Programming an XOR Instruction in RSLogix 500

Introduction

The XOR, also known as Exclusive OR is a word-level instruction. It’s an advanced instruction that can be used in programs where it is important to indicate where an input is in the wrong position.

Programming an XOR Instruction in RSLogix 500

Here’s a real-world scenario of an XOR instruction:

• A Micrologix 1400 Allen Bradley PLC is used to control a process.
• A parts QC machine.
• The part moves in the QC machine and reflexive sensors are used to verify the part is shaped properly.
• An operator presses a pushbutton button or a part in place sensor is activated.

Outcome:

• If all the inputs are in the correct position, the part moves on.
• If any of the inputs are in the wrong condition, the part is rejected using a compare instruction that compares the destination word of the XOR instruction to zero.

Data Types Allowed for XOR

The XOR instruction will work with the following data types within the RSLogix 500 and RSLogix 5000 environment:

• In RSLogix 500 the XOR instruction operates at the word level.
• In RSLogix 5000 the XOR instucion can work many different data types but most commonly used with INTs and DINTs.
  

Important XORs

• XOR – The XOR instruction is located in the Move/Logix bin on RSLogix 500