The coolest tip I can give to a C programmer would be that 110V is on one side of the ladder, and NEUTRAL is the other side. Each step (rung) of the ladder is a Boolean switch (or multiple) to turn ON a light. FYI: Rockwell inspection rungs are different than standard Boolean logic, so it can be tricky. But, with your procedural knowledge, it just takes a bit of converting bools to electrical ‘switches.’ PLCs (the controller) are simply arrays of Boolean-mapped (as in truth tables) relays in an electrical panel … really, really small relays. I always have to take a refresher video when I convert, as I program in C and ladder. Typical Rockwell ladder rung: If (on the left side of the ladder rung) the switch is closed (e.g. light switch)… then complete the circuit to the light circuit, which is represented as a COIL on the right of the rung. Execution order (PLC ‘scan’) is top-to-bottom of rungs. Rockwell uses ‘tasks’ to break ladders into logical sections. Good luck. Rockwell is the best.

- Pete

You can email me. In engineering, it is a very common programming standard, along with other standard you would be more familiar with. It can be converted to a more procedural style with fancy Allen-Bradley tooling, modified, then converted back. You usually want a systems integrator to do it, because you’re running equipment. Give me a shout. pjschieck@aol.com

Pete Schieck Legal/business refs: build-a-concert.com/legal