Analog Input Voltage Verification

I just want to verify to make sure that analog input sensors would return a signal of 5 volts maximum. We want to be able to test all of our things on sidecar and modules, because there has been some coding problems that don’t make sense. if we take a multimeter and send 5 volts into the analog input locations on the module, we won’t fry it right?

There is a bit of confusion in your wording, so I’m hesitant to give a blanket “yes”.

The analog input module (sitting on top of the cRIO) are able to safely measure 5V. In fact, they are able to measure slightly higher voltages as well - their maximum is not 5V.

Many analog sensors will return a voltage in the 0V to 5V range, but there are others that do not. What specific sensors are you using?

Multimeters measure voltage (and other electrical measurements like resistance and current), but they are not typically used to create a voltage.

The digital sidecar does not have any analog inputs. They do have digital inputs.

we aren’t using any sensors (yet), but i noticed what might be a problem with the PWMs (it is an old sidecar from a few years ago). While we were planning on testing those, i thought it was a good idea to test everything else. Since it is an input, i wanted to make sure we can safely put 5 volts into it and see if we get any reading on the programming side of it. Sorry about the multimeter confusion, thought you would be able to send out 5 V on the resistance setting (i am programmer, not electrical but i thought this post would be more appropriate under the electrical, and not so much under programming)

You are correct that a multimeter does produce a voltage when it is put in resistance mode, but this voltage is very small.

The PWM ports are outputs on the sidecar. Do not drive a voltage into them.

no the PWM’s i know how to test (run a motor from them via jaguar). so if we find a 5V .25 A supply we can safely send it into the signal terminal on the Analog In?

Yes. You can apply 5V to the analog inputs on top of the cRIO to test them. Your supply does not need to be able to provide 0.25A, the inputs will draw very little current (on the order of a million times less than .25A).

There is a 5V supply built in to the Analog Breakout. If all you want to do is make sure your program can tell the difference between 5V and 0V on the analog input pin, that’s easy. Each input channel’s three-pin connector contains both 5V and 0V. All you would need is a switch to connect the signal pin to either the center 5V pin or the opposite 0V pin.

The exact same switch setup can test the digital inputs on the Digital Sidecar.