Measuring impedance with AT-MIO-16E??

Hi to everyone,
I am starting my experience with Labview at the technical university and I have to "write" a program in Labview 6.1 that will use the NI AT-MIO-16E-10 board and will generate the signal to Analog Output, the signal will go through the chemical sensor and then through the Analog Input back into the board. And I have to measure the impedance of such a sensor. Maybe some of You had made such a thing and can help me. Right now I started learning how to work with Labview.
I would be very grateful for any response

Hi,
If I understood well, you want to measure a resistive sensor using your MIO board.
You are using you AO to feed the sensor, and want to measure resistance in your AI.
The Analog Inputs of the board you mention can only measure voltage, to convet a resistance into voltage we normally use a bridge circuit - check the following link: http://zone.ni.com/devzone/conceptd.nsf/webmain/C83E9B93DE714DB08625686600704DB1 - it's about strain gauges, but the principle is the same.
For software, seach on the LabVIEW examples for DAQ voltage measurements.
Hope this gets you started,
Paulo

Similar Messages

Data acquisition and generation with PCI-MIO-16E-4 card help!!!!

Hello,
I'm using a PCI-MIO-16E-4 card with labview7 (in using DAQmx)and I
would like to draw a frequency response.
My problem is: my program can run correctly in low frequency but, it
can't work correctly in high frequency (after 2KHz the signal is
false).
For verifying my program: I only try to generate and acquire a sweep
sine. I constate after 2KHz the sine I read dosn't resemble to a sine
I wrote.
Can you say me where is the problem?
Thank you.
Le Trong Thao.

"Dr. Imad" wrote in message news:<[email protected]>...
> my understanding is that you are generating a sine wave (on one of the
> anlogoutput channels) and you are trying to read the signal.
> Since you can verify the signal at low frequency, but not at high
> frequency, it looks like you should increase the scan rate of the data
> acquistion (if you can, set it to 10 times the signal frequency)
> You can also use an oscilloscope to verify the signal is what you
> really generated.
Thank you for your response.
I've tried to do it, and I've tried several other possibilities but it
doesn't work correctly.
In fact, I think the problem is in my program. Do you have a program
that works correctly? I f
ound examples in the help but they don't run
correctly.
Le Trong Thao.

Upgrade win98/LV4 to win2000/LV6: Speed problems with AT-MIO-16E

I found that in Windows 2000 with Labview 6 the readout rate of our AT-MIO-16E board drops to approx. 2.5 kHz max. (before approx. 11.5 kHz in Windows 98 with Labview 4 ) using the 'AI single scan' VI (see attached scheme for the readout routine). I don't know if this is due to Win2000 or due to the new NI-DAQ drivers, but for our timing-critical application this is unacceptable.
Are there any suggestions about how to accellerate the readout of the AT-MIO-16E board?
With best thanks,
Thomas Schultz
Attachments:
AT-MIO-16E_DAQ_example.bmp ‏161 KB

Hi Thomas,
Here is another idea I can give but will be of limited use in chasing it down.
Make sure the board is using DMA.
DMA is alot faster than CPU based data transfers.
Maybe durring the softeware conversion, the board got installed without DMA enabled.
Just an idea.
Ben
Ben Rayner
I am currently active on.. MainStream Preppers
Rayner's Ridge is under construction

Position encoder works with PCI-MIO-16E-4 but not with PCI-6062E, why?

I am using A BNC-2090 to connect Agilent HEDS-6540 position encoder to my PCI-6052E. The application works fine with my 12 bit NI card PCI-MIO-16E-4, But with the new card I get extra counts in my position. ex 1052 pulses when it is only supposed to be 1000 counts in a complete revolution. This setup still works great with the old card, meaning I can just plug into the other card and run the same app on the same computer, just a different device number. I have not been able to figure this out.

