Digital inputs. PFI trigger inpurs

Hi,
I want to be able to to start the data acquistion by the use of digital tigger, say on the rising edge. Do i use the PFI inputs and if so how. Or can use one of the digital input channels. Any help would be grateful. Note that I am using NI PCI 6259 and labview 7.
Regards,
Tadhg

Using one of the PFI lines is actually a great idea.
For analog input, you could try the LabVIEW example VI, "Acq&Graph Voltage-Int Clk-Dig Start" you'll be able to get up and running quickly. You may select which line to trigger from using the controls under "Trigger Parameters".
If you are performing analog output, the "Gen Mult Updates-Int Clk-Dig Start" works in a similar way.

Similar Messages

Analog,digital and pfi triggering of PXI 6133 card

Hello,
i am using PXI-6133 card. i observed that there are three type of triggering options(i.e., analog, digital and PFI) available on each card. i want to know the difference? and also best one.
regards
chandu

Hi chandu,
Analog triggering is based on the value of an analog
signal. For example you can trigger when your analog signal goes above or below
a specified value. Digital triggering happens on a rising or falling edge of a
digital signal. For either type of triggering you must have a trigger source
that is the signal you are triggering on. For digital triggering on your card this
can be any PFI line. For analog tirggering it can be any analog input channel.
A detailed explanation of the triggering capabilities of your PXI-6133 can be
found in the S-Series User Manual. Triggering is discussed in Chapter 13. Also
a more great summary of triggering in general can be found in the Developer
Zone article, Tips and Techniques in Data
Acquisition Triggering - NI-DAQmx. What triggering is better depends on your
application and which one is more suited to your trigger signal. If you have a
digital trigger source then digital triggering will work great. If your trigger
source is an analog signal than you will probably need to use analog triggering.
Let me know if you have any questions and have a great weekend.
Thanks,
Nathan
National Instruments
Digital Hardware Engineer

NI-DAQ Digital Edge Start Trigger

Hi -
I have a digital input line that I would like to use as a trigger in order to collect 1 data sample of 31 analog input lines. How do I configure this task? I have been getting all kinds of error messages and am assuming there must be a simple way to go about it.
Thanks,
Dave

Hi Dave,
I think there is a problem either with your configuration files in MAX or the driver. Try renaming the MAX Data folder located at C:\Program Files\National Instruments\MAX. Also, you can try exporting your MAX configuration to preserve what you already have and then start fresh by creating new task. This will create a new MAX configuration and new Data folder when you create a brand new task.
I have searched for the -2147220733 error but I can't find any documentation on it even internally. Do you have another machine where you can try to create/test the task? Does the error appear in MAX or in LabView when you try to run your application? Do you have problem setting up tasks with any other cards in the computer? Does the error occur only when you have one channel in the task or all 31?
Selecting "1 sample HW timed" should definitely work.
Regards,
Natasa

Measuring Velocity with Digital Input

I am not very familiar with digital inputs and so am having trouble picturing this system. I will be starting from scratch but will have PXI chassis' available. I will have about 381 events. Event 1 will trigger acquisition, and over the next 10 - 20 ms, I need to capture the next 380 events. I don't need to know how long each event stays high, only the time in relation to the first event. I would like to catch any event that stays high for at least 1 microsecond.
Since it will require multiple chassis, I think I will just wire Event 1 to each chassis and so shouldn't have to worry about any syncing problems? A colleague has been looking at PXIe-6544 and 6545, but I'm not sure this is the right tool, and hoping there is a less costly alternative.
Hopefully someone can give me a kickstart in the right direction.

Hi Deskpilot,
If you're looking at separate lines, then my previous idea would not scale so well (each X Series card only has 4 counters). I like the idea of using an R Series board to do this and would suggest posting over at the Real Time Measurement and Control forum to double-check the feasibility.
If you had to do this with M/X Series boards, then the more efficient solution would be to use the Digital Inputs instead of counters. The R Series should be more elegant but I thought I would type up the suggestion for M/X Series anyway:
We have a few M/X Series Boards that have 32 clocked digital lines (48 digital lines total, but only 32 support HW timing). Depending on the board selection, you could sample the digital lines at 1 MHz (PXI 6224, PXIe 6323) or 10 MHz (PXI 6254, PXIe 6353). Then, in software you could determine which sample the rising edge occurs on and use this to timestamp when the event occurs. The two options would respectively give you 1us or 100 ns resolution.
The X Series (623x) cards have built-in timing and triggering for the digital lines. The M Series cards (622x) need to take in the clock from another source (you can use a Counter Output to create a 1 MHz or 10 MHz clock which can be triggered by your first event).
At 381 lines you'd require 12 boards. Each board requires 2 terminal blocks for access to all of the lines.
Again, I recommend looking into the R Series board for your task, I just wanted to post another solution in case somebody comes along with a similar issue but with a few less lines.
Best Regards,
John Passiak

