Chapter 5 Basic Instructions 5-3 Page Instruction code Function Operand Step number FB NP _ The circuit is rising edge-triggered. X, Y, M, SM, S, T, C, HC, D, L, and PR 1-2 5-24 FB PN _ The circuit is falling edge-triggered. X, Y, M, SM, S, T, C, HC, D, L, and PR 1-2 5-25 PSTOP Stopping executing the program in the PLC – 1 5-26