Change counter input USB-6211

Situation: I have 3 signals I want to measure using counters on my USB-6211. Since the 6211 only has 2 counters I was planning to measure them seperately and just switch which PFI was the input depending on which signal I wanted to measure. However, when running the VI only PFI0 and PFI2 detect anything. If I connect to any other PFI the Read times out.
From other forum posts and my Device routes in NI MAX it says I should be able to internally route PFI0-3 to any of the CTR inputs so what am I missing here?
Thanks!
Wyatt
Attachments:
basic counter example.vi ‏18 KB

This is no longer an issue. I copied the code into my main VI and created a new SubVI and it is now functioning properly... not sure what changed when I copied it though.

Similar Messages

Externally controlled counter direction with USB-6211

I am using a USB-6211 and created a simple read counter application with the DAQ Assistant. It counts pulses (1 sample on demand) on Counter 0 (PFI0). When I set Direction to Externally Contolled it does not work properly. It counts random up and down. According to the manual my direction input line is Ctr 0 B (PFI1), but the level of this pin has no effect. What am I doing wrong?

Hello Steffan,
According to the following Knowledge Base you have cannot use the default settings wehn trying to externaly control the direction of the counter:
http://digital.ni.com/public.nsf/allkb/1A8818274130FA388625722E00760CC9?OpenDocument
Since these changes cannot be done in the DAQ assistant you have to use the DAQmx API to resolve this. I have attached a small example that does a simple event count on the source pin of counter 0 (which is also the A input of the counter). With a property node I have set the Counter Direction input terminal to PFI 1 (which is the B input). Now when the PFI 1 is low you will count up, when it is high you will count down.
hope this helps,
Regards,
RikP - National Instruments Applications Engineering
Message Edited by RikP on 06-05-2008 10:12 AM
Rik Prins, CLD
Applications Engineering Specialist Northern Europe, National Instruments
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Attachments:
Count Digital Events Up-Down USB-621x.vi ‏33 KB

USB-6211 - Getting Error 50103 when attempting to use two counter method

I am using a USB-6211 and want to measure the speed of a motor by counting pulses coming back from sensors on the motor. Speed will vary from 0 to about 5k Hz.
My strategy is to use "Method 2" in the manual to measure using two counters. To do this I am attempting to generate pulses of known duration with Counter 0, route these pulses to the gate of Counter 1, send the motor pulses into the source of the counter1 and letting the counter determine and report the number of pulses that occur during the "gate time".
To get the pulse generator going at 8,333 Hz I do this:
AGniDAQmx_CreateTask(instrHandle,"TimingPulses, Task_Handle8)
AGniDAQmx_CreateCOPulseChanFreq(instrHandle, Task_Handle8,"Dev1/Ctr0","Out",DAQmx_Val_Hz,0,8.333,0.5)
AGniDAQmx_CfgImplicitTiming(instHandle, Task_Handle8, DAQmx_ValContStamps,1000)
AGniDAQmx_StartTask(instrHandle, Task_Handle8)
This works fine. (By the way, I do stop and clear the task before exiting.)
Now I add this code in a new task to try to use the Counter0 pulses to measure the input pulses with Counter1.
AGniDAQmx_CreateTask(instrHandle,"MotorPulses, Task_Handle5)
AGniDAQmx_CreateCIFreqChan(instrHandle,Task_Handle5,"Dev/ctr1",MotorPulses,0,10k,DAQmx_Val_Hz,DAQmx_Val_Rising,DAQmx_ValHighFreq2Ctr,0.12,10,"")
AGniDAQmx_ReadCounterScalarU32(instrHandle,Task_Handle5,10,E)
AGniDAQmx_ClearTask(instrHandle,Task_Handle5)
This function fails on the CreateCIFreqChan() call with an DAQMXError 50103.
Apparently Counter1 resources are being tied up by Counter0. Is this true?
Any suggestions?
Thanks,
-CBJohnson

