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THE PLC LAWS


 

Dikutip dari http://migas-indonesia.net

PLC LAW #1 – DON’T OVERCOMPLICATE THE SIMPLE.

PLC LAW #2 – MAKE SURE YOU PLUG THE CABLE IN BEFORE YOU TRY TO FIGURE OUT WHY YOU CAN’T GO ONLINE.

PLC LAW #3 DURING STARTUP, ALWAYS VERIFY I/O BEFORE TESTING THE PROGRAM

PLC LAW #4 WHEN CONNECTING YOUR LAPTOP TO THE PLC, DON’T TIGHTEN THE SCREWS ON THE SERIAL CABLE AT THE LAPTOP SIDE.

PLC LAW #5 Read the manual BEFORE trying to install/commission an unfamiliar piece of hardware.

PLC LAW #6 Allways have all possible backup files (plus read from PLC etc.) before starting any changes.

PLC LAW #7 Allways double check you have the right cables for your CPU type and backup install software with you before you step on the plane.

PLC LAW #7.1 When working in a LAN or WAN environment always triple check processor ID’s before erasing and downloading new code.

PLC LAW #8 – Each vendor has their own programming software, so plan accordingly.

PLC LAW #8.1 – Some vendors software may not play well with others… See RSLinx…

PLC LAW #8.2 – Order the correct software from your vendor instead of asking for it on MrPLC

PLC Law #9 – When powering up a PLC the first time, make sure that the power supply voltage switch is set to the right voltage.

PLC LAW #10 Try to stage and test as much as possible before making big changes.

PLC LAW #11 Spares should not sit of the shelf. They should be used for training and tesing.

PLC Law #11.1 – THERE MUST BE SPARES FOR CRITICAL PARTS!

PLC LAW #12 Programs should have many rungs of diagnostic ladder that can be enabled or disabled quickly. This includes timers for timeouts. These determine when input devices are not working properly. FIFOs are good for logging real time events. Counters that count errors are handy too.

PLC LAW #13 The best PLC programs are able to recover from error conditions quickly. This can make a big difference to overall production.

PLC LAW # 14 ALL PROGRAMS SHOULD BE WELL DOCUMENTED

PLC LAW #15 MAKE SURE YOU ACTUALLY UNDERSTAND THE QUESTION IN THE DIALOG BOX BEFORE HITTING “OK”

PLC Law #16: Remember to put a paper copy of the latest PLC ladder in the electrical cabinet.

PLC Law #17: When all else fails, add a TIMER, and a one-shot too just in case.

PLC Law #18: When a non PLCite tells you that a machine is not working because of “programming errors”, ask for proof before changing your masterpiece.

PLC Law #18.1: When the machine is down, the blame will be assigned to whichever component the person assigning the blame understands the least.

PLC Law #18.2: American Money says “In God we Trust” – with PLC’s all others bring relevant data.

PLC Law #19: Make sure that your PLC and or process will run without the HMI (if using one).

PLC LAW # 20” A good programmer will never believe the guy who says nothing has changed since it worked.

PLC LAW #21: Make sure that the default settings doesn’t cause the PLC to fail from starting to operate properly after a blackout.

PLC LAW #22 PLC Logic can not change by itself.

PLC LAW #23 – NEVER UNDER ANY CIRCUMSTANCES LEAVE FORCES IN A PROCESSOR. THEY SHOULD ONLY BE USED FOR TEMPORARY TESTING WHICH MEANS REMOVE THEM BEFORE GOING OFFLINE

PLC LAW #24 – Always be sure that the rung / ladder / block you are troubleshooting is being scanned BEFORE you make major changes or spend 6 hours troubleshooting it!!!

PLC LAW #25 When teaching points on a robot, or programming a vision system that interfaces with a machine designed with a dial indexer, make sure your index table is on station.

Artikel tentang PLC dan control yang lain bisa di lihat di:

http://migas-indonesia.net/

 


1 Comment

  1. Especially law 23, that is why there is a force light on PLC processor, it is very important you know if someone left forces in the PLC. Great job on these rules. If they follow them, they will save thousands to millions, not to mention maybe save someone’s health.

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