No battery voltage readings on DS!

[team3039]

We've tried to replace the analog breakout board on the cRio, and the jumper is hooked up to the two outer pins. Still no battery voltage readings on the DS. Does anyone know what's wrong?

[Mark McLeod]

Is the green power light on the Analog Breakout board itself brightly lit?
Do you have power from the Power Distribution Panel wired directly into it?

[team3039]

Yes, The green light is brightly lit and I believe it's also powered from the power distribution board.

[Mark McLeod]

Is the Analog Module labeled NI 9201?
Is the Module in the first cRIO slot?

[team3039]

Yes, and Yes.

[Mark McLeod]

Pull the Analog Module out of the chassis and visually inspect the pins in the bottom of the chassis. Look for metal debris or bent pins.

[team3039]

We did, and everything seems fine.

[Mark McLeod]

8-slot or 4-slot cRIO?

[team3039]

8-slot

[Mark McLeod]

The 8-slot's collect metal dust and debris inside.
If it's a used one, have you cleaned out the case lately?
It should be cleaned each year before being mounted on a new robot.

It does weird things when there is dust inside, so that might be a possible cause.

I assume nothing else is plugged into the Analog ports that might cause a short.

You can test the Breakout with a multimeter to see the battery voltage on the pins you put the jumper on. Measure from the pin to any ground.
Use the multimeter to verify continuity through the jumper in case it isn't really a jumper. (I only say that because I once found a team using a cable connector instead-it didn't work.)

[team3039]

I will check on it tomorrow. I appreciate your help.

[Joe Ross]

Does the imaging tool detect the analog module?

[billbo911]

We had this issue a couple years ago. It turned out a programmer had assigned the same analog input used for monitoring battery voltage to a second device.

[Mark McLeod]

Originally Posted by billbo911

We had this issue a couple years ago. It turned out a programmer had assigned the same analog input used for monitoring battery voltage to a second device.

That would be Analog Input 8

What the jumper does is steal the signal pin from that analog input for use as the battery detector.
If the jumper is put over the other (inside) pin then analog input 8 acts like a normal input in the alternate analog cRIO module slot.

Opening Analog Module 1's analog input 8 is a no-no because it's already opened by the battery monitor.

[Alan Anderson]

Originally Posted by Mark McLeod

Opening Analog Module 1's analog input 8 is a no-no because it's already opened by the battery monitor.

If your program needs to know the battery voltage, there's a handy Get Robot Battery Voltage.vi in the Driver Station function subpalette.