Hi Mallori,
Thanks for the great reply message. I do appreciate your help.
Yes, I think you understand my application. The motor can turn from zero to about 5K RPM and one pulse is generated with each turn of the motor.
This application is using Agilent VEE but the statements are "C-like" so that's why I posted them like that. I can't "cut-and-paste" directly from the VEE statements and I have to type them.  I mis-typed the Implicit Timing statement. It was missing an "_". It should have been:
AGniDAQmx_CfgImplicitTiming(instrHandle,Task_Handle8,DAQmx_Val_ContStamps,1000)
I think I understand what you are saying about DAQmx_Val_HighFreq2Ctr using the resources from both counters That explains why I get the message about resources not being available.
I have tried to use Counter Method 1 and it *almost* worked.  A problem comes about when the motor speed is zero (stopped) and, since these motor pulses are being fed into the Gate of the counter, the zero value makes it simply time out. Increasing the timeout value to infinite (-1) makes the entire program hang. I need it to go on -- looking for other user input, reporting other data being collected, etc. If the counter is waiting for the Gate signal to rise to start counting and to drop to stop counting and do the calculation, it will not work since it just times out.  I went to this counter method (actually called counter method 3 in the DAQ manual) because then I am trying to generate the pulses of known period and send these pulses to the Gate.  Then I am feeding my pulses into the Source of the counter and letting it determine how many pulses occured during the "gate time". In this case, zero pulses during the "gate time" should be OK; it should simply report that zero pulses were detected and start counting again on the next rise of the Gate pulse.  I thought I could simpy adjust the length the "gate time" to measure my range of frequencies.
Make sense? Any way to do this with the two counters of the USB-6211?
Thanks, Mallori,
-Craig

USB 6211 DAQ counter

I am using the circuit and labview program found on the following link and I would like to use a USB 6211 DAQ. I have noticed that the ctr0 and ctr1 both have multiple pins on the DAQ. The circuit diagram says to connect one to "out" and the other to "gate". Do I have to initialize anything or declare what pin i am using, or can i just wire to the "out" and "gate" pins for the respective counters and run the program?
http://decibel.ni.com/content/docs/DOC-8665

Hey,
At the DAQmx Create Channel.vi you declare what counter you are using with the Physical Channel Input.
E.g. you specify Dev1/ctr0 then you have to take CTR0 Out or Gate or Source, depending on the Task.
Christian

How to use voltage signals as input signals into USB-6211

Hello everyone,
I have a USB-6211 and a PDQ80A -quadrant photo detectot from thorlabs, i am trying to take three voltage signals from the PDQ80A into my PC using USB-6211 from NI. THese voltage signals are X,Y and sum (X+Y).
Looking forward to your reply.
Thanks in advance,
_Perseus

Technically, the question was in the title. But of course, the answer to that is... Connect them using WIRES. It's designed for voltage signals, just wire your cell outputs to whatever DAQ input channels you're going to read.
Using LabVIEW: 7.1.1, 8.5.1 & 2013

USB 6211 Counter

Hi. Does anyone know how I can drive a 0-12V PWM device with the 6211? How can I control the frequency of the pulse?
Thanks!

Hi Seascan,
What type of application are you working with in regards to PWM and this device? The 6211 does not support hardware timing, therefore the duty cycle/frequency will update as fast as the processor can handle or execute. There was a similar question on using PWM with the USB-6211 on a previous forum. Have a look at it here and if you have any further questions please let me know.
http://forums.ni.com/t5/Counter-Timer/NI-DAQmx-M-Series-Pulse-Width-Modulation-PWM-not-working-with/...
Regards,
Ben N.
Applications Engineering
ni.com/support

How to measure frequency by USB 6211?

Dear all,
I'm using USB 6211 to measure the input analog voltage signal, then use a counter to yield the frequency. Please find the VI figure in the attachement.
The problem is the insteal of measure the right frequency, which is from 300Hz to 1000Hz. There is a lot of high frequency noise from thousand to milliion Hz. I think it pick up the high frequency harmonics. How to avoid it or use a more effective way to achieve the measurements.
Regards,
Alan
Attachments:
flow rate frequency measurement.JPG ‏43 KB

You have to suppress high frequencies on the analog side of your signal. You must set it to a frequency which is not higher than half of your aquisition rate. If you sample with 10 kHz your filter must have a cutoff frequency of max. 5 kHz. Otherwise you will see the signal mirrored at the half of the sample rate. A 6kHz signal will lead to a 4 kHz signal after the sampling.
Waldemar
Using 7.1.1, 8.5.1, 8.6.1, 2009 on XP and RT
Don't forget to give Kudos to good answers and/or questions

How to make ROD426 connected to USB-6211 work in Labview

Hello
I have a rotary encoder type Hadenhein ROD426 connected to a USB-6211 I/O modul.
I need to make this work in Labview, so i can read the position for the rotary encoder by angle. I can't find anny tools in Labview that does this.
Does annyone have anny tips?
Gøran Steen

Gsteen,
There are some examples in LabVIEW's Example Finder (Help menu -> Find Examples...) that might help. Try Hardware Input and Output -> DAQmx -> Counter Measurements -> Position. These examples are usually a great place to start. I looked at "Meas Angular Position-Buffered-Finite-Ext Clk.vi" which looks like it may be of help to you. You can also limit the example finder to only find examples that pertain to your hardware (USB-6211) by configuring the "Hardware" dropdown in the lower left-hand corner of the example finder. If you are browsing, check the "Requirements" list in the lower right-hand to see if a particular example works with your DAQ.
-cb

Route multiple 6602 counter inputs to one counter output...

