voltage

[color sensor]

Hello Sirs/ Madam

I am a student at NCSU and I am a user of labview . I need some help in figuring out the code and the wiring diagram for integrating labview with my color sensor. Basically my sensor gives out a voltage when a threshold limit has been reached and I need to turn on another action ie generating a similar voltage when the threshold has been crossed. The device is digital.Hence I need a code which measures the voltage and once the threshold has been crossed it should give out another signal telling the device that the voltage has been crossed while displaying the voltages on the monitor.

Can someone please help me out here ?

Aditya Ram  

[Dennis_Knutson]

Before you can get any help with code, you need to provide information oh what type of device you are using to read the voltage. If it's an NI DAQ board, what type?

[color sensor]

hi

My DAQ is NI cDAQ 9172 and i am reading a digital signal from a color sensor. it gives out a signal once a limit which has been previously set has been crossed.please contact me if this doesnt help.

Aditya Ram  

[Dennis_Knutson]

No, it doesn't help much at all. The 9172 is a chassis for holding some actual data acquisition devices. By itself, the 9172 cannot measure anything.

If you ever determine what the actual DAQ device is, you should go to the DAQmx Getting Started page. DAQmx is the name of the driver for NI DAQ devices. There, you will get information on acquiring and sourcing different types of signals. There is a DAQ Assistant that can be to get quickly up and running.

[color sensor]

Hello Sir,

oh ok ,the board is a 9172 and the measuring  device is NI 9401. Does this help ? I heard this is what they use to measure digital signals.Thanks

Aditya Ram 

[Dennis_Knutson]

Yes, it is a digital I/O module. What your program would be doing is is looking for a digital 0 or 1 (whatever the sensor puts out when the threshold has been reached. This could be a simple while loop with a DAQ Assistant set for a digital read. The default output for the DAQ Assistant is a Boolean array I believe. You would index out element 0 and wire this to a case statement that does a write back to the sensor.

Since your acquisition device is digital, you cannot display the voltage that the sensor is seeing. The only thing you can display is the current logic level that the sensor outputs.

[color sensor]

Hello Sir,

COuld you tell me how to do the wiring connection on the NI 9401 module for a digital input?

A  

[Dennis_Knutson]

Here is the manual with pinouts and connection recomendations. You would need a female DB-25 connector to mate to the front. NI will sell you one (779104-01) or you can make your own.

[color sensor]

Hello Sir,

Thank you. I do have the female port required. I was wondering whether there was any way to configure the ports in labview so that as the signal is triggered there would be a way to display the signal on the laptop. Also since the signal triggered is of 13.8v and the labview digital consider 5 v as a high, will the board burn or get damaged?

Thank you.

A 

[Dennis_Knutson]

If your sensor does not output a ttl signal, you will have to convert it before connecting it to the 9401.

You write your progam to display what you read. It has nothing to do with configuring the port. Your program would be written to constantly read the digital input that you have connected the sensor to. You just need to create an indicator. If you are using a DAQmx Read that returns a Boolean, that is the type of indicator you could have.