close MarkF, But not quite.
here is a sketch i drew of what i'm after.
Each sensor will be on its own cable, up to 50ft (depending on machine size, as the cable needs to travel through Cable Drag Chains), and have two LED's. The sensors are encased in clear resin, and when the LED lights up, the whole case lights up that color. So the visual effect is neat looking. So, when the sensors is plugged in and in it's normal state, a green LED is lit (or blue if the customer chooses blue instead), and then when the magnet triggers the sensor, it will switch from the green to the red color, when the magnet is pulled away, or the machine is done homing, then it switches back to the green LED...Normal state.
Now, when the user wants the switches to work in normally open mode (instead of the default normally closed), then a jumper is selected and the optomos will switch to that. So, in Normally closed state (default), the LED inside the optoMOS will be ON, indicating that the optoMOS is fully turned ON and in normally closed mode and will only turn off when the sensor is triggered. But, if the jumper is selected, then that LED is off and ONLY turns on when the sensor is triggered, thus, normally open mode. Each normally open or normally closed selection will also have a 2 color identifier to let the user know which is selected.
Now, there will be a front panel that will have the matching LED's of each sensor. So when the sensor is triggered, not only do the colors switch on the sensor, but they also switch on the front panel.
Also on the front panel will be a test switch that will turn on all LED's in the circuit, so that they can be identified easily if one has burned out. That test switch will have a red LED that will turn on when the switch is pressed.
Now, for the rear panel where all the connections for the sensors are made, there will be two LED's on that panel. A green (or, again, a blue if user desires) and a red. The green stays on, but switches to a red color if a sensor has triggered (ANY sensor). Kinda like the jack where your Ethernet cable plugs into, as it blinks when data is received.
I also want to make it so later, an LCD or graphical LCD can be plugged in. Later in the future, I want to add features such as monitoring stepper positions that will read out on the display, as well as maybe some other things I may think of, so I will need some extra inputs on the Microcontroller for that.
The rear panel will also have some kind of a plug in sensor on it to monitor if a sensor has been plugged in. If a sensor is NOT plugged in, then all LED's on the front panel for that Sensor jack will be turned off, as well as the optoMOS and NC/NO jumper LED's. There's no sense in having visual indication for something not even plugged in.
Also, if there is another option...the optoMOS is abit expensive at $0.85 each when bought in 100. But, I am not sure that a transistor based (i.e. optoisolator) will work. It might make too much of a voltage drop across the optoisolator.
I'd like to have the voltage down the cables for the sensors to operate at 24volt if possible. That would be at par with some of the more expensive industrial machines whose proximity sensors and mechanical switches operate at 24volts.
Currently, I have four 28awg wires inside the double shielded cable going to the sensors. I would like to reduce that amount, so that the cable can be smaller diameter, if possible.