Ok, so i was in the shop the other day setting up computers, and one of my friends was driving our bot with the transplanted system in it when all of a sudden is stopped working, I saw that the bot still had power, so i figured the battery must too low to move the bot around, so i swapped out the battery and it still didnt work. I took a closer look at the panel and noticed the cRio did not have any power, even though the Distribution panel said it had output to the 24v, but not to the camera…I was not too worried about the camera, but i thought the cRio may have been shot! None of the led’s were lighting up, and the board said it should have power. I pulled out the connectors, rewired them, and it still did not work. Thats when i started stressting out! anyways it turns out that the battery that i had put in was only registering 4.6v…which was pretty strange, considering it was from '08.
anyways long story short…If your cRio does not power up, even though the Power Distribution board says it has power, check your battery. Also, the camera may be the first to not get power from the board with a really low battery!
The camera 5V light is only going to tell you is your power is below 5V. Or at least, below a little above 5V. The camera power supply is what’s known as a “buck” power supply, meaning it reduces some variable higher voltage (~12V) to some stable lower voltage (5V). It’s not capable of increasing voltages, so it will stop working when the battery drops below 5V.
The 24V power supply is a “boost” power supply, meaning it increases some variable lower voltage (~12V) to a stable higher voltage (24V). It will keep the 24V stable over a considerable range of input voltages, but it can’t work miracles. Or, at least, it has to be designed with some minimal constraints in mind. So if your voltage drops below (I think) 6-7V, then it will stop working. However, that’s much lower than the tolerance of the IFI controllers, which is why we’re not using backup batteries this year. Plus, if your battery gets that low, it’s not going to be operating any motors anyways.
I have it on good authority that the 24 volt voltage convertor that is intended to power the CRIO stops functioning when the input voltage is 4.5 volts or less. Make that 5 or 6 volts to be sure and you should be alright. A dead battery could register a very low terminal voltage under load and then return to 12 volts with no load on the battery. That is why, I don’t recommend using a voltmeter to check for battery charge condition.
Our cRIO shows similar symptoms as those previously mentioned, however our problem is not remedied by replacing the battery. Everything was hooked up normally, but it spontaneously failed.
We know that the cRIO was supplied with ample power. When we try to set up the electrical system, everything but the cRIO powers up. We believe that the problem resides within the cRIO. Where do we send it to get it fixed or replaced?
ours has the same issue; the crio simply stopped functioning. it’s not the voltage; we tested the 2a fuse that is soldered to the board inside the chassis and it is blown. We NEED to replace the crio!! Any ideas who we call?
Out team had the control system on the bench, doing some tests. We had five motor controllers hooked up (our sixth one was removed) and two were attached to motors. Since it was not entirely set up (no analog breakouts or other important pieces plugged int), we didn’t have a battery voltage readout on the DS. When I went to program it, only one of the two (small) motors would run. The other simply wouldn’t run. We switched the motors around, used different PWM outputs and speed controllers, but still couldn’t get the motors to run. A while later, the DS lost communication with the cRio. We noticed all the lights flickering on the various components (partially synchronized, partially chaotic). After shutting it off, we took a multimeter to our battery terminals (still connected to the breaker), and thought something was wrong with our reading. We were only getting a little over 3 volts.:ahh: When we disconnected it and tested the battery alone, we also got a little over 3 volts. After getting a new multimeter (neither of us could believe it would even power on with 3 volts), we tested again. It was a little over 3 volts. We replaced the battery with one right off the charger (we tested it and it had over 12 volts) and the system worked fine. We realized noone had replaced the battery in several days of use. Moral of the story: next time we should check the battery voltage.:yikes:
I think it is important to add a little info here. If you run your batteries down to 3 volts (or a voltage that will not power the CRIO) it is possible that some chargers may not begin a charge cycle. Smart chargers may see that condition as you trying to hook up a 6 volt battery or something even less. Establish some method of getting batteries on the charger at regular intervals in your build and test season. Also, do not try to charge batteries that are warm to the touch. Wait an hour, just like swimming and eating.
The wonderful people at National Instruments were very responsive when we called to describe our problem. We had a replacement cRIO the next day. Thank you NI!!
The other simply wouldn’t run. We switched the motors around, used different PWM outputs and speed controllers, but still couldn’t get the motors to run. A while later, the DS lost communication with the cRio. 
We noticed all the lights flickering on the various components (partially synchronized, partially chaotic). After shutting it off, we took a multimeter to our battery terminals (still connected to the breaker), and thought something was wrong with our reading. We were only getting a little over 3 volts.:ahh: When we disconnected it and tested the battery alone, we also got a little over 3 volts. After getting a new multimeter (neither of us could believe it would even power on with 3 volts), we tested again. It was a little over 3 volts. We replaced the battery with one right off the charger (we tested it and it had over 12 volts) and the system worked fine.
We realized noone had replaced the battery in several days of use. Moral of the story: next time we should check the battery voltage.:yikes: