What is PLC Commissioning?
PLC Commissioning is a series of careful examinations done in a PLC control system to ensure that the controller, program, input and output devices, and associated wiring conform to the specifications of the design.
Before you start PLC commissioning, it is important that you eliminate the possible hazards in your workspace first.
This means that actuators, especially ones that produce powerful movements such as motors or valves must be disconnected from the programmable logic controller.
With that out of the way, here are the steps to get you started with PLC Commissioning.
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PLC Comissioning is a progression of cautious assessments done in a PLC control framework to guarantee that the regulator, program, information and result gadgets, and related wiring adjust to the determinations of the plan.
Before you start PLC appointing, you must first dispense with the potential risks in your work area.
This implies that actuators, particularly ones that produce strong developments, for example, engines or valves should be detached from the programmable rationale regulator.
Steps in PLC Commissioning
1. Cable connections must meet standards
All cable connections between the PLC, the input devices, the power supply, the output devices, and the programming device must be checked thoroughly as they are the media that the PLC uses to communicate between each of the devices.
All cables must meet the required specifications according to the standards, it should even meet the local standards set for the specific hardware.
2. Check the power supply
The power supply of the PLC must match the voltage setting of the PLC.
The voltage setting of the power supply must also conform to the voltage ratings of the input and output devices, otherwise, one of the two must be replaced by another device.
3. Check indicator lights of the PLC
The indicator lights on the PLC should determine if the PLC will work properly.
If the power is properly applied, the power indicator of the PLC should turn on. Fault indicators are usually installed on PLCs, so ensure that the fault light is not turned on at this point.
4. Put PLC in a test mode.
The PLC must be put in a mode that prevents it from sending an output voltage or current to the output devices.
This can either be called “Disable” or “Continuous test” mode depending on the PLC manufacturer.
In this mode of operation, the outputs will be de-energized, so you are assured of your safety when testing.
5. Check protective devices
In this step, you must ensure that the protective devices of the PLC are set to their proper trip settings.
6. Check emergency stop buttons
The emergency stop buttons, usually normally closed push buttons, must be checked thoroughly because these buttons are the ones that will stop ALL PLC operations in an emergency event.
7. Check connection points of input and output devices
In this step, the connection points of all input and output devices must be double-checked.
Make sure that each device is connected to the proper address according to the program present in the PLC memory.
If you fail to do this step, you may encounter issues such as the output being turned on at inappropriate times (usually because of the wrong sensor being activated).
So, pay extra attention to this step.
8. Test the software
After all of the previous steps have been performed, it is now time to load the program into the PLC and start testing the software.
Testing the software is relatively easy as most PLCs contain software-checking programs already.
Even though this step checks the program for incorrect device addresses, it is always important to do the preceding step (Checking connection) in order to save time.
The PLC provides a printout of the input and output points that were used, along with the counter presets, timer settings, with the errors that it has encountered.
If you already did a great job in the preceding steps, doing this only serves as a “proofread” for all the things that you have performed.
Conclusion
PLC Commissioning is a process that involves doing each and every detail of setting up a PLC system with a safety precaution in mind. Also, it is a good investment of your time because it lessens the possibility of failures in the future.
