5 Categories & Use of Application Instructions Continuous execution instruction and pulse execution instruction Continuous execution and pulse execution are the two types of execution for an application instruction. Due to that the execution time required will be shorter when the instruction is not executer, the pulse execution instructions are used more to shorten the scan period. Instructions marked with a “P" following the mnemonic are pulse execution instruction. Some instructions are mostly used as pulse execution type, e.g. INC, DEC, the kind of displacement instructions.
Pulse execution instruction When X0 goes from Off to On, MOVP instruction will be X0 executed once and the instruction will not be executed again in the scan period. Continuous execution instruction X1 In every scan period when X1 = On, MOV instruction will be executed once. In the two figures, when X0, X1 = Off, the instruction will not be executed, and the content in operand D will remain unchanged. Designation of operands 1. Bit devices X, Y, M, and S can be combined into word device, storing values and data for operaions in the form of KnX, KnY, KnM and KnS in an application instruction. 2. Data register D, timer T, counter C and index register E, F are designated by general operands.
3. A data register is usually in 16 bits, i.e. of the length of 1 register D. A designated 32-bit data register refers to 2 consecutive register Ds. 4. If an operand of a 32-bit instruction designates D0, the 32-bit data register composed of (D1, D0) will be occupied. D1 is the higher 16 bits; D0 is the lower 16 bits. The same rule also apply to timer T, 16-bit timers and C0 ~ C199. 5. When the 32-bit counters C200 ~ C255 are used as data registers, they can only be designataed by the operands of 32-bit instructions. Format of operand 1. X, Y, M, and S can only On/Off a single point and are defined as bit devices. 2.
16-bit (or 32-bit) devices T, C, D, and registers E, F are defined as word devices. 3. You can place Kn (n = 1 refers to 4 bits. For 16-bit instruction, n = K1 ~ K4; for 32-bit instruction, n = K1 ~ K8) before bit devices X, Y, M and S to make it a word device for performing word-device operations. For example, K1M0 refers to 8 bits, M0 ~ M7. X0 When X0 = On, the contents in M0 ~ M7 will be moved to bit0 ~ 7 in D10 and bit8 ~ 15 will be set to “0”. DVP-PLC Application Manual 5-8 MOVP D10 D12 MOV D10 D12 MOV K2M0 D10