DASYLAB with Multiple MCC USB 1808X

[Ajmal]

Due to larger channel count, I have to run a test with 3 MCC USB 1808X modules.  Does single license of Dasylab supports the configuration with multiple USB modules?   

How to display multiple analog inputs on a single Y-t display chart?

The USB 1808X is capable of 200 kHz sampling rate with all 8 analog input channels sampled at the same time.  The Dasylab Measurement setup under A/D does not have sampling rate faster than 20 kHz.  In Dasylab how to increase the sampling rate past the 20 kHz?  In Dasylab how to enable simultaneous sampling of multiple analog inputs?

What data transfer rate is supported by Dasylab when streaming to the disk?  How is the streaming handled by Dasylab when you have multiple USB 1808X on the same computer?

Thanks much.

 

  

[DAQman]

There is no number of devices limitation with DASYLab. However, The LITE version has a restriction on the number of wires (64), which will limit the number of devices.

A single display plot can hold a maximum of 16 channels. Multiple devices are read one at a time, and that will skew the data slightly. You'll find that the Chart Record display is the most forgiving when you have misaligned data. You can align data using the Adaptation module located in the Special category. This module will align the data using channel 0 as a reference. I find that the Linear Interpolation method works best. 

On the Analog Input module dialog, press the Measurement button and choose Modify to change the rate to 200000. Above the Modify button, ensure the Timebase is set to USB-1808X Device Input HW. 

DASYLab can easily handle logging data to disk at rates over 1 M S/s. However, it may be less if you're using a CSV or TXT file because text data is ten times larger than binary.

[Ajmal]

On 9/25/2023 at 6:43 AM, JRys said:

There is no number of devices limitation with DASYLab. However, The LITE version has a restriction on the number of wires (64), which will limit the number of devices.

A single display plot can hold a maximum of 16 channels. Multiple devices are read one at a time, and that will skew the data slightly. You'll find that the Chart Record display is the most forgiving when you have misaligned data. You can align data using the Adaptation module located in the Special category. This module will align the data using channel 0 as a reference. I find that the Linear Interpolation method works best. 

On the Analog Input module dialog, press the Measurement button and choose Modify to change the rate to 200000. Above the Modify button, ensure the Timebase is set to USB-1808X Device Input HW. 

DASYLab can easily handle logging data to disk at rates over 1 M S/s. However, it may be less if you're using a CSV or TXT file because text data is ten times larger than binary.

1.  The Measurement Setup shows the current sampling set to 1000 Hz, but does not offer a way to change it.  See attached screen capture of the dialog boxes.

2.  What is meant by 100 samples/block?

3.  Text format (ASCII) files are larger and slower.  There are several other formats available including (a) DasyLab, (b) NI TDM, (c) NI TDM Streaming, (d) IEEE xx bit, (e) Famos.  Which of these formats are binary and which one would you recommend using if the objective is to write data to disk in real time?  After acquisition is complete, how to convert the binary data to ASCII off line?

Thanks much.

 

 

[DAQman]

1. Press the Modify button to change the sample rate - see image below

2. The block size is how many samples the Analog Input reads. For efficiency, DASYLab passes blocks of data to each module instead of a single value. 

3. The best one is the DASYLab format (.DDF). The other formats are there to support other software. For example, the file format FAMOS is used by Famos software, which is a graphical analysis package.