I am currently finishing my A.S. in Engineering Technology. My Capstone course is to wire up a complete S7-1200 system using a 1214C DC/DC/DC CPU. There have been no courses that have explained exactly how they are wired. Only programming, which I am pretty good with. There is a 120VAC to 24VDC power supply. They want it to be wired to switches and lights for a simulator. I am just not sure exactly how the I/O's are wired. Is is sinked or sourced? As far as I know, one sends the ground to the output, and one sends the 24v to the output. I would love to speak with someone on how to wire this, as once I graduate, this is what I want to be doing, but I am stuck in a hard place as none of my classes taught us how to wire the PLC's and even worse, the programming class was all about AB PLC's. I have not learned about Siemen's at all. They should be pretty close to the same, but I know there has to be some differences. Also, how they have it set up, there are 2 power supplies on the plastic panel just to the left of the picture. This seems to me as this is a sinking I/O. Am i off?