I’m a field service engineer for food packaging machines rather than an automation specialist, on the other hand can provide few hints.
For all automation systems to be effective, you have to first have a clear and detailed mechanical plan with all details finalized. If you do this, you must specify the motions involved, e.g.: linear or rotary. This lets you know 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 may want relay contactors (for single speed discrete/on-off type motors like blower fans and liquid pumps), VFD for speed controllable ac 3-phase motors(similar to conveyors, liquid tank level control pumps or rollers).Servo motors need Servo drivers to manipulate their precise movement.
They are your output devices, you will want your input devices to be set out. This can be level sensors, flow sensors, proximity switches along with other devices if required. The reason why i’m stating out this routine is always to permit you to define the specifications needed 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 there is an CPU the actual master brain which is supplemented with I/O device which can be slotted in like cards. Additional complex systems which needs servo motor will have servo card for connecting 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 workout you IO devices list, then have the necessary software and hardware needed. You may need additional hardware necessary for for fancy touch screen HMI, line automation an internet-based diagnostic and asset monitoring functions. That’s what sort of guy with mechanical background can approach complex automation problems.
The solutions could differ determined by different manufacturer offering particularly if you use beckhoff based systems. A sensible way to start may be to develop existing machines so that you will educate yourself on the basics. Go get yourself a few catalogs from reputable manufacturers to understand the market is offering. I usually suggest visitors to go through Omron catalogues. They also have a totally free automation online course that can show you the baby steps needed.
You need to be capable of design complete PLC systems: architecture design, hardware specfications and selection, logic narratives, logic programming, connection drawings. Everything. Perhaps you simply need some additional training around the specifics of every piece of equipment, on the way to program or properly connect them, yet it’s not rocket science, a good mechanical engineer should probably excel with this as any other engineer. The main aspect of control system design would be to view the process you are likely to control along with the goals you want to achieve.