I’m a field service engineer for food packaging machines and not an automation specialist, on the other hand can provide you with few hints.
For many automation systems to work, you need to first have a very clear and detailed mechanical plan effortlessly details finalized. Whenever you accomplish that, you should specify the motions involved, e.g.: linear or rotary. This enables you to know the number and kinds of motors and actuators you need(servo, ac single phase, ac 3 phase, pneumatic actuator).
Per motors you might need relay contactors (for single speed discrete/on-off type motors like blower fans and liquid pumps), VFD for speed controllable ac 3-phase motors(a lot more like conveyors, liquid tank level control pumps or rollers).Servo motors need Servo drivers to control their precise movement.
These are generally your output devices, you will want your input devices being set out. This could be level sensors, flow sensors, proximity switches and also other devices as required. The reason i’m stating out this routine is usually to let you define the specifications essential for your control system hardware requirements. All PLC manufacturers layout their product line-up depending on system complexity.
Most PLC hardware is sold as reconfigurable rack chassis. Basically you will find the CPU which is the master brain which can be supplemented with I/O device which can be slotted in like cards. Additional complex systems which needs servo motor will have servo card to connect with servo driver, communication bus cards like CAN-BUS, PROFIBUS and DEVICENET and sensor cards for special sensors like RTD temperature sensors and level sensors.
So work out you IO devices list, then have the necessary hardware and software needed. You will need additional hardware necessary for for fancy touchscreen technology HMI, line automation and online diagnostic and asset monitoring functions. That’s what sort of guy with mechanical background can approach complex automation problems.
The solutions may vary determined by different manufacturer offering particularly if you use beckhoff based systems. A good way to start may be to work with existing machines so that you can discover the basics. Then go have a few catalogs from reputable manufacturers to understand what industry provides. I usually suggest individuals to go through Omron catalogues. They also have a no cost automation web based course which will educate you on the baby steps needed.
You ought to be capable to design complete PLC systems: architecture design, hardware specfications and selection, logic narratives, logic programming, connection drawings. Everything. Perhaps you simply need some additional training about the specifics of each bit of kit, concerning how to program or properly connect them, but it is not nuclear physics, a great mechanical engineer should probably excel with this as any other engineer. The most important element of control system design is always to understand the process you’re going to control as well as the goals you would like to achieve.