I’m an area service engineer for food packaging machines rather than an automation specialist, however i can present you with few hints.
For those automation systems to work, you have to first possess a clear and detailed mechanical plan effortlessly details finalized. Whenever you do this, you should specify the kind of motions involved, e.g.: linear or rotary. This lets you know the number and kinds of motors and actuators you may need(servo, ac single phase, ac 3 phase, pneumatic actuator).
For each 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.
They’re your output devices, then you need your input devices to get lay out. This is level sensors, flow sensors, proximity switches along with other devices when needed. The key reason why i’m stating out this routine is always to enable you to define the specifications essential for your control system hardware requirements. All PLC manufacturers layout their product line-up determined by system complexity.
Most PLC hardware is sold as reconfigurable rack chassis. Basically you have 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 may 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 figure out you IO devices list, then receive the necessary software and hardware needed. You may want additional hardware necessary for for fancy touchscreen display HMI, line automation an internet-based diagnostic and asset monitoring functions. That’s how a guy with mechanical background can approach complex automation problems.
The solutions varies based on different manufacturer offering particularly if you use beckhoff based systems. A good way to start may be to work on existing machines so that you can study the basics. Then go have a few catalogs from reputable manufacturers to understand the market can give. I always suggest website visitors to go through Omron catalogues. There is also a no cost automation online course that will teach you the baby steps needed.
You need 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 additional training about the details of every piece of apparatus, on how to program or properly connect them, yet it’s not brain surgery, a great mechanical engineer should probably excel for this because other engineer. The key aspect of control system design would be to view the process you are going to control along with the goals you need to achieve.