ADALM2000 DC Sweep

Hello d72huang ,

You can use Scopy for a DC voltage sweep from -2V to 2V, but it is limited to a 4mV step size since the rising and falling transitions are restricted to 1024 steps. Refer to the image below.

Regards,

Rey

Hi,

Thank you for the information. Is there a way though to only do a singular run and not a continuous sweep. I would like to just do -2V to 2V one time and not have it be continuous.

Not from within the Scopy software. To do a "true" DC sweep you will need to use the libm2k API library and write your own procedural script probably in Python. libm2k is available from here: https://github.com/analogdevicesinc/libm2k there are bindings for MATlab and Labview as well.

Also, a little more background on why the minimum step size is 4mV. The DAC used for the AWG channels is 12 bits thus 4095 steps. These steps are mapped to the full output swing of -5V to +5V or a span of 10 V. Which is an ideal 2.4 mV per step. The 4 mV number includes other sources of error and noise etc.

A way to shrink the apparent step size for your -2 V to +2 V requirement would be to attenuate the full -5 to +5 range to your -/+ 2 V using a resistor divider and then perhaps buffering the attenuated voltage with an op-amp follower. The steps would now be 4/10 smaller (or 4mv * 4 / 10 = 1.6).

Hope this additional info helps.

Doug

Hi,

Thank you a lot for the help and information. I think the minimum 4mV step size is actually sufficient for the task I need it for. However, I was wondering if it would be possible to get some form of code just to see how it would like to get the singular -2V to 2V sweep. 

I was also a little bit confused as to how to setup lim2k. Was wondering if I could get some guidance as well. Thank you for the help. 

hello d72huang ,

You can check this (What is libm2k? [Analog Devices Wiki]) to get some information regarding on libm2k.

Regards,

Rey

Is there a possibility to get a few lines of code to get a better start for making -2V to 2V sweep?

Hello,

I added a reference example for generating a DC Sweep using the M2K, covering both signal generation and data acquisition. You can find it here: DC Sweep Example - Python

The bindings folder contains code snippets for various languages supported by libm2k. I also recommend checking the examples folder for C++ code references.


Hope you find this usefull.