S 2 , or S 3 exceeds the range, the instruction is not executed, SM0 is ON, and the error code in SR0 is 16#2003. 6-512