No Battery Voltage

I do appologize if this is in the wrong spot, I’m in a kind of hurry. (I have 7 hours until I have to get ready to leave for the Regional again tomorrow) Along for any spelling errors, as I do not have a mouse and have gotten this far using only a keyboard. By the way, the “Forum” doesn’t show as a link with “tabbed” to… made things kinda hard. :stuck_out_tongue:

Anyhoo, onto the good stuff. We have almost completely passed inspection, except for one fault. The Battery Voltage will not show. (It reads 00.0V) I know that the voltage gets all the way to the module on the CRio. Past that I don;t know how to tell. The CRio is indeed getting power, and we are connected. We have switched out the modules, and switch the chips on them (On the off chance on chip was bad and one module was bad.) We then asked the NI rep to help us out. She rechecked everything, and decided that our CRio may be bad. We checked out a spare CRIo from the spare parts. No difference. It’s still reading 00.0V She suggested that we uninstall the DS program and reinstall just in case. The programmer is currently doing that, but we wont know if it works until tomorrow.

My question to you is, if this reinstall does not work. What else could be the cause? (We are tethered directly to the robot.)

Thank you for your time,

Do you have the analog input connected to 12v from the power distribution board? The voltage display reads an analog input, it does not measure the power that runs the cRio itself.

And do you have the analog module in the correct position in the cRio?

Make sure you have the correct version of both the DS ( and cRIO image (2010_V20).

Also make sure the analog module is properly plugged into slot 1 of the cRIO. The analog breakout should be plugged into the Analog module and powered. Make sure the power LED on the analog module turns on when the robot is powered.

The last thing to check is that the jumper is properly installed on the outside two pins of the 3 pin header on the Analog breakout. Also if you have a different jumper to try, switch it out, I’ve heard a team or two that had a broken jumper and swapping it out fixed the problem.

The battery voltage is read through the analog module.
Analog input number seven must be have a jumper on it in order for the battery voltage to be read.

More info here.

Also, check your code. Make sure you aren’t accidentally trying to use Analog 8, since that is where the battery voltage plugs in to. When I first started using the cRIO I accidentally did this and lost the battery voltage (it read 0.0). It took me a little while to figure out my error.

I saw the same thing in Dallas, and it took awhile to troubleshoot.

To summarize all the good advice you’ve already received.

Use a MM to verify the voltage at the analog breakout. Verify you have a jumper on the correct two pins. Verify this is in slot 1.

If no luck, swap analog breakouts – they are the weakest link.
If no luck, swap the module.

If no luck, open Robot Main, open the Start Communication subVI. Scroll to the right and find the place where Get Average Voltage is being read. Probe the value and the error output. See if the value is correct at that point but not getting to the DS properly (never seen this, but worth checking). Verify you aren’t getting an error reading the voltage because the channel is reserved elsewhere.

In Dallas, I had to switch things to slot 2 to get it to work. The place you probed in Start Communications has a constant with the slot. Move the analog breakout or module and breakout to slot two. If this works, you need to explain to the inspector that the other slot doesn’t work and hopefully they will let it pass.

I didn’t have time to look at things more closely in Dallas, but suspect a bent pin or swarf in the connector.

Greg McKaskle

Thank you everybody for the help! :smiley: Though… That was the weirdest thing ever… Eventually the NI lady(Olivia) decided that maybe it was our DS. (Which would make sense because it was one from spare parts to replace our one
with the cracked screen.) So she tried building and deploying from her laptop. She then ran tethered her laptop to the robot. And would you looky there… battery voltage… So it turns out our DS is corrupted somewhere… Luckly for us, she let us borrow her laptop the rest of the day.

A HUGE thanks to Olivia and all of the volunteers who helped us through this! :smiley: