Programmable Logic Controller (PLC) Wiring & Troubleshooting II

Overview: At the completion of this course, the participants will have the ability to “talk through” and troubleshoot the PLC’s ladder logic using the Logix5000 software in order to locate a “real,” faulty input or output device, replace it, and get the process back up and running. It’s all about troubleshooting! The suggested prerequisite for this course is the “PLC Wiring & Troubleshooting I” course or prior experience.

The participant will begin their training by wiring the actual input and output (I/O) devices such as photo-electric sensors, inductive proximity and selector switches, pushbuttons, and outputs such as contactors, indicator lamps, etc., to the PLC’s input/output module. The participants actually wire their own PLC trainer!

  • A review of the PLC’s instruction-set including “real” and “simulated” I/O, troubleshooting tools that “toggle” and “force” I/O, Timer (TON, TOF, RTO) and Counter (CTU, CTD) circuits, special functions such as One-Shot (ONS), First Scan (S:FS), Set Bit if Zero/Negative (S:Z, S:N), Comparison instructions such as EQU, NEQ, GRT, LES, GEQ, LEQ, LIM, etc., Math instructions including ADD, SUB, MUL, and DIV. These instructions were initially covered in the “PLC Wiring & Troubleshooting I” course.
  • Ladder logic utilizing Jump (JMP) and Master Control Reset (MCR) instructions will be introduced along with the Jump to Subroutine (JSR) instruction.
  • To effectively troubleshoot a Logix5000 PLC-based system, one must know how the PLC’s Memory Structure is allocated throughout the ladder logic program. Therefore, one and two dimension arrays will be covered
  • Examples of Sequencer circuits involving the Sequencer’s various tables such as Array, Mask, and Output tables will be covered in detail.
  • Understanding how Indirect Addressing and its associated memory arrays are applied in a ladder logic program is critical in troubleshooting a PLC-based system.
  • One of the most powerful tools found in the Logix5000 software is the “Add-On Instruction.” In order to troubleshoot these instructions, one must know how to interpret their “Definition Table,” which consists of various “tagged” parameters and the ladder logic used to develop the Add-On Instruction. Therefore, each participant will create and troubleshoot several Add-On Instructions.

NOTE: Numerous hands-on labs utilizing troubleshooting skills are included in all of the above subject matter in order to reinforce the lecture material.