I’m an area service engineer for food packaging machines and not an automation specialist, however can give you few hints.
For those automation systems to operate, you should first use a clear and detailed mechanical plan with all of details finalized. Whenever you do this, you have to specify the kind of motions involved, e.g.: linear or rotary. This lets you have in mind the number and types of motors and actuators you will need(servo, ac single phase, ac 3 phase, pneumatic actuator).
For each and every 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(more like conveyors, liquid tank level control pumps or rollers).Servo motors need Servo drivers to regulate their precise movement.
These are generally your output devices, you’ll need your input devices to be set out. This can be level sensors, flow sensors, proximity switches as well as other devices as needed. The main reason i’m stating out this routine is always to permit you to 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 master brain that is supplemented with I/O device which can be slotted in like cards. Additional complex systems which needs servo motor could have servo card to get in touch 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 software and hardware needed. You may want additional hardware essential for for fancy touchscreen display HMI, line automation an internet-based diagnostic and asset monitoring functions. That’s the way a guy with mechanical background can approach complex automation problems.
The solutions may differ based on different manufacturer offering particularly if you use beckhoff based systems. A sensible way to start may be to work on existing machines so that you will discover the basics. Then go obtain a few catalogs from reputable manufacturers to understand what industry provides. I usually suggest website visitors to go through Omron catalogues. There is also a free of charge automation web based course that may show you the baby steps needed.
You have to be able to design complete PLC systems: architecture design, hardware specfications and selection, logic narratives, logic programming, connection drawings. Everything. Perhaps you just need to additional training for the more knowledge about every piece of equipment, regarding how to program or properly connect them, however it is not brain surgery, a fantastic mechanical engineer should probably excel on this because other engineer. The key aspect of control system design is to understand the process you are likely to control and also the goals you would like to achieve.