Implement switching circuit in labview

[Dennis_Knutson]

You seem to be asking the same question as at http://forums.ni.com/t5/LabVIEW/interfacing-labview-with-relays/m-p/2783076.

You got very good advice there but seem to have ignored it. You seem to lack basic knowledge of GPIB and what it's necessary to use that type of interface. Your circuit is completely lacking in any control interface for the relays so it appears you are also confused by the electronics.

[pratheek]

Norbert_B  

I think I am not gud at explaining my problem. I am using Relays and I want to control the relays with NI USB-6501 which is digital I/O interface device that is used for data acquisition and control. It is compatable with labview. I would like to program in labview to control these relays using USB-6501. I would like to know how can i do it......

Regards

Pratheek

[Dennis_Knutson]

Please start with studying the fundamentals of DAQmx. There are several tutorials available if you just do a search. Search the DAQmx examples that come with LabVIEW. Search the forum for examples of relay control. As has been noted already to you, a buffer to drive the relays will probably be necessary. Your schematic does NOT show any interface to the relay coils themselves so providing any details is impossible. You should also know that there are test panels in MAX that allow you set the digital lines of the 6501 when you have actually defined the physical connections between the pc and your custom board.

[billko]

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@Norbert_B wrote:

Pratheek,

in order for the switch to work, it has to be supplied with power. Right?

But simply providing power doesn't switch it. Right?

So there must be an interface for the switch (is it a relay? Some kind of FET?) which CONTROLS the switch and let it switch to the next connection. You have to figure out if THAT INTERFACE is compatible to THE HARDWARE you already have available. If so, connect it. If not, build some kind of adoption board.

So currently this is no software related question!

Norbert

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Norbert - I saw that clip in your sig.  It was too uncomfortably close to the truth.

[Christoph_D]

Hi Pratheek,

perhaps there still is some misunderstanding among us. I hope I am getting closer to your point of view.

If you have a NI USB-6501, like you wrote before, you can theoretically use the digital output the control your switch, but you have to have a look at the specs of your device (e.g. page 17):

http://www.ni.com/pdf/manuals/371456h.pdf

But it would be your task to build a suitable interface the digital output can switch. If you have that interface you can switch your circuit in no time with LabVIEW with just controling the digital output.

If you use a GPIB it wont get any easier in my opinion since you would have to get a functioning GPIB device on top of your circuit.

LabVIEW and NI Hardware can only connect your hardware to your Computer/PXI System/cRIO ... etc. and provide you with possibilites to communicate or control your hardware for example over a bus like GPIB or directly over a analog or digital line.

What kind of communication protocol you would like to use is your decision eventually. You have to build the hardware you want to control/communicate with yourself. Anyone can just explain the pros and cons of your decision.

So my proposal is that you use a digital output to control your circuit. But you would have to build a matching circuit to the output levels of the digital IO device anyway.

I hope I could help you along, but feel free to further specify your question.

Kind Regards

Christoph

[pratheek]

Hi Christoph_D

Thanks alot. You exactly got my point of what I was asking for. I am trying to figure out  a suitable interface that could switch my digital output ...........I was asking for how could I control the Digital output using labview. May be i was not clear in explaing what i was lookig for but finally u got my point...........Thanks alot.....I will come back to you with my queries once I find the suitable interface

Regards

Pratheek

[pratheek]

Hi Christoph_D

Could you please tell me how could I switch my relays using Labview. I tried with the examples on relays in labview help but I am not getting any idea how should i use it for my project....... Could you please give me few suggestions or any example VI that could help me

Regards

Bhargava

[Dennis_Knutson]

You say you found some examples but don't mention exactly what ones and don't mention why you can't get any to work. You STILL have not provided any information at all on the exact interface to your board so how can you expect any more help from anyone here.

[pratheek]

Hi Dennis_Knutson

I am using USB-6501 for interfacing with my board. As its default configuration of the USB-6501 DIO ports is open-drain for 5 V i am using a pull-up resistor as a buffer to drive the relays. As far as i came to know the device is provided wit a software cd  to customize DAQ applications with NI LabVIEW....... and i have refered to relay switch example......

Regards

Pratheek

[Tirmizi]

some questions

is your NI USB-6501 detected by the MAX,

are you using DAQmx accessing the NI USB-6501. any success you got.  6501 is a DIO module and you can use its IOs for digital input and outputs. but from your cirucuit you  need a feedback control like sensing the analog signal and then switch the circuit accordingly via 6501. if this is so then you also need an analog measurement module to get the feedback and then you switch the relays via 6501 as per your req. will you control all the switches mentioned in your diagram