Pressure switch problem

[Wiz]

Hey everyone

We have put a pressure switch on our pneumatics system. I programed it to turn of the compressor, but I don't know how to set the pressure it should turn off at. When the compressor runs, the pressure will go up to 110 psi then run out the release valve. Does anyone know how to program a pressure switch to turn of a compressor?

I want the pressure to switch the compressor of at about 100 psi

I am using labview, I am also a first year programmer, so please keep it simple.

thanks

[Mark McLeod]

The pressure switch that came in the Kit is set for 115-120psi.
There's no way to reset that.

The pressure relief valve that came in the Kit should have been preset for 125psi, but obviously yours is set too low for the pressure switch to work. You need to adjust it. There are directions in the bag it came in.

Originally Posted by Team Update 11

If the relief valve is not set to 125psi, teams are required to adjust to release air at 125psi.
The valve may or may not have been calibrated prior to being supplied to teams.

[NinjaWithBurnin]

Continuing this thread for Wiz; (we're on the same team)

Ok We've reset the pressure release valve to hold pressure until 120 psi, but our pressure switch still won't turn off the compressor.

our compressor is controlled by a spike, and I programmed the pressure switch to turn off the spike.

does anyone see a problem I'm missing?

Also we know its NOT a problem with wiring as we've tested all the wires and spikes

[Mark McLeod]

Does your compressor code resemble this in Begin.vi with a Close in Finish.vi and absolutely nothing else?

The only reason I ask is that sometimes teams try to control the Pressure Switch and the Compressor Relay directly in Teleop.vi or some other inappropriate place.

You might try temporarily upping the Pressure Relief Valve to 125 or 130 psi to see if your Pressure Switch is set to trip a smidgen high.

Your compressor Spike wiring is obviously working. The only possible pressure switch wiring problem would be a short. It obviously trips the DIO so the code turns on the compressor. You could try swapping out the pressure switch for another one.

[NinjaWithBurnin]

Yes we do have a proper Open and Close function, but I was also putting the control for the pres. switch into the Teleop. section of the code.

is that wrong? where should the code for a pressure switch be? I tried putting it into the Main vi but there was still no difference.

[NinjaWithBurnin]

Also is the pressure switch a DIO input in Labview?

[Mark McLeod]

No other code is necessary at all.

The Compressor Start in Begin.vi actually sets off a parallel task that constantly monitors the pressure switch and turns the compressor on and off as necessary during the entire time your robot is on.

The Pressure switch does go into, usually, DIO 1 by default. You specify which DIO in the Compressor Open.

[NinjaWithBurnin]

Yes both our spike and pres. switch are in the #1 slots. The only code I have currently is in the Begin and End code.

In the Begin. It starts with an Open. block with both registrys set, then it continues into a Registry Set func. then to a Start func. after that it goes into the Error relay

Is that right? I'll try messing around with it a bit more but I've been stuck on this for a week

I don't know how to post a pic of what i'm doing so I hope thats clear

[NinjaWithBurnin]

OK I re programed to match the diagram you posted earlier but now the compressor wont turn on at all

any ideas?

[Mark McLeod]

Do you have another DIO Open that you were using with the pressure switch before?

Multiple Opens clobber one another and the Compressor Open counts as Opening DIO 1 and Relay 1. Just make sure an Open of DIO 1 doesn't show up anywhere else.

I think the order you have in Begin sounds fine.

You can double-check the Pressure Switch wiring - only the black & white wires from a PWM cable.

[NinjaWithBurnin]

Woohoo!!!! Finally got it working! turns out there was some unesesary code left over!

thanks for your help, the compressor works great now

[Mark McLeod]

Happy competing!

[George Nishimura]

This is slightly unrelated, but it doesn't deserve its own thread. Our compresser.stop() [we use java] won't stop the compressor, but if we createa a DigitalOutput with the same channel as teh compressor, and set it equal to false, it does stop. Compressor.start() works though.

Kind of a random one, and not a big deal (because of the DO adjustment) but curious as to what we are doing wrong.