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viggy96
17-02-2016, 20:27
Does anyone know how to "lock" the position of a piston that is controlled by a 3-position SMC valve? I tried setting them to "kOff", but that doesn't seem to work. They just fully extend and retract, which is not what we want. Should I use 2 'Solenoid' objects as opposed to 'DoubleSolenoid' objects?

FrankJ
17-02-2016, 21:49
You need a closed center three position valve to "lock" the cylinder. Not a typical FRC valve which are two position. And to be legal, a way that vents the cylinder with the required vent vavle.

viggy96
18-02-2016, 01:20
You need a closed center three position valve to "lock" the cylinder. Not a typical FRC valve which are two position. And to be legal, a way that vents the cylinder with the required vent vavle.

I know, and I believe that is what we have. I just wanted to know how they were being controlled program-wise. I was under the impression that setting them to 'off' would close both sides of the valve, but apparently not.

FrankJ
18-02-2016, 05:14
Just having two soleniods on the valve does not make it 3 position. If it is, then both soleniods off sets center position. You never want to energise both solenoids at the same time. Do you have the full part number handy?

Two position dual solenoid valves stay in the last state energised. IE extended or retracted which is what you are describing?

viggy96
18-02-2016, 07:16
Just having two soleniods on the valve does not make it 3 position. If it is, then both soleniods off sets center position. You never want to energise both solenoids at the same time. Do you have the full part number handy?

Two position dual solenoid valves stay in the last state energised. IE extended or retracted which is what you are describing?
I have absolutely verified that the SMC valves that we have are 3 position. Do you know how to lock piston position in the programming (in Java) using these types of valves? The model number is: SY5320-6D-N7T.

P.S. The 'DoubleSolenoid' and 'Solenoid' I was referring to were Java objects.

FrankJ
18-02-2016, 07:34
Without knowing the what the actual valve is, I cannot give any advice on programming it.

On the physical side. If you cannot fully vent the pneumatics from the high pressure vent, your pneumatic system isn't FRC legal. Closed center three posittion valves tend to prevent that

viggy96
18-02-2016, 07:38
Without knowing the what the actual valve is, I cannot give any advice on programming it.

On the physical side. If you cannot fully vent the pneumatics from the high pressure vent, your pneumatic system isn't FRC legal. Closed center three posittion valves tend to prevent that
I gave the model number of the valve before, but here it is again: SY5320-6D-N7T. It is manufactured by SMC.

FrankJ
18-02-2016, 16:31
Silly my for try to read this on my phone. Anyway that does look like the part number for a 3 position valve. The valve should block the A&B ports & lock the cylinder when both solenoids (the physical ones) are de-energized. If not the valve isn't that part number or something else is wrong that programming will not fix. Another possibility is the cylinder is acting faster the valve. If so you will need flow restrictors in the cylinder ports.

You probably want to use two solenoid objects and set them both to off rather than the double solenoid object. The net result should be both solenoids off.