I want to operate my 3 6036E DAQ cards in a master slave arraingment

I would like to resolve some timming issues by configuring my 3 6036E daq boards in a master slave arraingement. I have installed a RTSI cable on the boards.

Chris,
One thing to remember when synchronizing multiple boards is that you want to have a start trigger in addition to routing the sample clock over the RTSI bus (examples are available in the Example Code Library [http://www.ni.com/devzone/dev_exchange/ex_search.htm] and the NI Example Finder). Here are two examples (the first uses Traditional NI-DAQ and the second NI-DAQmx):
1. http://sine.ni.com/apps/we/niepd_web_display.DISPLAY_EPD4?p_guid=B45EACE3E13D56A4E034080020E74861&p_node=DZ52336&p_submitted=N&p_rank=&p_answer=&p_source=External
2. From inside LabVIEW go to Help > Find Examples to bring up the NI Example Finder. Inside the NI Example Finder browse to Hardware Input and Output > DAQmx > Synchronization > Multi-Device > Multi-Device Synch - Share
d Timebase & Ext Dig Trigger.vi
Also realize that these aren't simultaneously sampling boards (S Series), so each channel sample on an individual board will be separated by a small interchannel delay. Depending on whether you are working Traditional NI-DAQ or NI-DAQmx (http://digital.ni.com/public.nsf/websearch/42484E84DA98053686256D32006E0494?OpenDocument) this interchannel delay is different.
Ames
Applications Engineering
National Instrument

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Data-acquisition with NI 6036E DAQ card & GPIB using an external trigger

Hi all,
I hope somebody could give me some help with the following and answer some questions:
Simple system description:
Labview 6.1
PCI-GPIB card
6036E DAQ card
In my system, I am using an external analog trigger signal (A) for continuous data-acquisition. Characteristics of the analog trigger signal (A) are: ~40 Hz, signal height +1.48V, triggered by rising edge (the analog trigger signal (A) could be changed to a TTL signal). Each data-acquisition is done within ~1.0 ms after the rising edge of the trigger pulse. The timing of the data-acquisition and analyzing procedure is controlled by execution in a sequence structure placed in a loop.
Now, I connected a power meter to the system, to measure the laser power during the data-acquisition. The power meter has two options to provide the laser power data:
a) via analog signal output (voltage corresponds to laser power in watts)
b) via GPIB (direct output reading of laser power in watts).
Problem:
During a certain point in my data-acquisition sequence structure (defined by a frame), I want to use the next occuring analog trigger signal (A) to acquire 1 value from the power meter.
How do I do this in Labview programming for the following two situations?
a) If I connect the analog output from the power meter to an analog input channel of the 6036E DAQ card. The analog trigger (A) would be connected to a second analog input channel (In case the analog trigger signal (A) is changed to a TTL signal it would be connected to the PFI0/Trig input pin on the DAQ card).
b) If I use the GPIB connection of the power meter. The analog trigger (A) would be connected to a second analog input channel (In case the analog trigger signal (A) is changed to a TTL signal it would be connected to the PFI0/Trig input pin on the DAQ card).
An other possibility would be to trigger the power meter directly, so it outputs constantly power meter values at ~40 Hz. How could I than acquire 1 power meter value (at a certain time im my sequence structure) via analog input at DAQ card or GPIB?
Additional questions:
How do I configure the PFI0/Trig pin on the 6036E DAQ board individually as an INPUT?
How do I use an analog trigger signal (A) as counting signal for a loop, or as an activation signal for a sequence structure which includes GPIB commands?
It would be very nice if somebody could give me some help.
Kind regards,
beam

