I’m a field service engineer for food packaging machines instead of an automation specialist, however can give you few hints.
For many automation systems to function, you have to first possess a clear and detailed mechanical plan with all of details finalized. Whenever you do so, you need to specify the type of motions involved, e.g.: linear or rotary. This allows you to understand 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 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 manage their precise movement.
These are your output devices, you will want your input devices to get determined. This is often level sensors, flow sensors, proximity switches along with other devices if required. The main reason i’m stating out this routine is 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 you will find the CPU which is master brain which is supplemented with I/O device that could be slotted in like cards. Additional complex systems which needs servo motor will 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 figure out you IO devices list, then get the necessary hardware and software needed. You might need additional hardware essential for for fancy touchscreen HMI, line automation and internet-based diagnostic and asset monitoring functions. That’s how a guy with mechanical background can approach complex automation problems.
The solutions may vary according to different manufacturer offering especially if you use beckhoff based systems. A sensible way to start is to work on existing machines so that you can educate yourself on the basics. Then go get yourself a few catalogs from reputable manufacturers to understand the market is offering. It’s my job to suggest visitors to go through Omron catalogues. Next to your skin a free automation online course that will teach you the child 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 all you need is additional training on the specifics of every piece of it technology, concerning how to program or properly connect them, but it’s not brain surgery, a good mechanical engineer should probably excel about this just like any other engineer. The key part of control system design is always to understand the process you’re going to control as well as the goals you wish to achieve.