MEQ (Mask Equal To) Ladder Logic Instruction

The Mask Equal To instruction is a ladder logic rung input instruction that compares a source value to a compare value through a mask. If the adjusted source and compare values are equal the logic to the right of the instruction, or rung-condition-out, is enabled and disabled if otherwise. The Source value, Mask value and Compare value can be constants, tags or any combination.

Constant or immediate values always default to decimal display. To display the value in a different radix precede the value with one of the following prefixes.

Prefix              Description                 Example

  •             16#                  hexadecimal                16#FFF0
  •             8#                    Octal                                8#16
  •             2#                    Binary                             2#01010101

List of possible arguments

The SOURCE VALUEMASK VALUE, and COMPARE VALUE can be any combination of the following data types.

  • SINT              
  • INT
  • DINT
  • REAL

 Note: Negative numbers are valid.

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