Hi beam,
I just want to verify that I understand your situation correctly:
An external trigger signal (A) is wired to one of your input channels (e.g. CH0) to trigger data acquisition of a second channel (e.g. CH1). Your power meter is connected to an analog input channel, which you would like to trigger with a certain rising edge at some of your sequence structure.
Problem:
During a certain point in my data-acquisition sequence structure (defined by a frame), I want to use the next occuring analog trigger signal (A) to acquire 1 value from the power meter.
How do I do this in Labview programming for the following two situations?
a) If I connect the analog output from the power meter to an analog input channel of the 6036E DAQ card. The analog trigger (A) would be connected to a second analog input channel (In case the analog trigger signal (A) is changed to a TTL signal it would be connected to the PFI0/Trig input pin on the DAQ card).
If a task has been configured to acquire signal from one analog channel, it's not possible to run a second analog input task or to add a second channel on the fly. You had mentioned that it's possible to read from the instrument through GPIB. Is it possible to perform a software trigger such that at a certain frame of your structure, when the trigger signal A reaches voltage "x", a GPIB command is written to your power meter to query a measurement reading?
Additional questions:
How do I configure the PFI0/Trig pin on the 6036E DAQ board individually as an INPUT?
You do not need to explicitly configure the PFI0 line as an input. If you want to use it as an input such that it acts as an analog trigger, simply wire the trigger signal to this pin. When configuring the trigger in your software, specify PFI0 as the trigger source.
How do I use an analog trigger signal (A) as counting signal for a loop, or as an activation signal for a sequence structure which includes GPIB commands?
You can try using the Limit VI to find out when the trigger signal reaches a certain level, and count how many times this level is reached. Similarly, you can use this as the condition to execute GPIB commands.
Hope this helps,
Lesley

How can I connect the output of a force transducer unit(BNC cable) to the PCI-6036E DAQ card via the SCB-68 block connector?

I m using the 404A force transducer unit by Aurora Scientific and i want to connect the (converted to Volt) output, which is a BNC cable, to the PCI-6036E DAQ card via the SCB-68 connector block, facing difficulties in choosing the correct input mode for my signal(couldn t clear this using the manual), setting the switches and which channel shall i use in the block connector in order to configure ot with LABVIEW

Hi MSc Student,
Connecting your transducer to the 6036E card via the SCB-68 connector block should be pretty straight forward. You have 2 choices of input mode, Referenced Single Ended (RSE) this is where you will connect the screen of the BNC cable to a ground connection for the DAQ card in the SCB-68 and the other to any analogue input channel . These are listed in the device pinouts in the help section of MAX, under the 68 pin devices section. The terminal block numbers correspond to the DAQ card's pin numbers. Another method, which avoids ground loop problems would be to use the Differential connection and connect the signal and ground connections of the BNC cable to a differential analogue input, these are listed in the 6036E manual and in th
e MAX help section again. the disadvantage to using this method is 2 analogue input channels are used and you must use the lowest 8 analogue input channels for differential inputs.
The switch settings that you need can be found in the manual for the SCB-68 in table 2-1, the manual can be found here : http://www.ni.com/pdf/manuals/320745b.pdf
The switches are for power to extra signal conditioning and the cold junction compensation for thermocouples which in your case you do not need so set the switches to the positions in the first box ie Direct feedthrough, with temperature sensor disabled and accessory power disabled. The channel you use should not matter the only ting to remember will be that if you use differential mode measurement that you will be connecting the signals to AI(n) and AI(n+8) so differential input 0 is across the connectors for AI0 and AI(8). The channel numbers corespond to the analogue input number for the card.
I hope this information helps,
Chris M
App
lications Engineer, National Instruments

What is the maximum number of samples that can be acquired with a single trigger using PCI-6036E DAQ card?

1. My PCI-6036E card has a FIFO of 1024 bytes in AI. Maximum how many samples can be acquired with single trigger for digitizing a waveform?
2. PCI-6036E DAQ card has got a AO with 10ks/s update rate? Can I generate a pulsed output with the AO of this card? I need a pulse of, say, 5 V and 1 kHz frequency.