Analog input generating trigger on the counter gate to measure frequency

Hello,
I want to measure a frequency on the analog input but it doesn't seem to work.
I'm trying to get it working using DAQmx with the use of ansi c.
The
first step I made was acquiring the information on the analog input.
With the use of a simulated device this shows a sine wave on the input.
My next step was to generate a trigger signal for the counter, but this doesn't seem to work.
I don't see how it is possible to connect the trigger on the analog input to the counter.
For the creation of the analog input and trigger I use the following code:
    DAQmxErrChk (DAQmxCreateTask("",&taskHandle));
    DAQmxErrChk (DAQmxCreateAIVoltageChan(taskHandle,"Dev1/ai0","",DAQmx_Val_Cfg_Default,-3.0,3.0,DAQmx_Val_Volts,NULL));
    DAQmxErrChk (DAQmxCfgSampClkTiming(taskHandle,"",10000.0,DAQmx_Val_Rising,DAQmx_Val_FiniteSamps,1000));
    DAQmxErrChk (DAQmxCfgAnlgEdgeStartTrig(taskHandle,"Dev1/ai0",DAQmx_Val_RisingSlope, 0));
For the creation of the counter I am using the following code:
DAQmxErrChk(DAQmxCreateCIFreqChan(taskHandle1,"Dev1/ctr1",
"",1,2000,DAQmx_Val_Hz ,DAQmx_Val_Rising ,DAQmx_Val_LowFreq1Ctr ,1,4,"");
I hope some one could give me a hint.
I have also tried the examples that come with DAQmx but far as I know this are only counter examples using digital inputs.
Thanks in advance.
Solved!
Go to Solution.

Hi,
You have to use the comparison event output to the counter input. Change this property after the configure channel function.
DAQmxSetChanAttribute (taskHandle1, "", DAQmx_CI_Freq_Term, Dev1/AnalogComparisonEvent);
Regards,
Bas

Usb 6009 digital input

Dear All!!
With the following vi. I'm trying to receive a 5V signal in a digital input, using a usb-6009 device.
I would like to use the 5 VCC supply, available in pin 31 of the same device and send it to pin 17, representing line0 of port0. During execution, 'm physically connecting and disconnecting these pins in order to see the difference in a led indicator. Unfortunatelly, the led is always on, even if both pins are disconnected.
Could somebody help me? I would be very pleased.
Thank you very much in advance,
Miren
Attachments:
proof.vi ‏38 KB

Hi Miren,
"the led is always on, even if both pins are disconnected"
RTFM?!
They use open collector inputs with an internal pullup resistor of 4.7k, so you actively have to pull down the input to GND to see a difference...
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome

How to acquire serial data on a digital input line with good performance?

Hello,
we have a performance problem with our realtime controller. Our objective is, to read a 24-bit long digital waveform from a digital input line. To do this, we supply a clock signal (236 KHz) to the PFI1 Line of our DAQ Board. On each rising edge of the clock, a new bit is set on the digital input DI0.
Our hardware which transmits the data, is triggered through a digital output from our realtime controller. On each edge on this output, the hardware starts a serial transmission of 24-Bits.
Everything works fine except the bad performance of our realtime controller. We want to acquire the 24-Bits in a 1ms timed loop. To measure performance we wrote a test program. In that, we only triggered the hardware and transfered the data to the realtime controller. The task which is doing this job, has a approx. CPU-Load of 30%, which is, in my humble opinion, very high. The task is not waiting for data or anything else! We have earlier implemented a control which is also using a 1ms timed loop. This control is sampling 2 analog input signals, 2 counters. Futhermore it's sending telegrams with CAN and doing many calculations. The strange thing is, this much huger program has a CPU-Load of 25%. Does anybody know where the problem is?
For the better understandig I attached our test-program to this text.
We're using:
PXI-8175 realtime controler
PXI-6221 Multifunction DAQ
Thanks!
Regards,
Crest!
Attachments:
dig_test.zip ‏51 KB

