RLO

RLO Result of Logic Operation

The RLO bit saves the result of a string of logic operations or compare instructions.

The RLO bit is bit 1 of the status word.

The first instruction in a network checks the signal state of a contact. If the check condition is satisfied, the RLO is set to 1. The second instruction also checks the signal state of the contact. The result of this check is now combined with the value stored in the RLO bit using the rules of Boolean algebra and the result saved in the RLO bit. This string of logic operations is completed by an assignment or a conditional jump which is executed depending on the value in the RLO bit.