Giri,
1.The trigger is usually for enabling the acquisition. I mean, when it is logic zero, you acquire nothing; however, when it is logic one, you start acquiring your waveform,and you can acquire continuously without having to worry about how many samples, unless you want to set your program for doing so. You can acquire continuously by implementing buffer acquisition. Finally, the FIFO that is in the board will not affect the buffer acquisition.
2.Yes, you can do that! You can generate your 5V signal with that specific frequency, and you should not have any problems, because the freq fits in the update rate.
I hope this information is helpful.
L Aguila
Applications Engineer
National Instruments

My 6036E DAQ Card is not running at its full refresh rate

I am using a DAQ PCCARD on my desktop ( I have a PCMCIA to PCI converter). I am running NI-DAQ 7.2 and i am having trouble getting the card to run at its full refresh rate. If i set the card at a scan rate of 1000 and acquiring 100 samples at a time, i get an error that says ive reached the system and or bus limitations in Labwindows CVI. Does this mean that the PCI to PCMCIA Converter is not fast enough to keep up with this scan rate or is another problem?

Assuming the DAQ card can sample at 100 kS/s, the problem is most likely the converter. The PCMCIA bus can transfer data at speeds up to 20 MB/s and the PCI bus, running at 133 MHz, can transfer data at speeds up to 1 GB/s. With this being said the PCI bus is much faster than the PCMCIA bus and will be able to handle the PCMCIA's slower transfer rate. The converter, however; will most likely introduce some latency in the transfer between the PCMCIA and PCI buses. This would result in the error seen when running at near the maximum sampling rate.

How to display the binary code received from a DAQ Card

Hi everybody,
My LabVIEW application receives data from a NI-6036E DAQ Card. Is there a possibility to see the binary code sent by the card? Because all what I found show only the analog value.
Thanks for your help

Assuming that you are using DAQmx, simply select the polymorphic selector of the DAQmx Read and do a Analog>Unscaled and then pick the type of integer array you want. If you are using the DAQ Assistant, I don't think you can select unscaled for that so you could convert the assistant to a VI and modify that (right click on it and select Open Front Panel). If you are not using DAQmx, please provide the name of the function you are using.
Message Edited by Dennis Knutson on 01-08-2007 08:31 AM
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Will there be a problem if i use DO and connect it to Gnd on 6036E DAQ ?

I am trying to use DIO channel 0 as digital output(set at 'high' always) and connect it to analog channel 0. I then plan to use gnd to break the circuit. So, analog input will give me 'high' always except when i gnd it. Will i burn up my DAQ card by grounding DO to Gnd.

Hey Jake,
I would never recommend doing this. The digital lines on the 6036E have no isolation and they would surely burn up if they were driving 5V and tied to ground. This would be exceeding the rated 13mA.
I would suggest using the digital outputs to control an external relay that could be used to switch the line from a 5V external power source or ground. In any case you want to turn off the 5V or disconnect the 5V circuit before pulling any line to ground.
I hope this helps out.
Joshua P.
Application Engineering
National Instruments

How can I create software start and stop trigger in LabView using 6023E series DAQ card? I don't want to use the external trigger.

I am using 6023E DAQ card to collect the signals, such as AE, Force, Torque from the machine. I want to collect only some part of signal for example between start triger and stop trigger. I'd like to know how I can creat those triggers in LabView from one of the channels that I am acquiring at the same time. I found one or two library file that is only for start trigger. I know that this is availabe in some of DIAdem functions. Please let me know if you have done some example for this requirement.

If you are wanting to create a software trigger based on an analog input voltage in LabVIEW, there are several options. One suggestion would be to compare the voltage values from one input channel to a number within a loop. If the input voltage crosses that threshold (is greater than the number), have a case statement that will acquire data from the other channels. This would simulate a software start trigger in LabVIEW.

Im using a pci-6221 daq-card.I want to know the difference(use)of a line output and a port output.

Im using a pci-6221 daq-card.I want to know the difference(use)of a line output and a port output.

Hello Hellraiser24,
This question has actually been discussed in another thread here:
http://forums.ni.com/ni/board/message?board.id=170&message.id=95895&requireLogin=False
I hope this helps,
E.Lee
Eric
DE For Life!

I am going to buy a second Apple TV. When I turn on Apple TV with the remote app, will it activate both Apple TV boxes or will it allow me to select the one I want to operate?

