USB-6212 - Connecting Solenoid Valve and 3 wire PNP switches?

[benact]

Hello,

I need some help with connecting a pneumatic solenoid valve and a couple of 3 wire PNP switches to the USB-6212 because controls is not my specialty by any means.  I'll try and keep this concise and organized.

USB-6212 DAQ:

Main page: http://sine.ni.com/nips/cds/view/p/lang/en/nid/207096

Specs: http://sine.ni.com/ds/app/doc/p/id/ds-9/lang/en

1). Solenoid Valve: SMC, SYJ512-5WOZ-M5-F

   Important info: 24VDC, 0.35W power consumption

I was looking at this forum post:

http://forums.ni.com/t5/Multifunction-DAQ/usb-6210-for-24VDC-solenoid-valve/m-p/1045213/message-uid/...

and basically copied what they had there (see attached picture "Solenoid_Valve.bmp").  Two questions then:

   1: Would this work (are the resistors correct, are the connections correct, etc.)?  If not, how can I get it to work?

   2: What kind of MOSFET switch (or any switch/relay) would you recommend?

2). 3 wire PNP switches: SMC, D-M9PWVL

   Important info: 5, 12 or 24 VDC; 10mA or less current consumption

I looked here to see how to possibly connect the switches:

http://www.ni.com/gettingstarted/setuphardware/dataacquisition/digitalinput.htm

and again copied what they had there (see attached picture "PNP_Switch.bmp").  One question here:

   1: What would Vsup be on the USB-6212?  I'm almost thinking there's going to have to be another intermediate switch/relay/something between the 24VDC and the 5V connection on the DAQ, but I'm really unsure of this.

Of course, we'll have to have some kind of 24V power supply, but I think I don't have to worry about that until I figure out these conundrums.

Thanks for the help and patience with my lack of knowledge in advance.

--

Ben

[Wayne.C]

benact,

If I were doing this I would use a ULN2003 to act as the interface between your DAQ DO's and the solenoid valves.  This IC is readily available from many sources and very dependable.  Search the web for 'ULN2003 examples'. 

P.S.  Other feature of ULN2003 is the built in snubber diodes.  Should not need any other components other than 24V supply.

[benact]

Ok, thanks for the suggestion.  I did a little internet searching and it seems almost too easy.  I redid the "schematic" (see attached picture "Solenoid_Valve_2.JPG"), so I'm curious if I drew such a simple solution correctly.  Thanks again for the reply.

--
Ben

[benact]

Oops, I labeled the DAQ incorrectly.  The attached picture to this message was what I meant to post.

[Wayne.C]

benact,

No wrong connections, just one missing.  You need to connect pin 9 of the ULN2003 to the positive side of the 24V supply.  This allows the built in snubber diodes to do their job.  I've marked up your diagram accordingly.

One question I should have asked before is how long the wires will be between the ULN2003 and the solenoid valve?  If we're talking about a couple of feet then the builtin snubber diodes will work just fine.  If the wires are going to be longer, then I would consider installing the diodes directly across the terminals of the solenoid.

And yes ULN2003's make life very simple. 

P.S.  Kudos for doing your homework on the ULN2003.

[benact]

Thanks for the correction.  The wire length is, as of yet, undetermined, but I'll keep that in mind.

However, I talked with the project manager today, and he wants a relay/switch/solution that has terminals for lead wire and is preferably din-rail mountable.  I'm guessing that, since the ULN2003 is an IC, I'm not going to find a terminal-wire version, but I was wondering if there's something that's works very similarly, because he likes the idea of the simple and logical connections that the ULN2003 requires.  I'll be doing some googling for such a product, but if anyone knows of anything, that would be most welcome.

Also, we solved the issue with the PNP switches, so that no longer needs to be addressed.