Typical Problems a Technician will Encounter with PLCs

If you are a technician you may encounter problems with PLCs at either the software or hardware level. At the software level, you may be required to layout and enter the original ladder logic program. You may be also involved at the startup of a machine when a program has been written for the PLC, and a technician is required to test the program against the machine operation. In other cases, you may be involved in using a program to troubleshoot the system when a fault occurs. Sometimes you will be requested to make changes in the documentation that describes the operation of the system and identifies all the inputs and outputs. In each of these cases, you may need additional information to satisfactorily accomplish these jobs. This additional information may be provided in manufacturers’ manuals, or in short 4 - 5-day training courses that are provided on specific PLCs.

You may also be involved with the hardware modules and I/O devices that are connected to PLCs. In some systems you will be requested to read the specification sheets for the signals that each module sends or receives so that you can select the proper types of electronic devices to interface with the PLC. (continues below)

Sometimes you will be requested to analyze a signal to see that it meets the proper criteria for data transmission. If system component failure occurs, you will be required to use all the knowledge you have about electronics to test the hardware and make decisions. You now have a better idea of how electronics have been blended with the programmable controller to provide industrial automation.