labview comressor help!!

[mole]

hey everyone,

ive been trying to program our prototype chassie with a piston on it but i cant seem to get the compressor or the pistons to work. The compressor is hooked up to relay 1, relay 2 and 3 are for the solonoid. The pressur switch is on D I/O 1. I've tried both a hand made program and the example tutorial given with labview.

Please help!

[Mark McLeod]

The LabVIEW "Solenoid with Compressor Example"
default connections go to:

Pressure Sensor - Digital Sidecar DIO 1
Spike for compressor - Digital Sidecar Relay 1
Solenoid - Pneumatic Bumper/Breakout 1

The compressor should have run automatically and the solenoid fire when you push the Front Panel button.

It sounds like your solenoid was wired elsewhere.
What happened when you ran it? Anything at all?

[mole]

nothing whatsoever... idk why. ill try again tomorow and ill repost my results

[Mark McLeod]

Did you download or just use run?

The example is only setup for a single solenoid, not a double as you seem to be testing with.
The compressor should have run regardless.

[mole]

ive been clicking run.. how do i actually download it

[Joe Ross]

Have you completed the benchtop tests in the control system manual (up to at least section 1.6.7)

[mole]

yes, i have done the benchtop tests

[mole]

i still cant get it working!

[EricH]

Originally Posted by Mark McLeod

default connections go to:

Pressure Sensor - Digital Sidecar DIO 1
Spike for compressor - Digital Sidecar Relay 1
Solenoid - Pneumatic Bumper/Breakout 1

Disregarding the programming for now--You do have a spike in the system, right? (And, for the programmers here--what effect would not having one have?)

[mole]

we have a spike attached to the compressor and without having a spike, the compressor wouldnt get a signal to turn on and off..

everytime i run the program, the spike flipes on and off instally so it could be the program but idk

[cabbagekid2]

Did you figure out your problem? We've been having trouble getting the compressor to work with the pressure switch also. Just started playing around with Labview and the cRIO so it'll take us some time to troubleshoot.

What we did:
In Periodic VI we put the code from the compressor example (minus the COM stuff). Wired up the Relay & Dig I/O accordingly. No solenoid for now since we're just trying to get the compressor to work.

What happens:
After we hit the run button, the relay just stays orange. The pressure is 0 psi and nothing changes. One question...do we need a pull up resistor for the Dig I/O for the sidecar? I remember reading somewhere that we need that...but it might have been only for the driver station.

[Russ Beavis]

http://usfirst.org/uploadedFiles/3-F...s-Rev-0-5a.pdf

Per chapter 3.5.3, there are 10k pull-ups to 5V on all of the sidecar's GPIO. You should be able to simply attach the pressure switch to the "signal" and "-" terminals for GPIOx (the outer two terminals in each GPIO's 3-pin set, I don't remember which one is intended to be used for pressure control).

Russ

[paulcd2000]

Having done a pretty detailed run-through of the compressor code, i've decided that it's a load of rubbish. It's far easier to write your own compressor code than it is to actually use the library provided. In fact, i can see no way that the provided VIs would EVER work, but i could just be missing something. The code needed is quite simple. feed a relay and a DIO in, and then feed the DIO value to a case structure. If it's true, stop the compressor. if it's false, run the compressor in reverse (at least, that's what worked for us).

[Luke Pike]

I'm not sure if they already know this, but solenoids are connected directly to the solenoid breakout bumper, no need for a relay.

As for the compressor, Here's an example of what I did when we transplanted the control system into Sidewinder back in September.

[Joe Ross]

Originally Posted by paulcd2000

Having done a pretty detailed run-through of the compressor code, i've decided that it's a load of rubbish. It's far easier to write your own compressor code than it is to actually use the library provided. In fact, i can see no way that the provided VIs would EVER work, but i could just be missing something. The code needed is quite simple. feed a relay and a DIO in, and then feed the DIO value to a case structure. If it's true, stop the compressor. if it's false, run the compressor in reverse (at least, that's what worked for us).

I agree that the compressor code is confusing (especially when I was looking at it as a new LabVIEW programmer). However, it does work, and there's a couple reasons it was written the way it was. While writing your own code to control the compressor is easy, it isn't easier then using the compressor VIs.

First how it works: Compressor Open spawns a new task that runs the compressor run VI. If you want to see how everything actually works, look at the compressor run VI (double click on the static VI reference in compressor open).

The reason that it works this way is so that it runs in both telop and in autonomous independent (which is also a separate task). If you chose the iterative style, it wouldn't be hard to do it in both auto and telop, however it's not as easy if you want to do a linear style programming in autonomous independent. By putting it in a separate task, you make sure it always works, regardless of the programming style of the user. Secondarily, it's a good example of how to spawn a task and do inter-task communication, which I know I appreciated.