Hello,
First of all 30% CPU-Load is normal because the DAQmx-driver needs a lot of resources.
In your programm you should place a wait (for example with 1ms) into the while-loop which causes
lower CPU-Load.
If this is not enough you should build your vi like in the following example.
Regards,
Christian
Attachments:
Read Dig Port.vi ‏51 KB

How can i connect 24VDC to digital input (usb 6008)

hello,
how can i connect 24VDC to digital input (usb 6008), is it possible with some optocoupler?
thanks

The 6008 is a static DIO, so speed shouldn't be an issue. Therefore an optocoupler should work. Just make sure you get one the meets your specs.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines

Audigy 4 Pro digital input 16 - 24

I have a Sony MDS-JB920 minidisc deck hooked up to my Audigy 4 Pro through the external box. Works fine.
However, the Minidisc deck allows one to set both the digital input and output to either 6, 20 or 24 bit. As the Audigy 4 Pro is 24 bit, I've set the deck to 24 bit for both in and out. So far no problems. If I watch the settings panel whilst playing a minidisc however, it indicates that the signal coming from the MD deck is 6 bit, although the deck is set to supply 24 bit through the SPDIF out.
When I put the MD deck on rec mode whilst the PC is supplying audio feed, the MD deck loops it back to the SPDIF input of the Audigy and then the software does display 24 bit signal coming from the MD deck.
This is very confusing to me, does anyone have an explanation?

CMSS is an effect used for stereo sounds, to emulate surround sound for them. It has no effect on the DVDs you're playing as you're just outputting the AC3 signal so the speakers can decode it.
If you're using a digital connection, then CMSS will not have any effect for other sound either, you need to connect through multiple analog connections to get that sound. A standard digital connection (coaxial and optical SPDIF) can only pass over either a stereo PCM signal, or an encoded AC3 stream (like on your DVDs). Normal sound like music or games will only be passed over as stereo PCM, so there is no CMSS effect there.
If you can connect your amplifier through several analog connections, then you can use CMSS aswell, otherwise your amplifier might have it's own upmix option like ProLogic.
Cat

How to I connect Sourcing digital output from My Interface Board to NI USB 6501 channel configured as Digital input

When I connect an input to DI channel of USB 6501 card from my board which has sourcing Output t, iIn the Off state it is not pulled down properly. The volatge on the port in is 2.1V -2.5V based on the pull down resistor on my board. I suspect that it acts as a voltage divider.
The state on the card is still show as "HIGH "state, even my sourcing output driver has a pull down resister. when I use this interface board for PCI mseries devices it works fine. Do the pull down resister on my sourcing output is not worth. Is this because of pull up resister 4.7k inside USB card 6501.
USB 6501 specifications shows the Digital input accepts both source and sink modes. By default the card is in sourcing digital input mode. How do we can convert this in Sinkind digital input mode.
Could anyone Please give your suggestions to overcome this issue .
Thanks you.

You really should not have both a pull up and pull down on the same line. Really weird things can happen. If you insist on having a pull down on your board, then I highly recommend putting a digital buffer chip between the DAQ and your board.
Some boards with DIO have a pull up, while others have pull down. You just have to watch the specs.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines

I was given an assingment, but have no idea where to begin. The assingment is to create a text file using notepad with all of my digital inputs and some how make those imputs show up on my digital indicators on my control pannel

I was given an assingment, but have no idea where to begin. The assingment is to create a text file using notepad with all of my digital inputs and some how make those imputs show up on my digital indicators on my control pannel.
When it was explained to me it didn't sound to hard of a task, I have no LabVIEW experience and the tutortial sucks.

StevenD: FYI, I did NOT give you the one star rating. I would never do that!
StevenD wrote:
Ow. Someone is grumpy today.
Well, this is an assignment, so it is probably homework.
Why else would anyone give HIM such an assigment, after all he has no LabVIEW experience and the tutorials are too hard for him?
This would make no sense unless all of it was just covered in class!
This is not a free homework service with instant gratification.
OK! Let's do it step by step. I assume you already have a VI with the digital indicators.
"...but have no idea where to begin".
open notepad.
decide on a format, possibly one line per indicator.
type the document.
close notepad.
open LabVIEW.
Open the existing VI with all the indicators.
(are you still following?)
look at the diagram.
Who made the program?
Does the code make sense so far?
Is it a statemachine or just a bunch of crisscrossed wires?
Where do you want to add the file read?
How should the file be read (after pressing a read button, at the start of the program ,etc.)
See how far you get!
Message Edited by altenbach on 06-24-2008 11:23 AM
LabVIEW Champion . Do more with less code and in less time .

