connecting digital sensors to RC

i have a question:
there are some digital sensors we got with the KOP:
the allen bradley photodetectors
the psi sensor that’s tripped when pressure gets to 115 psi (correct me if im wrong)
and the limit switch.

the board has digital i\o connections - SIG 5V+ and GND.
my question is, take the limit switch for instance:
how do i connect it to with out short circuiting the board?

thanks in advance.
edit: i understand connecting a sensor to the boards 5v power, and the third leg to the SIG like with the GTS, but what do i do when i dont have a third SIG connection?

What you will want to do in the case of a limit switch or custom switch etc. is ground the signal wire. There is plenty of documentation on the RC here. Simple switches like limit switches don’t usually need a power source like that +5V.

I haven’t read anything about those Bradley Photo sensors, but my guess is they do need a power source. Grounding the signal wire works in the case of the pressure switch if it hasn’t changed much since years past. I just hacked a pwm cable and soldered the white and black to the leads.

you confirmed my thoughts exactly thanks!

and about the bradley sensors, i will multimeter the outputs and post the results so there will be no worries about connecting it without overloading the board.

You probably aren’t going to get anything out of them with just the 5V from the board. Here is the tech sheet for the sensors.

So, did anyone figure out how to wire the Allen Bradley sensors?

I cant find any information as to whether they go onto the controller with 5 V, or onto the battery with 12 V.

If they do go onto the battery, how can i get the signal of of them?


The allen bradley sensors will work with voltage anywhere from 12 to ~28 volts I think, it’s printed on the side of the sensor. I got them out and played with them a little today, they’re pretty neat! The two of them make a set, you need to wire the positives of each together and plug it into the breaker panel w/ a 20amp fuse, and the grounds go to the common, either on the rc or on the panel. If you line them up, the LED on the reciever will light up, and when you break the IR beam, it will go out. Then wire either of the signal wires to the signal pin of a digital in on the RC, you pick, one of them is NO and the other is NC. Just playing with them for a little bit, they seem like a step up from the old banner sensors, much more reactive.
Hope this helps.

On the source Allen-Bradley sensor (with the LED), which color wires are connected to the PWM cable? Are any resistors involved? The four colors coming out of the sensor are red, white, black, and green. We have the red connected to a 20amp fuse on the breaker. Black is to ground. What do we do with the green and white??

The post above yours says how :slight_smile: You wire EITHER the green OR the white to a signal pin (via pwm connector) to a digital input on the RC. That’s all you have to do…really! Well aside from the 12v supply which you’ve already done. What’s really cool, though, is you don’t even have to have the signal connected to see if your photosensor is working correctly. The red LED will turn on and off according to whether it is switching on or off. We used BOTH sensors: the two wire one is the source and the 4 wire one is the receiver. We mounted them right next to each other to measure shooter RPM (with a white spot to reflect the IR off of). Just connecting the 12v supply got them working (LED on/off as the wheel rotates). Of course your RC needs the signal in order for your program to do anything with the information, but it’s still nice for troubleshooting (using the red LED that is).