You might be seeing the affects of dithing with your signal. I'm not sure why it would be on one board, though not the other, one counter must be more sensitive. Anyway, dithering is caused by vibration or other outside forces that cause small glitches that add to the count total for the counter. There is a way around this, and that is to use a counte convertor. There is a page on this website that tells how to make one. The link is below. I would sugget trying this to see if it will fix the problem.
Brian
http://zone.ni.com/devzone/conceptd.nsf/2d17d611efb58b22862567a9006ffe76/6f25cba2cd73417786256869005e5fc3?OpenDocument

Need to use AT-MIO-16E-2 to write MX code for PCI-6221 M SERIES that is installed in another system

Hello to all,
My Systems:
System 1
PCI-6221 M series card
LabVIEW 7.1 Express
Code developed using MX environment
WinXP
System 2
AT-MIO-16E-2 Card
LabVIEW 7.1 Express
So far do not see MX as an option (ran "default" install with this card)
WinXP
Here is my issue and 2 questions:
I installed a PCI-6221 M series card in a customer's PC. I am running the newest versions of LabVIEW Express (7.1) with WinXP. I used the standard LabVIEW installation to develop their code on that PC, including the M-Series disk. They now have a running application that is not quite complete. That system is in a different state. I need to go there and update some code in a few days, and I would like to develop that code at home, then port it to their machine. I have another computer at home. On it is installed an AT-MIO-16E-2. I have so far ran the standard LabVIEW Express (7.1) development system installation. Of course LabVIEW is smart enough to sense what kind of card I have and installed the appropriate software for that card, which I believe means that MX is NOT installed.
MY QUESTIONS?
1. Can I use DAQmx with AT-MIO-16E-2 and then port the code (with minor modifications) to the other machine?
2. What do I need to manually install on my machine with the AT-MIO-16E-2 card to enable this?
I thought I read that you can run MX on older boards by installing a patch. But I also need to know what software to install from the LabVIEW disks.
Many thanks for all your help,
Max

Hi MaxMotion,
Your AT-MIO-16E-2 card is only supported in Traditional NI-DAQ. You can not use DAQmx with that card. When you installed NI-DAQ (7.2 or greater) DAQmx was installed on your machine. The DAQmx VI's should show up in LabVIEW in the "NI Measurements" pallette. You can develop your DAQmx application in the sense that you can build the block diagram. However, you will not be able to run your application on the AT board.
-Sal

How can I wire two PWM outputs of Accelerometer into PCI-MIO-16E boad with SC-2043-SG?

I have been using counter/timer pin since the accelerometer (ADXL202AE, Analog Device) provides about 550Hz PWM signal. The purpose of the project is:
- To acquire PWM signals with Full cycle(ms) and Posity duty cycle(ms) generated in Accelerometer.
- To convert the cycles into acceleration value.
By using counte/timer(GPCTR0_Source) and Trigger(Trig1) on SC-2043-SG board, the signal was obtained.
However, after converting the PWM signal to acceleration value and plotting with labview on-line, the sampling rate was pretty low (26-28samples/sec).
Then, I began to doubt that there is a wrong wire connection. Even though I am using one counter/timer pin, the sampling rate
was low. The purpose of using the acceleration was to obtain two output using two counter/timer pins.
Could anyone help me wire pins and solve the problem?
GINO.

Gino,
You should definitely be getting many more values in your buffer. You should actually be getting 500,000 values every second because a measurement is being taken for every pulse. I found a couple knowledgebases that describe error -10920 and how to remedy it. One is pasted below and the other can be found through the link.
But I'm not sure if you're going to be able to fix this problem because you're measuring pulses at a very high rate. What is happening is every time a pulse width measurement is taken it is put into an onboard (DAQ board) FIFO buffer that is 9 samples long. The computer then reads these samples out of the FIFO and into an a buffer that you can see in LabVIEW. I think the FIFO is filling up too fast and the computer is not able to read the data out fast enough. Therefore you are losing samples because they are being overwritten. This is all dependent on your system.
Here are some benchmarks for pulse measurements:
The following numbers were derived from a Gateway with 128 MB-RAM and an Athlon 700 for ONE counter of the PCI-6602. The number of counters you are using will affect these numbers.
Finite Buffer
Buff Period - 7.25 MHz
Buff Pulse Width - 7.25 MHz
Buff Semi-Period - 3.35 MHz
Continuous Buffer
Buff Period - 250 kHz
Buff Pulse Width - 250 kHz
Buff Semi-Period - 140 kHz
You should still be getting many more samples than 26 though. Try using this example with a very slow frequency pulse to make sure it operates correctly. Then start speeding up the pulse and determine when you get error -10920.
Here is an internal knowledgebase that may help you:
Title:
After Long Periods of Acquisition with AI and Counters, a -10920 Error Occurs
Problem:
A customer has a PCI-MIO-16E-4 and his application is acquiring analog input signals and performing event counting with the buffered event counting mode. The problem is that the buffered event counting is at some arbitrary amount of time (e.g., after 2 days) getting an error with the number -10920. The questions are:
1. Why is he getting this error?
2. Do you know how big the FIFO is for this buffered event counting?
3. When he shares a DMA channel with the floppy controller, how can we make sure they use separate DMA channels?
Solution :
Here are the answers to the above questions:
1. There is probably just some noise on the signal line coming in at some point. The STC is VERY sensitive, so if there is any fast glitching, it will attempt to transfer all of these. This can also happen if the signal does not ramp up fast enough, resulting in double-triggering in the middle region. Use a filter, or a Schmidt trigger*, to clean up the signals. Another suggestion is to use the PCI-6602 with filtering.
2. There is no FIFO used for the counters. The mMite has its own FIFO, but it is only about 9 samples long.
3. PCI does not "share" DMA channels. It may technically be the same DMA channel number, but this is just for reference. PCI cards use Bus Mastering. With Bus Mastering, the operating system gives up control of the PCI bus so that the hardware (in this case, our DAQ board) can handle its own data streaming, eliminating the extra step of having the OS monitor the transfers. The DMA channel numbers are just the "channels" that are supported by the mMite chip. You can have 3 PCI cards in the PC, each with DMA 1, 2, 3, and none of them will actually be sharing any resources.
And another knowledgebase about error -10920
http://digital.ni.com/public.nsf/websearch/8FB9091CB9BB452B8525642000554799?OpenDocument
Hopefully this all helps,
Erick D.
NI Applications Engineer

