VNA Sweep Management

With spectrum and network analyzers, it can be important to know the sweep status of an instrument before retrieving data and making measurements. This is especially true with complex sweep modes on deep memory and high accuracy models.

For a summary of gathering data from network analyzers refer this guide.

There are some additional tips for knowing when to request the data especially during long sweeps.

On SIGLENT Network Analyzers, the best way to monitor the sweep state is to use the ':SENSe:SWEep:MODE?' command.

The Sense:Sweep:Mode command can be used to check for HOLD when the instrument is in SINGLE mode.

The best use case here is to enable and trigger a SINGLE BUS trigger. Then, poll the sweep mode for HOLD. Then, once that is complete, capture the data.

Here is an example program that allows you to do this and capture and graph the trace data using Matplotlib in Python:

And here is what the program output would look like:

The OPC? command is another common way to look for data readiness. SIGLENT Network Analyzers have a specific implementation of *OPC during extended sweeps. 

For this operation, make certain you have the latest firmware.

Once a sweep begins, the *OPC command will not return data until the sweep is completed. Therefore, we suggest using a error catching loop in case it times out before you get a response.

Here is what that looks like in Python:

Use the sweep mode command or the OPC command, depending on the situation, to understand the sweep state before requesting data from a network analyzer.