Driving a Ramp Wave into Multiple Channels

Okliam

I have a Python that should generate a Ramp wave using Zotino.

I attempted to output the same signal into two channel outputs, but only Channel 1 is outputting some kind of wave. I say this as in it is not generating the desired ramp but what looks to be a "noisy" wave or one with no definitive structure.

We are gathering Channel's output on the Moku app.
Currently, we have two cables plugged into Channels 1 and 2 to the Moku device.

Okliam

I figured the problem out, but on another note, I'd like to ask about this sample code of the RampOutput here.

Here, we expect the Voltage Amplitude to be 20V, but the output of this code on ARTIQ says otherwise.

The amplitude of the two channel outputs is 1.739 V, which is roughly 10 times smaller than the predicted amplitude value.

We also would like to ask why the sample code chooses the array values to be at intervals of 2¹⁶ (1<<16) // (n_step) = 655

This screenshot shows the array values of voltage_mu, and the number on the last line shows the output of (1<<16)//n_step

sb10q

Okliam We also would like to ask why the sample code chooses the array values

Where is that sample from?

Okliam

sb10q https://github.com/cnourshargh/Bham-ARTIQ-examples, using the Zotino_RampOutput.py python file.

Edit: I'd like to understand the purpose behind this function: self.zotino0.write_dac_mu(30, voltage). How different is this to the self.zotino0.write_dac(30, voltage), and is there a way to output the voltage values in the voltage_mu array in increments of 0.2V so that the we can obtain the Voltage Amplitude Peak-to-Peak of 20V, from -10V to +10V?

What are machine units and what is the conversion from Volts to machine units?

sb10q

In this case the values in "machine units" are DAC code words.