I am going to buy a second Apple TV. When I turn on Apple TV with the Remote App, will it activate both Apple TV boxes or will it allow me to select the one I want to operate?

The remote app will distinguish between the two Apple TV's, you won't need to pair it, it will only control one Apple TV at once.

6534 DAQ card- i want to process continous stream of data....through DAQ card...

I have NI -6534 DAQ card.i have continous stream of 16-bit parallel data. I use two port as input port .(16 bits parallel data), such that i recieve 12000 bytes per second in my card buffer. i use DIO read.vi. then on this bunch of 12000 bytes, i do some processing and display a XY chart/waveform.
code structure is as follows:
1) DIO config. vi
2) DIO start. vi
3) while loop
    {          DIO read.vi (reads 12000/or fixed number of bytes, inserts into an array )
               Insert array.vi
           while loop(this processes data till end of 12000 bytes,then stops)
                        stacked sequence(this processes the 12000 bytes data, )
                        (     seq 0: intialize counters,
                        seq 1: extract some pre-defined bytes,convert and display on frontpanel
                                          seq 2: extract specified bunch of bytes, create xy chart/waveform
                             }(12000 bytes data ends)
     }(16-bit parallel data is unavaible/or user control stop)
4)dio clear.vi
the problem persceptable here is , that processing data takes time.. few seconds for processing bucnh of data..then goes back to DIO read to fetch new bunch of data. till then the front panel waveforms and digital displays are on hold/static.
I want to process data simulatanouesly , and also being recieve in buffer through DAQ.real time processing.
simulatanoeus aqcuuistion..and process on continous data rather than in bunch of data.(i.e. TWO vi. should run in paralell DIO READ.vi acqusition...and process.. on that data(vi) )
Can queue.vi slove this problem? any other method
your help is greatly appreciated..Thanks.

Hi,
This is definitely something that can be solved using a producer consumer loop. You would have two loops running in parallel, have all of your data acquisition/generation done in the producer loop. Use queues to transfer all that data from the producer loop to the consumer loop and then do any kind of processing in your consumer loop.
The producer and consumer loop will run in parallel, and the consumer loop cannot run faster that the producer loop.
The good thing is that you can get a producer consumer template easily. In the LabVIEW startup window, select New (not New VI) >> From Template >> Frameworks >>Desgin Patterns >> Producer/Consumer Design Pattern (Data).
Hope that helps.
Regards,
Raajit L
National Instruments

Modbus protocol and NI DAQ Card

Hi,
I'm using an AC drive that supports the standard protocol Modbus RTU over RS485. I want to know if your data acquisition cards (eg. NI DAQCard-6036E for PCMCIA) are suitable to interface between this AC drive and a computer. Also, I will be using Labview to control and monitor the system.

Hi what,
If your AC drive uses the Modbus protocol over RS-485 then you will probably want to use the serial port or an RS-485 port to communicate with your AC drive from LabVIEW. I believe Lookout also comes with an OPC server which can communicate Modbus. Anyway, I suppose you could use the digital lines of the DAQ card to control your drive but it sounds like an RS-485 port (serial) would be more effective and easier than programming the DAQ board.
Anyway, hope that helps. Have a good day.
R

Can I use ARM LM3S8962 like a DAQ card?

I have the ARM embedded software and have used it to write some programs that run on the LM3S8962. What I'm wondering is if I can have a program that runs on the PC that "talks" to the ARM board occasionally to query the inputs or control outputs. If it is possible, how would I do that?

