AH500 Programming Manual Symbol: LDF S ： Specified device Bit ANDF ORF Explanation: 1. The instruction LDF functions to reserve the current contents, and store the falling-edge detection of the contact in the accumulative register. 2. The instruction ANDF is used to connect the falling-edge detection of the contact in series. 3. The instruction ORP is used to connect the falling-edge detection of the contact in parallel. 4. Only when LDF/ANDF/ORF is scanned can the state of the device be gotten, and not until LDF/ANDF/ORF is scanned next time can whether the state of the device changes be judged. 5. Please use the instructions NED, ANED, and ONED in the subroutine. Example: 1.
The falling-edge detection of X0.0 starts, the falling-edge detection of X0.1 is connected in series, the falling-edge detection of X0.2 is connected in parallel, and the coil Y0.0 is driven. 2. When both X0.0 and X0.1 are switched from OFF to ON, or when X0.2 is switched from OFF to ON, Y0.0 is ON for a scan cycle. 5-12 Instruction code Operand Function LDF/ANDF/ORF S 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 L PR S ● ● ● ● ● ● ● ● ● ● ● ●