Pins at a PCI MIO-16E-1 to Measure Frequency(DAQ-STC).vi?

I want to measure frequency with the
"Measure Frequency(DAQ-STC).vi".
Can't find the appropriate connector pins
in the manual of my PCI MIO-16E-1.
Can someone confirm or correct me?
Signal - PFI1/GPCTR1_SOURCE
SignalGND - PFI9/GPCTR0_GATE
PFI8/GPCTR0_SOURCE - PFI4/GPCTR1_GATE
Thanks in advance
Manfred

Manfred,
You can find this information by going to the http://www.ni.com/manuals site and viewing the E-series manual. There is a table which shows the pin number, name, and function for each pin.
Pin 10 - PFI1/Trig2
Pin 11 - PFI0/Trig1
Pin 43 - PFI2/Convert
Pin 42 - PFI3/GPCTR1_Source
Pin 41 - PFI4/GPCTR1_Gate
Pin 40 - GPCTR1_out
Pin 6 - PFI5/Update
Pin 5 - PFI6/WFTRIG
Pin 3 - PFI9/GPCTR0_Gate
Pin 2 - GPCTR0_Out
Pin 4,39,35,36 - DGND
Mark

AT-MIO-16E-10 must work with Win XP computer w/o ISA slot using LV 7

DAQ cards were working in old computers in ISA slots under Win NT 4 /SP 5/ LabVIEW 5.1.
Now we need to make them work with new computers w/o ISA slots, Win XP Prof /SP 1 /LabVIEW 7.
How to reinstall old cards? And s/w?
Is any box to put AT-MIO-16E-10 and make connection to the new computer? As External units
How about old driver WinNT? and ability to run LV 7 Express programs?
We have good experience in our Tech College using DAQ Signal Accessory box as well as Connector box.

Hello,
I think I just responded to this same question via email. You should be expecting an email soon from service request number 7053969. If I'm mistaken by this, and you do in fact need a response to this forum posting, please post back.
Cheers,
Jared A

Is it possible to start a PCI4472 and a PCI-MIO-16E-1 simultaneously using an analog trigger (with pre-trigger)?

I would like to start several PCI 4472 and a PCI-MIO-16E-1 simultaneously. All boards are connected via a RTSI cable.
My program works fine if I use software trigger, or an analog trigger from a PCI4472 channel. However, the analog trigger works only when I set pre-trigger (or pre-scan) to 0.
Is it possible to start a PCI4472 and a PCI-MIO-16E-1 simultaneously using an analog trigger (with pre-trigger)?
Thanks.
Ian Ren

Hi, Bill
I think it is possible to set more than 38 pre-trigger scans on a single 4472 card. I've done this before. You can verify this by running the Labview example "Acquire N - Multi-Analog Hardware Trig.vi" which comes with LabView.
What I try to do but without success/luck so far is to start data acquisitions of several 4472 cards and a PCI-MIO-16E-1 card using an anlog trigger (with pre-trigger).
Thanks for your help.
Ian

Can i measure resistance with a PCI-MIO-16X-10

good day!
In my work we measure inflator resistance with an external ohmeter and switch selector, for now we're working in update this method of measure resistance. The program used to activate the inflators was built in labview 7.0 and use a GPIB and PCI-MIO-16X-10 boards only.
The question is if we can measure resistance with this board (PCI-MIO-16X-10), we can do it?
thanks for all...

