For the last few years our team has been using spikes to control our solenoids, allowing us to actuate our pistons. This year, however, we are using 7(!) pistons and finding room on our electronics board for all those spikes has become a nightmare.
We’ve read that it is possible to drive solenoids directly from the pneumatics bumper, but so far we have had no luck in getting that to work. We’ve tried connecting both the festo valves (pre 2010 versions) and the SMC solenoids, but neither of those has worked so far.
The lights on the bumper and on the solenoids themselves are flashing when we expect them to, and the solenoids are making a faint clicking sound whenever we try to actuate them, but the attached pistons are not moving. These same pistons fire just fine when we attach them to our old set up (using SMC solenoids connected with spikes), but not when connected to our new set up through the solenoid bumper.
Here is a picture of the code we’re currently using to try to actuate the pistons. This includes code for an SMC double solenoid and a Festo single solenoid (note that I just copied this picture from a tutorial, in our actual code the names do not overlap): http://dl.dropbox.com/u/6411204/code.bmp
I am somewhat concerned that our old code uses numbers to actuate the solenoids while the new code uses booleans…
Our current knowledge all comes from this site: http://www.team358.org/files/pneumatic/. This site looks like an awesome resource, but unfortunately it hasn’t helped us solve this particular problem (yet).
Has anyone encounterred a similar problem? Any insights? We really don’t have room for these spikes, but if we can’t figure this out in the next few hours we’re going to have to go with them.
It sounds like your new solenoid valves might have 24 volt coils, and you’re trying to power them from a solenoid breakout connected to 12 volts. Double-check the voltage requirements. If they are indeed 24 volt parts, you can power the solenoid breakout from the Power Distribution board’s cRIO power supply, as specified in <R38> A.
I am somewhat concerned that our old code uses numbers to actuate the solenoids while the new code uses booleans…
You should be concerned. Those little red dots on the input to some of the LabVIEW functions are telling you that what you’re providing isn’t what the function expects. The Relay Set vi wants to see an “enumerated value”. The numbers work because "enum"s are actually numbers behind the scenes, but there’s lots of room for error when you do that. By right-clicking on the input to the function and choosing the “Create Constant” command, you will place a constant of the proper type.
Most of solenoids we’re using have 12VDC written on them. I think most if not all of them are more than two years old, and I thought the 24v solenoids were only introduced in 2010. I also thought the 24v ones were shaped like rectangles and were hard to get mixed in.
If I try setting them to 24v anyway, what would happen? Catastrophic things? (I’m not at all planning to try this, but I am curious).
Anyway, thanks for your help. We’ve resolved to put the spikes on the robot for tomorrow, but I’ll definitely be looking at this problem again in the future. It would be a good tool to have for next year.