Acquire single point 12 bit data @ 200Khz using PXIe 6535 DIO RT

I want to acquire single point 12 bit data @ 200Khz using PXIe 6535 DIO, PXIe 1072 chasis and 8820 controller in RT. Problem is I am unable to acquire data as triggered input. Loop execution time takes ~10us (measured using rt tick count). Thus It misses the samples. Am I missing something? What are the proper ways to acquire digital data in RT?
Also I am wondering whether I can use the SMB connector of 8820 controller as my acquision trigger input pulse. I am completely new to RT. Any help will be appriciated.
Thank you.

Hi jtele1,
To make sure that the data gets written in the correctly order I would recommend monitoring the Time Out of the write. If a time out occurs you could stop writing all FIFOs and then start when all the Time Outs are no longer there. Another option is to look at your host side and determine if you can read larger chunks of data at a time and allow the host side to deal with processing the data. An additional option would be to look into high throughput streaming for FlexRIO. In this setup you will be writing the data directly to disk on your host side and then you could process the data at a later time. I have linked an example below, this example was giving me trouble so please let me know if you have trouble loading this example. Depending on your situation these may not all be acceptable options but you will need to ensure that you are not filling any of your FIFOs. Lastly, from what I can tell you are using a Windows OS as your host and in that situation you have no way of controlling when your LabVIEW application gets processor time. If you were to switch to a Real Time controller you would be able to ensure when certain tasks are run and add priority to tasks. Please let me know if you have further questions.
High Throughput Streaming
https://decibel.ni.com/content/docs/DOC-26619
Patrick H | National Instruments | Software Engineer

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PXI5124-data-acquisition.vi ‏46 KB

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ADVExtractDLL.zip ‏9 KB

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Hello,
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Hi jilla,
jilla wrote:
What I think that you are saying is to turn the outputs of the 4 subVIs into inputs of a 5th subVI that writes to the data file. Correct?
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One more question: at what point (either # of data points or frequency of data collection) does it become necessary to use queues? Thanks.
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Attachments:
Keithley 24XX Sweep and Acquire Measurements.vi ‏26 KB
Basic Serial Write and Read (1).vi ‏26 KB

The following video demonstrates how to check the firmware revision: http://www.keithley.nl/centralized_display?mn=2400&assetid=55934.
In order to update the firmware you will be need to download a flash program and the firmware file. gAfter obtaining the Flash program and the Firmware file from Keithley Application support staff, unzip the three files in a folder of your choice and run the "setup.exe" program. Follow the instructions to install the program. When the installation is complete, launch the program from your Windows Start menu under Programs/Keithley Instruments. The Application support staff will also provide the file for the latest firmware revision. Put that file in a folder where you can find it and then run the Flash Wizard32 program. The program will autodetect the instrument and request to specify the firmware file.
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Solved!
Go to Solution.

Here's how I would do it with no formula nodes or loops requied:
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Notifier Data Transfer Template.vi ‏62 KB

Here is an example of a race condition without the use of local or global variables. What is happening is that the notifier is already queued up with a value even before the Elapsed Timer has even started. So one extra value will be in the output array. Also, depending on how the parallel loops perform (which goes first), there may be an extra value queued up before the Time Elapsed event could fire. Typically, when I ran it, I got an array size of 6 at first, and then it went down to 5. Clearly the architecture is not right for what you want to do. Instead of depending on timers and parallel loop timing, you could receive all the values queued and just discard the ones you don't want.
- tbob
Inventor of the WORM Global

Acquire single point 12 bit data @ 200Khz using PXIe 6535 DIO RT

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