Mitsubishi PLC logic series operation instructions WAND, WOR, WXOR and NEG - Database & Sql Blog Articles

(1) Logic AND Instruction: The WAND(D)/WAND(P) instruction is numbered FNC26. It performs a bitwise AND operation between two source operands and stores the result in the specified destination. This is commonly used for masking or filtering bit patterns.

(2) Logic OR Instruction: The WOR(D)/WOR(P) instruction is numbered FNC27. It executes a bitwise OR operation on two source operands and writes the result to the target component. For example, when X1 is active, (D10) ∨ (D12) → (D14), as shown in Figure 4-48.

(3) Logical XOR Instruction: The WXOR(D)/WXOR(P) instruction is numbered FNC28. It performs a bitwise XOR operation on the source operands, which is useful for toggling bits or detecting differences between two values.

(4) Negation Command: The NEG(D)/NEG(P) instruction is numbered FNC29. It inverts the bits of the value in the specified register and adds 1, effectively converting a positive number into its negative equivalent. The result is stored back into the same register.

The application of these logical instructions is illustrated in Figure 1.

Figure 1: Usage of Logical Operation Instructions

When using logic instructions, consider the following points:

1) For WAND, WOR, and WXOR instructions, both [S1.] and [S2.] can be any data type, while the target operand can be KnY, KnM, KnS, T, C, D, V, or Z.

2) The NEG instruction only has a single operand, which can also be KnY, KnM, KnS, T, C, D, V, or Z.

3) The 16-bit versions of WAND, WOR, and WXOR require 7 program steps, while the 32-bit versions take 13 steps. The NEG instruction uses 3 steps for 16-bit and 5 steps for 32-bit operations.

These instructions are essential in PLC programming for manipulating digital signals and performing complex logical operations efficiently.