real time measurement

[ago]

Hello guys

im agostino from italy and im studying biotechnology and so first of all i want to say: i dont understand very much of electronic 

but I try to wire my oxygen-sensor with the labview program on my pc

I wired my Sensor with banana-connector on a card (CB-68LP) and now i would wire with a buscable R6868 my card with a DAQ-Card and then wire the DAQ-Card with the pc (USB-connection). My sensor has a signal of 0.2volts

Finaly it should all be connected like in this picture here

http://www.elci.tuc.gr/images/monitoring.gif

And now my questions:

Did i made some wrong assumptions?

Can I with these method then see on labview my actual oxygen rate?

What type of DAQ-Card should i buy?

I hope some guys out there can help me becouse here in italy i didnt found someone who can help me

IM DESPEREDDDDDDDDDDDDDDD!!!!!!!!!!!!!!!!!!!!

GRETTS FROM ITALY TO ALL MY ELECTRONICFRIENDS

by the way: i wired the cable from my sensor with the card CB-68LP. does it care where i put my cable in the cable? http://digital.ni.com/public.nsf/websearch/5F6E0E5867D78C7D86256C4B007DB758/$FILE/CB-68LP.gif

when yes, how do i know in which pin i must wire my cable??

thank you all a lot

[Dippi]

Hi ago,

of course you can wire your oxygen-sensor with our DAQ devices and the CB-68LP.

What you have to do:
It depend on the device you want to have.
We have several devices.

USB Devices
- USB 6008/6009 (low cost)
- USB 6211, 6251, 6221, 6251, 6229, 6229 BNC, ......

With this USB devices you don't need the CB-68LP.

PCI Devices:
You can also buy so called M Series devices. This devices are PCI devices (6221, 6251, 6281, 6259,...).
If you want to use these devices, you need the CB-68LP.

For ALLE these devices there is ONLY ONE driver called: NI-DAQmx
You can download this driver here:
http://digital.ni.com/softlib.nsf/websearch/5FDB3A745C91D61C862573540054495F?opendocument&node=132060_US

After installing this driver there will be a new tool called "Measurement&Automation Explorer" (MAX)
With this tool, you can take a look at the PINS of your device.
See "Screenshot MAX.jpg"
(==> Next post, because only 3 attachments allowed)

Second possibility:
Take a look at the pdfs (attachment) -> device pinouts

I think, that a normal M Series device like the PCI-6221 device should be enough.
You must know how fast you want to sample (samplerate) your signal from the sensor.
And you have to know, how exact (resolution) you need (e.g. 16bit, or 18bit).

These two information should be enough to select a device of National Intruments.
If you need more informations about the different device go to:
www.ni.com -> upon right, there is a search control -> insert the name of the device, e.g. 6221

Hope this helps
Best regards
Dippi

[Dippi]

and here the Screenshot

[wsallamy]

Sorry if this is sent twice there was a problem in the network

Hello

I am using DAQ card 6221 M & SC 2345 (using 2 input & 1 output channel) integrated in a PXI with controller 8186, in a real time  project using LabView 8.0, the PXI as target and another laptop as host.

The problem is that the maximum sampling rate that I could reach without being late is 1500 sample per second, higher than that it is late uptill 3500 sample more than that there is no output and the late Boolean is not working.

Do you have any explanation for this, that card must give higher sampling rate.

Attached the real time project it is just for checking the maximum sampling rate.

Thanks,

Waleed

[Filippo_Persia]

Dear Wsallamy,

Looking at your code Target Single Rate Siso.vi looks like you are trying to realize some kind of control system with a synchronized single point Analog Input/Output operation.
The whole point is in the "single point " operation. It can't be done faster that 1 KHz or so because it involves the software time in the PC processor.
Real-Time means you can program software with a certain grade of determinism. It doesn't mean that your software application will suddenly perform at hardware speeds ( 1MHz or so ).

Your card can actually give you much higher sampling rate but not in Single Input/Ouput mode, you have to use buffered input/output.
In this scenario you won't be able to change analog ouput values according to your control algorithm at the AI pace, you'll be able to work in "chunks".Meaning the actual AI "chunk" can decide the next AO chunk.

Finally if your control algorithm have to work at MHz pace in a single point manner you'll need to change architecture moving towards FPGA.

Best Regards