Solenoids acting weird

The solenoids attached to our pneumatic breakout are acting strange. The double acting solenoids are workign as a single stage solenoid.
For example: pin 1 and 2 are connected to a double acting solenoid. Pin 1 extends the piston and pin 2 retracts the piston. Pin one is triggered form the start and when you trigger pin two the piston will retract as long as the trigger is pressed, when the trigger is released the solenoid shoots the piston back into pin 1 position.

We tried changing the solenoid and pins on the pneumatic breakout but that did not resolve the issue. The code does not seem to be the issue as we are using the same code as the one from championship, also the module is showing the lights as in what pin should be high but it does not seem to work. if somebody knwos the problem and can help us it would be great.

The LEDs on the solenoid module are showing just what the code is commanding.
So for a double solenoid, one light will be on while the other is off. Then the reverse. If what you see isn’t what you want, then it is only a code issue.

Once the LEDs are doing what you expect, then you can look at pneumatic electrical issues.

LEDs are doing what expected but solenoids are not. So it should be electrical but we put on a new solenoid on the same breakout with new PWMs but we got the same results, it did not work.

So electrically, follow the trail looking for indicators that are not as they should be.
Some of this is obvious, but included to complete the detail for others.

  • Verify that you are using a solenoid breakout (sets of two pins), rather than an analog breakout (sets of three pins). A standard 3-pin PWM cable will not fit a solenoid breakout (2-pin) without some modification or removal of the solenoid breakout protective cover.
  • Use a multimeter to verify that the solenoid breakout pin 1 (signal-to-ground) and pin 2 (signal-to-ground) mirror just what the LEDs are doing. The signal pin should read 0v when the corresponding LED is off and 12/24v when the corresponding LED is on. Voltage should match what you wired into the breakout 12 or 24v, and that voltage should match the solenoid rating of course.
  • Verify the solenoid wiring. Double solenoids have two sets of red/black wires. One set from each side. One red/one black connects to one pair of pins on the solenoid breakout. So solenoid breakout pin set 1 (red/black) will connect to one side of the double solenoid, while pin set 2 red/black connects to the opposing side.
  • With a solenoid connected, each side of the solenoid should have an indicator light that also lights to match the Solenoid Module LEDs.[LIST]
  • Disabled = no solenoid lights would be lit
  • Enabled = only one side of the solenoid should be lit at a time.

*]Double check the polarity of the wiring to each side of the double solenoid. Reverse polarity will light the indicator, but won’t fire the solenoid.[/LIST]

Thank you very much Mark McLeod. I will to look for the values as soon as i get a chance to work on the robot.

I checked the reading on the solenoid and it displayed 11v, strange as we are using 24v solenoids. After troubleshooting it was figured that the Solenoid breakout was only receiving 11v when it was still connected to the regulated 24v port on the Power Distribution. The cable was changed a few times as that was the only component in doubt of cutting the voltage. We tried to check if the cRio was a problem so the cRio was then swapped with our practice cRio and it turned out to work after that. The problem is not found yet for the loss of voltage but the problem is temporarily fixed for the time being.

Thanks for the follow-up.

A mild short on one of the 24v lines, one of the connectors, or in the cRIO or solenoid breakout will do what you describe.
The 4-slot cRIO will work down to 9v, so the short wouldn’t have been obvious if if hadn’t been a 24v solenoid.

If you want to track it down further now that you have a working setup you can do a simple part swap to isolate the culprit. Leave all the working parts connected and your multimeter running, while testing single components one at a time by connecting them.
Whatever is the same from the old setup has been pretty much eliminated. If the 24v PD/cRIO/Solenoid module connectors and wires are the same in both setups, then it’d point to whatever was taken out. The cRIO itself, the solenoid module or breakout depending on what has been replaced.

We had the exact same issue happen exactly 2 days ago. A 24v sensor being powered by the solenoid breakout had shorted out. This resulted in damage to the breakout, and to the 24v DC-DC converter in the PDB. Check the lights on the PDB and ensure that the 24V light is on. If it isn’t, you’ve probably fried the 24V line on the PDB and it will need to be replaced. Hopefully the extent of your damage isn’t as serious as this :ahh: