Comparator Instructions

Equal Instruction

You can use the "Equal" instruction to determine if a first comparison value (<Operand1>) is equal to a second comparison value (<Operand2>).
If the condition of the comparison is fulfilled, the instruction returns the result of logic operation (RLO) "1". If the comparison condition is not fulfilled, the instruction returns RLO "0". The RLO of the instruction is logically combined with the RLO of the entire rung as follows:

• By AND, when the comparison instruction is connected in series.
  
• By OR, when the comparison instruction is connected in parallel.                                                                                                                                                                          

 Not equal Instruction

You can use the "Not equal" instruction to determine if a first comparison value (<Operand1>) is not equal to a second comparison value (<Operand2>).
If the condition of the comparison is fulfilled, the instruction returns the result of logic operation (RLO) "1". If the comparison condition is not fulfilled, the instruction returns RLO "0". The RLO of the instruction is logically combined with the RLO of the entire rung as follows:

• By AND, when the comparison instruction is connected in series.
  
• By OR, when the comparison instruction is connected in parallel.
  

Greater or equal Instruction

You can use the "Greater or equal" instruction to determine if a first comparison value (<Operand1>) is greater than or equal to a second comparison value (<Operand2>). Both values to be compared must be of the same data type.
If the condition of the comparison is fulfilled, the instruction returns the result of logic operation (RLO) "1". If the comparison condition is not fulfilled, the instruction returns RLO "0". The RLO of the instruction is logically combined with the RLO of the entire rung as follows:

• By AND, when the comparison instruction is connected in series.
  
• By OR, when the comparison instruction is connected in parallel

Less or equal Instruction

You can use the "Less or equal" instruction to determine if a first comparison value (<Operand1>) is less than or equal to a second comparison value (<Operand2>). Both values to be compared must be of the same data type.
If the condition of the comparison is fulfilled, the instruction returns the result of logic operation (RLO) "1". If the comparison condition is not fulfilled, the instruction returns RLO "0". The RLO of the instruction is logically combined with the RLO of the entire rung as follows:

• By AND, when the comparison instruction is connected in series.
  
• By OR, when the comparison instruction is connected in parallel.
  

Less than Instruction

You can use the "Less than" instruction to determine if a first comparison value (<Operand1>) is less than a second comparison value (<Operand2>). Both values to be compared must be of the same data type.
If the condition of the comparison is fulfilled, the instruction returns the result of logic operation (RLO) "1". If the comparison condition is not fulfilled, the instruction returns RLO "0". The RLO of the instruction is logically combined with the RLO of the entire rung as follows:

• By AND, when the comparison instruction is connected in series.
  
• By OR, when the comparison instruction is connected in parallel.

Comparator Instruction in TIA Portal