Triggering an event with a digital input

Hello all,
I'm writing my first Labview program. I used an architecture I found on the forums here, and it has been very helpful in getting me started. This architecture uses two while loops, one containing an event structure and one containing a case structure. (This is a queued state machine architecture, I believe).
Part way through the programming, we decided we needed a sensor to make sure the part was in the test fixture during the test. If the part is removed during the test, we'd like to safely stop the test. So basically, I need to monitor a digital input (on an NI-USB-6525 module) and enter the "Stop" case if the digital input turns off. I would also like to make sure this digital input is on before entering the "Start" case. I don't care if the input changes state when the test is not running, nor do I care about its state during the "Exit" case.
I'm really not sure how to add this functionality to my "stop" case. I don't even know if it's possible. I've been researching DAQmx events, but I haven't found an example or answer that aligns with my particular problem.
I've attached my code. It's incomplete right now - I still have a large number of steps to add. I wanted to get this issue figured out before I programmed any more steps. A preview of the code showing the basic architecture is shown in the picture below.
Does anyone have any ideas or suggestions for me, or questions if my problem is unclear? Also, if you see anything else in my code that will be problematic, please let me know.
Thanks in advance!
Attachments:
Main_Loop_072412.vi ‏195 KB

I should also add that I looked into event dynamic registration, but it seemed incompatible with my issue. I don't want my top loop to run only when an event triggers it - I want it to run all the time so that it can immediately respond to button presses. Also, most of the triggering I found was based on value change. I care about the actual value, not just that it changed.
I don't want to do anything that will bog the code down too much since it is important that the system respond immediately to inputs, especially to the stop or exit button presses.
I'm sure I am missing something very basic here. I'm used to ladder logic, where everything is simple and straightforward.

Digital Input Cannot Display this Video Mode Optimum Resolution 1280 x 1024 60hz.

HP Pavilion h8-1360t, Windows7 home premium 64-bit, AMD Radeon HD 7570 graphics card.
error message: Digital Input Cannot Display this Video Mode Optimum Resolution 1280 x 1024 60hz.
I get the error message as soon as Windows opens and the desktop displays. Then it goes black with that message. I've been using the computer for awhile and I had it so that when I maximized a window it would go across both screens. I have two monitors on the graphics card. Somehow I changed the settings so that a program would maximize to one monitor or the other. That is how I want it to work. Maybe I activated HydraVision. Now I have the problem when I start.
Also now when I boot to Safe Mode I get the message that there is no AMD graphics driver installed, or it is not functioning properly. I have tried to update it and the computer tells me I have the most recent version installed. I would like to uninstall it and reinstall it, but I'm a little worried I won't get it installed and be without video. Something like that happened to me once before years ago.
Could someone tell me what I should do please?
Thanks,
Jim Allen

HP support is here:
http://www8.hp.com/us/en/contact-hp/contact.html
In safe mode you should uninstall the driver, then try to boot normal again.
Then check if driver was installed by win7.
If not go go AMD website and download latest driver for your card.
V.
*** Say 'Thanks' with Kudos ***

Monitors with Digital Inputs

What monitors are available that accept the Toslink input directly? Do the keyboard and on-screen volume controls still work with this arrangement?

I believe Tannoy make a set of the Elipse range of speaker with digital inputs as well. I have no idea why you would want to do this though. I suspect the gains in quality would be tiny if anything at all. You'd be better to spend more money on something less techy and get something that really sounds great!

How can I use 4 DIO lines as digital input in a E series-SC 2050-ER8 set up ?

I have a DAQ system with an E series DAQ card that is connected to SC-2050 and ER8. I want to use 4 DIO lines (out of 8) for digital input. How can I do this?

Hello Suresh,
There are a variety of ways to accomplish this. If you are using LabVIEW, you will use the DIO Port Config VI and the DIO Port Read VI. You will use the line direction map input of the DIO Port Config VI to setup which 4 lines you want to be the input lines. The LabVIEW shipping example entitled 'Dig Multi-line Direction (E) VI' shows how to use the lines of the digital port on an E-Series device for input and output.
If you are using NI-DAQ function calls, you can use the Dig_Line_Config and Dig_In_Line calls to configure a digital line for input and then read from that line.
I hope this helps.
Regards,
Todd D.
NI Applications Engineer

Digital inputs. PFI trigger inpurs

Similar Messages

Maybe you are looking for