You absolutely can use an ARM LM3S8962 like a DAQ card, the only restraints you have are how fast the microprocessor can run and the limited amounts of AI you have available on the Luminary board. you can simply add an AI elemental I/O node to your project and wire your transducer to the luminary board. You then can take the data from the microcontroller and send it to the Host PC through a network published shared variable. There are a couple of tricks to this that may not be completely evident. I have included two links that I think will help you get to where you want to be. The first is setp by step how to connect an accelerometer to teh ARM board, but you can modify it for your own transducer.
http://decibel.ni.com/content/docs/DOC-9614
The second is hwo to use network published shared variables on an ARM board. I hope this helps!
http://digital.ni.com/public.nsf/allkb/6E50B28DDC61C0E68625767400805AA0
Scott W
National Instruments
Applications Engineer

How to acquire data from 2 chs of the same DAQ card at different sampling rate

I am using single DAQ card (either 6013 or 6014) in my system i want to acquire data from 2 (or more) channels with following requirements
1. sampling rate of each channel should be independant of each other (say one is 20 Hz and other is 15 kHz)
2. data from all the channels should be acquired simultaneously.
3. coding must be done using DAQmx VIs
I have tried out following things
1. I created separate task for each channel: i found out that two tasks can not run simultaneously even though the channels are different
2. I tried out single task with two channels included in it. and i used 'channels to Read' property to determine from which ch. i want to acquire data: this method works fine if the sampling rates are same. but if i change the sampling rate of one channel it gets reflected in other channels as well.
can somebody help me out to solve this problem.
i will appreciate if somebody can post the sample code as my deadline is approaching
Tushar Jambhekar
[email protected]
Jambhekar Automation Solutions
LabVIEW Consultancy, LabVIEW Training
Rent a LabVIEW Developer, My Blog

Hi Dennis Knutson
Thanks for your suggestion.
Tushar Jambhekar
[email protected]
Jambhekar Automation Solutions
LabVIEW Consultancy, LabVIEW Training
Rent a LabVIEW Developer, My Blog

How to structure the DMA buffer for PXie 6341 DAQ card for analog output with different frequencies on each channel

I'm using the MHDDK for analog out/in with the PXIe 6341 DAQ card.
The examples, e.g. aoex5, show a single Timer (outTimerHelper::loadUI method), but the example shows DMA data loaded with the same vector size.
There is a comment in the outTimerHelper:rogramUpdateCount call which implies that different buffer sizes per channel can be used.
(the comment is: Switching between different buffer sizes will not be used)
Does anyone know what the format of the DMA buffer should be for data for multiple channels with different frequencies ?
For example, say we want a0 with a 1Khz Sine wave and a1 with a 1.5Khz sine wave. What does the DMA buffer look like ?
With the same frequency for each channel, the data is interleaved, e.g. (ao0#0, ao1#0; ao0#1, ao1#1, ...), but when the frequencies for each channel is different, what does the buffer look like ?

Hello Kenstern,
The data is always interleaved because each card only has a single timing engine for each subsystem.
For AO you must specify the number of samples that AO will output. You also specify the number of channels. Because there is only one timing engine for AO, each AO will channel will get updated at the same time tick of the update clock. The data will be arranged interleaved exactly as the example shows because each AO channel needs data to output at each tick of the update clock. The data itself can change based on the frequency you want to output.
kenstern wrote:
For example, say we want a0 with a 1Khz Sine wave and a1 with a 1.5Khz sine wave. What does the DMA buffer look like ?
With the same frequency for each channel, the data is interleaved, e.g. (ao0#0, ao1#0; ao0#1, ao1#1, ...), but when the frequencies for each channel is different, what does the buffer look like ?
In your example, you need to come up with an update rate that works for both waveforms (1 KHz and 1.5 KHz sine waves). To get a good representation of a sine wave, you need to update more than 10x as fast as your fastest frequency...I would recommend 100x if possible.
Update Frequency: 150 KHz
Channels: 2
Then you create buffers that include full cycles of each waveform you want to output based on the update frequency. These buffers must also be the same size.
Buffer 1: Contains data for the 1 KHz sine wave, 300 points, 2 sine wave cycles
Buffer 2: Contains data for the 1.5 KHz sine wave, 300 points, 3 sine wave cycles
You then interleave them as before. When the data is run through the ADC, they are outputting different sine waves even though the AO channels are updating at the same rate.

I want to operate my 3 6036E DAQ cards in a master slave arraingmen​t

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I want to operate my 3 6036E DAQ cards in a master slave arraingment