I’m an area service engineer for food packaging machines and not an automation specialist, on the other hand can provide you with few hints.
For all automation systems to be effective, you need to first have a clear and detailed mechanical plan with all details finalized. If you accomplish that, you have to specify the kind of motions involved, e.g.: linear or rotary. Each day understand the number and kinds of motors and actuators you will need(servo, ac single phase, ac 3 phase, pneumatic actuator).
For each 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(much more conveyors, liquid tank level control pumps or rollers).Servo motors need Servo drivers to regulate their precise movement.
These are your output devices, you will want your input devices to become lay out. This is level sensors, flow sensors, proximity switches along with other devices as required. The reason i’m stating out this routine is usually to enable you to define the specifications essential for your control system hardware requirements. All PLC manufacturers layout their product line-up based on system complexity.
Most PLC hardware is sold as reconfigurable rack chassis. Basically there is a CPU the actual master brain which can be supplemented with I/O device that can be slotted in like cards. Additional complex systems which needs servo motor may have servo card in order 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 workout you IO devices list, then obtain the necessary software and hardware needed. You may need additional hardware needed for for fancy touchscreen technology HMI, line automation and online 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 good way to start can be to focus on existing machines so that you discover the basics. Then go get a few catalogs from reputable manufacturers to understand what the market has to offer. It’s my job to suggest people to go through Omron catalogues. They also have a totally free automation online course that can educate you on the newborn steps needed.
You should be in a position 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 specifics of every bit of equipment, concerning how to program or properly connect them, however it is not rocket science, an excellent mechanical engineer should probably excel about this every other engineer. The most crucial facet of control system design would be to see the process you’re going to control as well as the goals you would like to achieve.