3 Basic Instructions Program Example: Ladder diagram: Instruction code: Operation: X0 X1 Y1 AND X1 Series connecting A contact of X1 OUT Y1 Driving Y1 coil Remarks: 1. See the specification of each model for the range of operands. 2. If the status of a designated rising-edge is On before the PLC is powered, the contact of the rising-edge will be TRUE after PLC is powered. Explanations: The method of using LDF is the same as using LD, but the actions of the two instructions differ. LDF saves the current content and store the detected status of falling-edge to the accumulative register. Program Example: Ladder diagram: Instruction code: Operation:
AND X1 Series connecting A contact of X1 Y1 OUT Y1 Driving Y1 coil Explanations: ANDP instruction is used in the series connection of the contacts’ rising-edge detection. Program Example: Ladder diagram: Instruction code: Operation:
X1 X0 Y1 LD X0 Loading in A contact of X0 OUT Y1 Driving Y1 coil DVP-PLC Application Manual 3-13 LDP X0 Starting X0 rising-edge detection Mnemonic Function Program steps Controllers LDF Falling-edge detection operation 1 ES EX SS SA SX SC EH 2 SV EH 3 SV 2 X0 ~ X377 Y0 ~ Y377 M0 ~ M4095 S0 ~ S1023 T0 ~ T255 C0 ~ C255 D0 ~ D9999 Operand - X 0 X LDF X0 Starting X0 falling-edge detection Mnemonic Function Program steps Controllers ES EX SS SA SX SC EH2 SV EH3 SV2 ANDP Rising-edge series connection 1 X0 ~ X377 Y0 ~ Y377 M0 ~ M4095 S0 ~ S1023 T0 ~ T255 C0 ~ C255 D0 ~ D9999 Operand - ES EX SS SA SX SC E H 2 SV EH 3 SV2 ANDP X1 X1 rising-edge detection in series connection