I have a Raspberry Pi A+ and I've heard that there's a serial on
/dev/serial0, which is actually symlinked to
/dev/ttyAMA0. What I would like to achieve is connect the beckhoff I/Os to the raspberry and read/write in/outputs using Python's MinimalModbus library. The HMI adapter's power led is green, but the activity led is not doing anything. Python just exits with an error: "No answer from device".
Things I posess
Sorry for the crappy schematic, I'm not an engineer. I know it's not proper to connect some of those wires together, but it's easier to explain it this way.
The code used is the example code on this page.