Chapter 5 Basic Instructions Symbol NED S 1 ： Specified device ANED S 2 ： For internal use 5_ ONED Q ： Output the state of the operation result Explanation 1. NED/ANED/ONED correspond to LDF/ANDF/ORF. The only difference between NED/ANED/ONED and LDF/ANDF/ORF is that you must specify the bit device S 2 in which to store the previous state of the contact when NED/ANED/ONED is executed. Do not use the device S 2 repeatedly in the program. Otherwise, the wrong execution result appears. 2. ANED connects the falling-edge detection of the contact in series. 3. ONED connects the falling-edge detection of the contact in parallel. 4. The system must scan NED/ANED/ONED to get the state of the device.
Changes to the device state are not detected until NED/ANED/ONED is scanned the next time 5. You can use NED/ANED/ONED only in function blocks. 6. The state of the operation result is automatically output after the instruction is executed. You do not need to use input device for this. 5-13 Instruction code Operand Function NED/ANED/ONED S1，S2 Starting the falling-edge detection/Connecting the falling-edge detection in series/Connecting the falling-edge detection in parallel Device DX DY X Y M SM S T C HC D S1 S2 BOOL WORD DWORD LWORD UINT INT DINT LINT REAL LREAL TMR CNT STRING Data type S1 S2