Cordero,
Not directly but with some auxiliary circuit elements you can. To measure a resistance you need to know both the voltage and current associated with the resistor.
One way you can do this with a DAQ device is to create a voltage divider using a known external resistor. By measuring the voltage drops across both the known and unknown resistances, you can calculate the value of the unknown resistance. You can use the analog output or the board power supply as excitation voltage for the voltage divider. Use two analog input channels to measure the voltages across the resistors. As long as the values of the resistors are much lower than the input resistance of the analog input channels, you can get good results. The accuracy is limited by how well you know the value of the "known" resistor, the resistance of the inputs, and the accuracy of the A/D converter. The accuracy of the known resistor is probably the largest contributor to the overall error.
Lynn

Possible sampling rates of a PCI-MIO-16E-1 with DASYLab

Hello!
I'm using a PCI-MIO-16E-1 DAQ. It's maximum sample rate is 1.25MS/s
My questions:
- What does maximum output rate of 1MS/s mean? I need 3 channels at 400kS/s.
- What are the possible sample rates? Can I use e.g. 3 channels with 105 kS/s each?
- If not what are the fixed sample rates of that card?
Thanks a lot

Hi matadler,
The E-Series boards have one DAC for each output, therefore you can use the full output rate with all output channels.
The PCI-6070 (formerly known as PCI-MIO-16E-1) has 2 analog outputs, which can be used at up to 1 MS/s. If you need more analog outputs, you need another board.
Analog inputs on the E-Series boards are multiplexed. This means you have only one ADC which is used for all analog input channels. You have to divide the maximum sampling rate by the number of channels you actually use.
For your application, this means you can use up to 416kS/s with 3 channels. There are no fixed sample rates on the board, so it's no problem to use 105kS/S.
Regards,
Richard H.
National Instruments

Is the AT-MIO-16E-2 ISA card compatible with a Pentium III 1GHz with a 133MHz bus?

Is the AT-MIO-16E-2 ISA card compatible with a Pentium III 1GHz with a 133MHz bus? The system has an ISA slot available but I'm afraid the bus speed is too fast for this old card. Do I need to buy a new PCI card to work in this system?

Hello;
As long as your machine has a ISA slot and that the NI-DAQ driver is properly installed on it, you shouldn't have any problems with it.
Regards
Filipe A.
Applications Engineer
National Instruments

AT-MIO-16E-10 Read encoders problem (a possible driver problem ?)

Hi there! I have AT-MIO-16E-10 board and i have a problem with reading the "values" from an incremental encoder.Here it's the description of the problem : I have the encoder conected via a mechanism formed by a belt and a pulley (the pulley it is connected directly to the encoder shaft) and this mechanism it is moved by a dc motor which it's also conected to the belt by an identical pulley mounted on the dc motor shaft.The motor drives a cart (by this mechanism formed by pulley-belt) on a track which has 1200 mm length.Now here comes the problem : The resolution of the encoder i use to measure the position it's 10000 ppr. The diameter of the puley it's 30.56 mm. Now the pulses given by the encoder during the full track (the total counts measured within the total length of the track i.e 1200mm) are measured with an universal counter (a hardware device) and with an aplication program (which it is attached bellow).The number of pulses for the total lenght of the track it's around 125000 (plus minus maxium 10 pulses) for the universal counter device (the hardware device) and around 128000 for the aplication program (plus minus 100 pulses).Now if we do a simple mathematical calculation we shall observe the following : if the puley has the diameter of 30.56 mm that gives us a linear length (the length of the circle) of PI*diameter i.e around 96.00424 mm (3.1415*30.56).If the total length of the track it's 1200mm that means the puley makes 1200/96.00424 rotations i.e. around 12.499 rotations and if the encoder give us 10000 ppr that means 124990 pulses for the total length of the track (for 1200mm) which it's extremely closed to the value of 125000 pulses provided by the universal counter (the hardware device) and quite far from 128000 pulses provided by the aplications program attached bellow.If we supose that the corect number of pulses it's 128000 that means the pulley should turn 12.8 times comparing with 12.5 times on the total length of the track which it's not true! (i could see with my own eyes that the pulley rotates under 12.5 rotations during the total length of the track). So after my opinion there is something wrong with the software (the program it is downloaded from zone.ni.com).I'm using AT-MIO-16E-10 hardware device,with LV6.1 (and real-time version),NI-DAQ 6.9.3 driver on XP1600+ processor,with Windows XP operating system.If any of NI aplication engineers see this please reply as quick as possible.Thank you very much for reading this and i'll be waiting for your answers as quick as possible.Best regards,Michael.
Attachments:
Quad._Encoder_with_E-series_(STC).VI ‏50 KB

