I am a PLC and HMI guy. After college, I worked for machine builders and then a few factories. I recently worked for a company that supplies controls talent to other companies. While there, I worked a contract at Stellantis making changes to a production line that welds sheet the sheet metal that becomes a car body. I also worked another contract at a Walmart distribution center commissioning conveyor systems and robots. Now, I'm back to machine building. A PLC (programmable logic controller) is a computer tailored to a machine. A HMI (Human/Machine Interface) is typically a touch screen that communicates with the PLC to display information about the state of the machine and allows control of the machine. I've learned that there needs to be a balance between the amount of effort put into the PLC and HMI code development. I've seen many machines that function well, but are unpleasant to work with because the HMI work was not great. If the operators hate the machine, productivity will suffer. It's not just the people buying the machine that matter. The operators matter, too. I find this line of work very frustrating but also very satisfying. It is cool to consider that the code I have written is still functioning in various places around the world. Still, I am getting tired of this. I hope one of my inventions will pay, instead, some day.
