Tuesday, November 24, 2015

Friday, August 28, 2015

PLC Troubleshooting

PLC Troubleshooting - Failure Probability

PLC MTBF does not apply, so much.

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Failure probability is categorized like this (in order of most likely to least likely).

  1. Mechanical
  2. Electro-Mechanical
  3. High Current
  4. Low Current
  5. Solid State

Environment can be an exception to the general rule.
(Relay card most likely, and MTBF is useless unless solid state, as frequency PLC program activates, dictates failure rate as well as the environment does.)

The above probability guide translate to troubleshooting PLCs as ...

  1. Output Cards
  2. Input Cards
  3. Power Supply
  4. Backplane
  5. CPU (Processor Card)

Environment can change basic order above. Examples: In a foundry, the metal dust causes backplane to fail more frequently. Machining industry, penetrating fluid getting into sensors causes input cards to fail more than output cards because sinks more current than designed to. Wire manufacturing a lot of high voltage insulation testing is going on, CPUs fail more often because control voltage for PLC does not have line filter in series with it.

(More PLC Troubleshooting)

Don (Follow me on Industrial Skills Training Blog and on Twitter @IndTraining .) Be sure to to stay on top!

Monday, July 13, 2015

PLC Training Video Series

PLC Training Video Series ...

PLC training videos
PLC Training Videos
PLC Training videos come in many flavors. From just an ad, to introductory to full PLC training video series course. The PLC training video series below is 6 samples that are very popular. The samples in this series have been selected as samples of the various PLC training video types mentioned previously. Enjoy and share your favorite one.

  1. PLC training video ad: PLC Training Org
  2. Introductory PLC training video: What is a PLC
  3. Experience transfer: PLC Training
  4. Simplifying complex concept: PLC Training PAC
  5. PLC training video series on a single topic: PLC Training - Networking
  6. PLC training video series course: PLC Training Video Course

Don (Follow me on Industrial Skills Training Blog and on Twitter @IndTraining .) Be sure to to stay on top!