>by Michael Antonios
The number of pulses for the total lenght of the track it's around 125000 (plus minus maxium 10 pulses) for the universal counter device (the hardware device) and around 128000 for the aplication program (plus minus 100 pulses).
>mross
IF the signal from the encoder is correct (proper voltages High and Low, and noise free), THEN the count will be correct.
This is gauranteed.
You probably have a noise problem ( I speak from experience). The counter is expecting TTL logic. In my experience, if the low of the encoder signal has noise exceeding 0.8V, the counter will falsely count the noise.
The simplest solution could be to trigger on the falling edges of the encoder signal. There is more "headroom" coming dow
n with TTL. If your high signal is running 5V, the undefined range starts at 2.4V (which is pretty much when the counter will start counting). This gives you the ability to reject 2.6V of noise. On the rising edge, you may have a 0.3V low and only 0.5V of noise rejection.
The other option is to clean up the noise. Get an osilloscope and start looking. Fix any bad grounding and wiring practices. Turn off any noisy equipment. There are ways to buffer the counter input so that the encoder signal is a differential signal. Optocouplers and schmitt triggers can clean up the encoder signals. Sometimes the encoder needs to drive some current to be less noisy. A fast Line Receiver can clean up rounded off encoder pulses (see US Digital - $16).
Good luck,
mike

Quantization Error for NI AT-MIO-16E-2

Hi
I wanted to confirm the value of quantization error for the 12-bit NI AT-MIO-16E-2 DAQ. I can take values between -10 to 10 Volts. So the quanitization error would be:
= +/- 0.5*(20/(2^12)) = +/-2.44e-3
Is this correct? This seems like a high amount of error when voltages are below 0.1V
Also, I want to know if the above DAQ card comes with an anti-aliasing filter, depending on the sampling frequency.
Thank you
Karthik

Hi Karthik,
If you choose your measurement range to be +/-10V, the smallest change that can be detected is 20/2^12 = 4.8mV. So the maximum quantization error would be +/-4.8mV. If you're looking to increase the accuracy, you can change the measurement range to be the smallest possible for your requirements.
There's no anti-aliasing filter built in to the DAQ card, but you can easily implement them on a terminal block (analog) such as the SCB-68 or in software (e.g. Low Pass Filter in LabVIEW).
Analog Input Low Pass Filtering with an SCB-68 Terminal Block:
http://digital.ni.com/public.nsf/websearch/5D82A2990FB1D21386256EEE00018FF0?OpenDocument
Hope this helps!
Thanks,
Lesley Y.
Applications Engineering

Accurate time stamp PCI-MIO-16E-1

Hello,
I need measure analogue signal which is acquired after rising edge on TRIG1 is detected. It works well, but time stamp of the waveform's beginning is not very accurate. So I want to ask you about possibilities to increase time precision, because I need repeat this measurement with cca 600Hz frequency.
I have interest about resolution which can be obtained. I use LabView 7.1.
Thank you for soon answer.
Martin Stefik

Yes, you understand correctly. Each trigger need own precise time information (hh/mm/ss/ms) or better.
But, I'm not sure that I can acquire both triggered input (let's say AI0) and continuous input (say AI2) on one PCI-MIO-16E-1 card. If it is possible, can you write example for me? This idea is good. I tried to do something similar. But, I'm new in with labview so it stayed without success
Thanks

Measuring impedance with AT-MIO-16E??

Similar Messages

Maybe you are looking for