Half of pneumatics doesn't work

[Red Mage]

Okay, half the solenoids on our robot don't work. The compressor works and two out of four solenoids work. The wiring is identical for all solenoids and they are all coded the same. So when the non-functional solenoids should fire the corresponding lights on the Solenoid Module turn on but the solenoids don't change. When we hook them up to Spike Relays they work. Help would be appreciated. I'm willing to pay in hot dogs.

[MrForbes]

What solenoids are you using? There was only on in the KOP....are the others identical? source?

[Russ Beavis]

Keep in mind that the Solenoid Breakout is only a high-side driver (ie 12V across the leads or open) whereas the Spike is a full H-bridge (+12, open or -12V).

Maybe your valve is wired backwards and there is a diode that prevents current flow?

Russ

[Lord_Jeremy]

We are using the double-solenoid valves that were included in the kit of parts in previous years. (I believe they are made by SMC.) We are extremely sure that the valves are not wired backwards because we switched the connections for each solenoid across the various outputs on the Solenoid Breakout and only some of the outputs worked consistently. The other outputs appeared to never work at all, although their corresponding lights on the Solenoid Module would illuminate. We are toying with the idea that the Solenoid Module and/or Breakout is damaged. At this point we probably don't have time to get another Solenoid Breakout and Module so we moved the four non-working solenoid groups onto spike relays and are doing them the "old school" way. Is there a way to test out Solenoid Module and Breakout system? If one of these components are damaged, how can we get replacements and are they covered under any warranty? Are there any rules or regulations that would disallow the use of spike relays with the SMC double-solenoid pneumatics valves?

[Russ Beavis]

Do you have a schematic for your wiring? I'm not positive that you've properly split the 2 valves' windings across a pair of Solenoid Breakout outputs. When using a Spike, the winding pairs are spliced together and driven such that A or B or neither are energized and there are diodes in the windings that prevent them being energized simultaneously. When using the Solenoid Breakout, you'll need to wire A to one output and B to another and make sure that the polarity is correct (else the diode will not keep one of them from being energized).

Russ

[Lord_Jeremy]

Our wiring is such that Solenoid Breakout port 1 SIG goes to the positive terminal of side A of the valve and port 1 (-) goes to the negative terminal of side A of the valve. Port 2 SIG goes to the positive terminal of side B of the valve and port 2 (-) goes to the negative terminal of side B of the valve. This is repeated for the three additional valves of the same type.

[Russ Beavis]

You might want to swap the connections for the B windings. It's too coincidental that half of the windings aren't being energized but the NI 9472 LEDs are lighting up.

Russ

[Lord_Jeremy]

It wasn't a matter of only the B lines not functioning. Only outputs 2, 3, 6, and 8 appear to be functioning. What we've done now is wired two of the valves on those working ports and put the other two on 2 pairs of spike relays.

[EricVanWyk]

Can you verify that the lights on the cRIO module are lighting up as you would expect? Can you verify that the voltage across the valves are what you would expect?

Can you post your code?

Thanks

[krankin]

The solenoids from past years have come configured for 24V and then FIRST sends us the part to change it to 12 volts. I am not certain what voltage the cRIO puts out but you might want to check to be certain that your solenoids are configured to the correct voltage. The voltage that the solenoid uses is written on the side of the part that you plug the wires into.

[Russ Beavis]

I noticed that only 1 of your nonfunctional valves is a "B" half. My hot dog is still on the diodes that are in the double-acting solenoid.

Did you try moving the 1, 4, 5 and 7 "valves" to the 2, 3, 6 and 8 positions?

The NI modules are almost bulletproof and the Solenoid Breakout is stupid simple. I'd be really surprised if the LEDs for the 1, 4, 5 and 7 positions lit but you didn't get voltage to the valve.

Russ