-24V NPN
-24V NPN
(OP)
We work with PNP and NPN signals for robots. How do you detect a NPN -24v signal with a multimeter? With PNP we see 24v on the multimeter so we know we are getting the signal but NPN we see 0. I applogize for the simpilicity of this question but any help would be apprecitated.
Certified SolidWorks Associate
SW2009 X64 SP 5.1
Dell Precision T5500
Nvidia Quadro 4000
Xeon 2.27GHz Quad Core, 6GB RAM
XP Pro X64 SP2.0





RE: -24V NPN
RE: -24V NPN
Certified SolidWorks Associate
SW2009 X64 SP 5.1
Dell Precision T5500
Nvidia Quadro 4000
Xeon 2.27GHz Quad Core, 6GB RAM
XP Pro X64 SP2.0
RE: -24V NPN
Keith Cress
kcress - http://www.flaminsystems.com
RE: -24V NPN
Certified SolidWorks Associate
SW2009 X64 SP 5.1
Dell Precision T5500
Nvidia Quadro 4000
Xeon 2.27GHz Quad Core, 6GB RAM
XP Pro X64 SP2.0
RE: -24V NPN
If you can't be bothered to use a pull up resistor, then try putting the meter into continuity or diode check modes. Try both ways around (red/black) because meters can be designed either way.
I'd use a pull up resistor myself because it reflects the actual application of OC outputs. One could save an entire afternoon messing around...
RE: -24V NPN
Gunnar Englund
www.gke.org
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Half full - Half empty? I don't mind. It's what in it that counts.
RE: -24V NPN
Always 24V: You should see around 23-1/2V when the NPN output is active and you'll probably see something around 0.08V when the NPN output is not active. The exact values are based on your meter's internals. That's why I can't tell you exactly. It's not important anyway, as a bad NPN output will be markedly different from this description.
Keith Cress
kcress - http://www.flaminsystems.com
RE: -24V NPN
Certified SolidWorks Associate
SW2009 X64 SP 5.1
Dell Precision T5500
Nvidia Quadro 4000
Xeon 2.27GHz Quad Core, 6GB RAM
XP Pro X64 SP2.0
RE: -24V NPN
All voltages must be positive relative to the 0V.
Active PNP output connects the load to the power source voltage (+24V) and is called sourcing.
Active NPN output connects the load to 0V and is called sinking.
Both are subject to voltage drop on the output transistor, and will not be exactly 24V or 0V, but something like 20-22V and 1-3V correspondingly.