LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

Regarding Polarity: What is C V?

The power connector on the back of my USB-DAQ shows the letters C and V. 

is the C ground?  And V positive?

 

I don’t recall ever seeing a DC power connector labeled that way. 

FFA7AFA0-6AB9-4B21-B4E9-F5CF4930677A.jpeg

http://www.medicollector.com
0 Kudos
Message 1 of 13
(1,948 Views)
That's a good guess, I've heard common voltage used for ground.
0 Kudos
Message 2 of 13
(1,941 Views)

I would also guess the same C - Common/Gnd and V - Voltage??

 

What exact DAQ is that? I don't think it is NI, good to refer to the manual than blow up with reverse polarity.

Santhosh
Soliton Technologies

New to the forum? Please read community guidelines and how to ask smart questions

Only two ways to appreciate someone who spent their free time to reply/answer your question - give them Kudos or mark their reply as the answer/solution.

Finding it hard to source NI hardware? Try NI Trading Post
0 Kudos
Message 3 of 13
(1,922 Views)

It could be NI. It's they same type of connector you have on the cRIO, although there it is usually 4 pins for a redundant power supply connection. And it is labeled V1, C, V2, C on them too. As it is a keyed connector you should have no problems if you use the power supply that is delivered with the device. If you need to do your own cabling, basic electrotechnical knowledge is required and a look in the according manual will usually help.

 

This is for instance for the cRIO-9035. Take a look on page 8 for the explanation of the power connector. All NI devices have similar manuals which do describe such details pretty well. My only grasp with them is that they are usually very thin on more specific technical details about the device that are sometimes necessary to know to properly integrate a device in a bigger project. They are usually very careful to not specify too much, that may bite them if they have to change some internal component and such published but deemed unnecessary specs might suddenly change by that.

 

NI sells the according pluggable terminator block connectors usually too, in packs of 5 or 10, but if you have some other electronics distributor like Farnell, Mouser, RS Components or Digikey, you can buy them from them a lot cheaper. The manufacturer is either Phoenix Contacts, Molex, Weidmuller or Würth Electronics and sometimes some other ones. You need the 3.81 mm pitch variants. Weidmüller and Metz Connect are usually black like the NI ones, the others are green but work just as well.

Rolf Kalbermatter
My Blog
0 Kudos
Message 4 of 13
(1,886 Views)

See the

_____

—–—

Symbol to the right of the "11 - 30 V"?

 It indicates that internally the input is differential non-referenced.  

 

C is Common. The 11 - 30 indicates the range of potential so V is Positive w respect to common ( a -30 - -11) would require a negative input) 

C is Probably attached to 

Chassis through a largish restance

____

  \\\

And isolated from Earth Ground.

___

 —

  -


"Should be" isn't "Is" -Jay
0 Kudos
Message 5 of 13
(1,852 Views)

Use a meter and find out...

========================
=== Engineer Ambiguously ===
========================
0 Kudos
Message 6 of 13
(1,846 Views)

@RTSLVU wrote:

Use a meter and find out...


That just begs for users to remain uneducated about electrical symbols and is no substitute for RTFM! 😀


"Should be" isn't "Is" -Jay
Message 7 of 13
(1,843 Views)

@JÞB wrote:

@RTSLVU wrote:

Use a meter and find out...


That just begs for users to remain uneducated about electrical symbols and is no substitute for RTFM! 😀


Right but... What if the FM is not f'n available?😀

========================
=== Engineer Ambiguously ===
========================
Message 8 of 13
(1,827 Views)

Better GTFM then.  😄

Bill
CLD
(Mid-Level minion.)
My support system ensures that I don't look totally incompetent.
Proud to say that I've progressed beyond knowing just enough to be dangerous. I now know enough to know that I have no clue about anything at all.
Humble author of the CLAD Nugget.
Message 9 of 13
(1,822 Views)

@santo_13 wrote:

I would also guess the same C - Common/Gnd and V - Voltage??

 

What exact DAQ is that? I don't think it is NI, good to refer to the manual than blow up with reverse polarity.


It's definitely a NI DAQ.  See this manual:

 

https://www.ni.com/pdf/manuals/370784k.pdf

 

Look at page 20 (labeled 1-6 in the manual):

Kyle97330_0-1645654398098.png

 

I have one on the desk next to me.  No multimeter nearby though or I could actually check the pin output on the power supply.

 

0 Kudos
Message 10 of 13
(1,774 Views)