Hi!
I´d like to route 4 different ttl signals, that are read by 4 different counter inputs to one single output channel (e.g. the output of one of the counters used) using pulse train generation with a divider of 4. Note that only one of the four inputs is active at the same time, to prevent overlay.
How can I do that with Traditional-DAQ?
Setup would look like this on the SCB-68
TTL1 ----o in0 (ct0)----o out0 TTL(1..4)/4 [Hz]
|
TTL2 ----o in1 -- (output of ct2 is redirected ro ct1)
|
TTL3 ----o in2 --
|
TTL4 ----o in3 (ct3)--
May it be better to just output each counter input signal at it´s own output and connect these outputs to one free I/O-pin hardwired?
Best regards
Zorniki

In the end I configured a counter for Pulse Train generation and opted to change the duty cycle and frequency via 'DAQmxWriteCtrFreqScalar" (i.e. Pulse Width Modulation)
I registered a callback for the 'DAQmx_Val_CounterOutputEvent' and then changed the dutycycle and frequency in that callback.
Unfortunately, I kept getting "The pulse generation with previous property settings must complete a
full cycle before the property can be updated." error messages and, opon further reading, managed to find a doc where National Instruments suggest adding a 'Wait(period)' before executing the 'DAQmxWriteCtrFreqScalar' call.
The problem with this solution is that it one has to wait a minimum of 2 Periods before the Pulse Train can be modified which is not acceptable for our work.
So is there an alternative solution which allows us to change the Pulse Train after only 1 Period ? Is there an event we can trap which allows us alter the Pulse Train after every period ? I'm sure PWM must be possible on Daq cards (PCI-6602 or PCI-6281 or PCI-6259)?
Cheers, Shaun.

How to send TTL output AND acquire AI voltage data using USB-6211

Hello,
I am relatively new to Labview, so please bear with me. I have a research application involving 2 pressure transducers and a high-speed camera. I wish to acquire analog voltage data from the 2 pressure transducers. However, at the start of the acquisition, I will need to send a single TTL output to trigger the camera. This TTL pulse must be sent out at exactly the same time that the AI acquisition begins, in order to ensure that my 2 pressure measurements and camera images are 'synchronized' in time.
Is this possible on the USB-6211 running with LabView 8.20? I currently have a fairly simple LabVIEW vi that uses a software trigger to start an AI acquisition - I have attached it with hopes that it may help anyone willing to assist me. I would prefer to be able to simply add something to it so that it will output a TTL pulse at the start of the acquisition.
Thank you in advance.
Regards, Larry
Message Edited by Larry_6211 on 12-19-2008 11:24 AM
Attachments:
USB6211_v1.vi ‏212 KB

Hi All,
I'd like to clear a few things up. First, you'll find that if you try to set the delay from ai start trigger and delay from ai sample clock to 0, you'll get an error. Due to hardware synchronization and delays, the min you can set is two. Note that when I say two, I am referring to two tick of the AI Sample clock timebase, which for most acquisitions is the 20MHz timebase. I modified a shipping example so you can play around with those delays if you want to - I find that exporting the signals and looking at them with a scope helps me visualize what is going on. The Manual has some good timing diagrams as well but it looks like you've already hit that. The defaults would give you a delay of 250ns from the start trigger - is this too high for your situation? What is an acceptable delay? I tend to think that "exactly the same time" is a measure of how precise rather than an absolute (think delays in cable length making a difference.)
With all that in mind, I see a few options:
Start your camera off of the AI start trigger (an internal signal) and just know it is 250 ns before your first convert.
Export the convert clock to use as a trigger. This assumes your camera can ignore the next set of convert clocks.
More complicated option: Internally you have an ai start trigger, sample clock and convert clock. From your start trigger to the first convert is 250ns but if you export your convert clock you're going to get future convert clocks as well. One option would be to generate a single triggered pulse using a counter (start with the Gen Dig Pulse-Dig Start.vi example) with the AI start trigger as the trigger for the counter, an initial delay of 250 ns, and a high time of whatever you want it to be. This should give you a singe pulse at very close to same time (on the order of path delays) as your first convert clock.
Hope this helps,
Andrew S
MIO DAQ Product Support Engineer
Getting Started with NI-DAQmx
Measurement Fundamentals
Attachments:
Acq&Graph Voltage-Int Clk.vi ‏37 KB

Counter input problem

hi, i'm using a counter input to count the falling edges of a digital pulse. I need to convert this into a time based measurement (period/frequency), but am having a litle trouble doing this. If any one can help? i'd prefer it if it were as simple as possible, i.e. no fancy programming as I'm new to LabVIEW and would like to fully understand what i'm looking at!
Many thanks in advance!
tom

