Pneumatics with diode
 

First, I am sorry for such a crude schematic, but I dont feel like making it pretty. Would this even work for having the ability to shoot one piston or all three at the same time, and then have them all retract. And more importantly would this be legal in FIRST?

(grey boxes are solenoids)

Re: Pneumatics with diode
 

See rule R51. Each solenoid must be connected to a separate output on the solenoid breakout. So no it is not legal. You can do the same thing in software though.

I assuming the grey boxes are actually valves with 2 solenoids each?

Re: Pneumatics with diode
 

They are double acting solenoids. So to clarify, this means that no solenoids may be connected by Y's?

Re: Pneumatics with diode
 

Correct. Only one solenoid per output on the solenoid breakout. It is on R51 chart.

You could use spikes if they are 12 volt solenoids. But that is a different story.

Re: Pneumatics with diode
 

Correct me if Im wrong, but it does not say per output on the solenoid breakout, but the solenoid breakout as a whole, so if this idea is correct that you can only power one solenoid per "solenoid breakout" then you could only have one solenoid at 24 volts. I am also unsure about the use of the plural "pneumatic solenoid valves".

Im not trying to argue with you, but if your way is the correct ruling then we will need to think of a new way to run all of our valves, as we have a few of them Yed together.

Per output on solenoid breakout means there are many outputs on one single 24V solenoid breakout. There should be plenty of space for multiple solenoids to be wired to one solenoid breakout.

Re: Pneumatics with diode
 

Frank is correct on this rule. The solenoid module has limited current capability as is referenced in R42. However, this follows the table...
*Multiple low-load, pneumatic solenoid valves, electric solenoids or CUSTOM CIRCUITS may be connected to a single relay module. This would allow one (1) relay module to drive multiple pneumatic actions or multiple CUSTOM CIRCUITS. No other electrical load can be connected to a relay module used in this manner.
The diode shown in your diagram would really not perform as you want. The Spike can be used such that it feeds two solenoid branches with a single device. The outputs independently switch to +12 volts which may help your design. Spikes cannot be used for 24 volt solenoids.

Re: Pneumatics with diode
 

I must be missing something. The way I see it, this statement:

Says you CAN connect multiple pneumatic solenoids to either a spike or the solenoid breakout. Both have the asterisk which points to this statement.

Re: Pneumatics with diode
 

Is there any legal way to control more than 4 24 volt solenoids? Our solenoids only need power to switch, so we do not need to have them always on, only when we switch.

R42 says that we may only have 1 solenoid breakout in the 24 volt PDB port, and Q237 says that you may not have a 12 to 24 volt converter power the breakout, so there is no way to power a second breakout.

Re: Pneumatics with diode
 

You can only 8 solenoids to a solenoid break out. That is all you get at 24V. Your valves have 2 solenoids that is why you can only control 4 valves. Going to a single solenoid valve will allow eight valves assuming you stay in your power budget.

If you read R51 in its entirety & look at chart 4-4 above the reference about multiple loads you will see it only applies to spikes.

Re: Pneumatics with diode
 

Kevin,
R42 for just one 24 volt solenoid module refers to the power supply on the PD. This supply is not capable of the current required for the cRio and two solenoid modules. You may build a 24 volt power convertor as a Custom Circuit and feed two solenoid modules (or one in addition to the one fed from the PD power supply.) provided all other electrical rules are followed.
Martin, the asterisk references the Spike column only in R51.

Re: Pneumatics with diode
 

The answer to Q237 says otherwise. :-( It refers to R53, which prohibits custom circuits from affecting the power pathways to a bunch of things including solenoid modules.

Re: Pneumatics with diode
 

Is there a reason you are using dual solenoid valves? The only reason I can see to use a dual solenoid valve is if you want to set a condition and have it remain after the end of a period (autonomous or teleop). Otherwise, use single solenoid valves. For instance, for a shooter, use a two position two work port valve, so that it defaults to retract (normal or un-powered state). When voltage is applied, the valve shifts and the cylinder extends, and stays that way until power is removed. I would also recommend 12V valves. This way, you can control eight valves instead of just four.

Re: Pneumatics with diode
 

Standby...

Re: Pneumatics with diode
 

The primary reasoning for using them is that they are the Solenoids that we have available to us from previous years. We also purchased more of the same type as we had experience using them and knew that they worked well.

Re: Pneumatics with diode
 

I like Al's solution, but R71 seems to say you cannot hook an output of a custom circuit to the solenoid breakout.

Re: Pneumatics with diode
 

Frank,
I disagree and that is why I am asking the question at this point.

Re: Pneumatics with diode
 

If so, teams that are powering photosensors using the Solenoid Breakout (as we have done in the past) are in violation of R71.

Re: Pneumatics with diode
 

I hope you are right Al. It is a good solution.

As for as photo sensors goes:

Rule 71 addresses outputs of the custom circuits. IE what you can & cannot connect then to.

Rule 53 address outputs of the breakout, which specifically allows connecting them to custom circuits. So connecting a photo sensor (custom circuit) to an output is allowed as long as you don't go over your power budget. (R69 & 42)

I generally don't quote the rules because I think it better to read them in their entirety & make your own conclusion rather than rely on my interpretation.