Hi
What version of LabVIEW are you using? If you're programming with version 7.0 or higher you can configure your counter for period or frequency measurements quite easily using the DAQ Assistant.
Just drop down the DAQ Assistant Express VI. The Wizard that opens will ask you to choose your input type. Choose Counter Input and it list options for Edge Counting, Frequency and Period Measurement. Choose the one you want then choose the counter with which to do the measurement. When you click Finish a configuration dialog box will open up for you to configure the Input Range, the Task Timing, etc. There will also be some further information in the help section along the right of the window. When you click OK the DAQ Assistant will build your code.
I've attached a Zip file with 2 labview programs to demonstrate this. (They're written in version 8). Connect DIO 0 to PFI 9 of your DAQ card (I'm using an M Series card. If you're using a different card let me know). Extract and run both files. The Digital Output VI generates an alternating high and low signal for each iteration of the loop. The Counter Frequency Measurement VI measures the frequency of this output. The frequency is determined my the Wait Until Next ms Multiple function so change the input to that to vary the frequency.
Let me know how you get on with that and if you require more info.
Good luck!
SarahB
NI | UK
Sarah
Applications Engineer | National Instruments | UK & Ireland
Attachments:
Frequency Measurements.zip ‏65 KB

How to output the digital clock and synchronization signal from the NI USB-6211

Hello,
I need to connect the NI USB-6211 to control a digital to analog convertor chip (AD5541). However, this chip requires three input signals :1) Clock input, 2) Logic input or a synchronization signal and 3) Signal Serial Data input (CS, SCLK, DIN).
how to output the digital clock and the synchronization signal from the NI USB-6211?

Hi SaberSaber,
You should be able to use the counters to generate a pulse train that could be used for clock and synch purposes.
Hope this helps. Let us know if you have more questions.
Dave C.
Applications Engineer
National Instruments

6251 Counter input signal

Hello,
I am acquiring pulses which are 0-5V with the counter of the PXI 6251. However, I would like to know if it is possible to acquire pulses that are, for example 0-12V or 0-24V without damage the device. In other words, which is the voltage range for the counter input in a PXI 6251?
thanking in advance,
CJMV

Hi,
You will not be able to use the counter directly but you can setup an analog level trigger for your signals. This will create a pulse that isTTL compatible for you everytime the signal crosses a particular level. Then you can route this into your counter and perform any counter measurements on it. An example is this is shown here where it sets up a level trigger to make frequency measurements.
Alternatively you can purchase an industrial strength digital I/O board such as the USB-6525 but this does not include a counter.
Please let me know if this works out for you.
Message Edited by Abhinav T on 07-06-2007 05:20 AM
Abhinav T.
Applications Engineering
National Instruments India
LabVIEW Introduction Course - Six Hours
Getting Started with NI-DAQmx
Measurement Fundamentals

Benchmarks for Buffered Counter Input with X-Series Devices

Hi,
Does anyone know the maximum transfer rate (using dma) for the x-series cards?
I'm looking for data simillar to the one in this link:
http://digital.ni.com/public.nsf/allkb/72A7E41EE5A8756A862571DA0076F1D7?OpenDocument
More specifically I want to know the transfer rate for the PCIe 6343.
Thank you,
Eyal
Solved!
Go to Solution.

I benchmarked 8MS/s on a single channel on a USB-6353 (should have similar performance to the USB-6356/66) with a buffered counter input task. This was only a 10 minute test on my Dell E6400 laptop ( Windows 7 32 bit, Dual core P8600, 4GB memory) so a sustained 24/7 rate is likely less. Also, I wasn't doing much with the data, just displaying it in an array. This is pretty much topping out USB streaming on this system (32MB/s) so I wouldn't expect to get higher. I wasn't running much else in the back ground (Explorer, Powerpoint, Lotus Notes) and CPU was at ~20%.
Hope this helps,
Andrew S
Getting Started with NI-DAQmx
Measurement Fundamentals

USB 6211

Hi,
Can I use USB -6211 to be like a relay to turn ON and OFF the signal? The signal ON/OFF should happen instantly like a relay, no ramping.
/Kawsy

Hi mnk,
The USB-6211 will not quite work like a relay as there is no way of physical disconnecting its pins. However, if you simply wish to output signals ON (5V) and OFF (0V), you can do so by simply writing the appropriate value on the pins. Since this is an analog output, there will be some ramping at a very fine level. The specifications claim that we have a 5V/us slew rate, but this can vary depending on what load you connect this to. Examples on how to write to your analog output channels can be found in our LabView shipping examples.
Hardware Input and Output >> DAQmx >> Analog Generation >> Voltage >> Gen Voltage Update.vi.
I hope this helps,
S_Hong
S_Hong
National Instruments
Applications Engineer

Change counter input USB-6211

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