2461 Negative log sweep

How do I create negative current (i.e. sink mode) logarithmic sweep on 2461? Preferably on front panel if possible.

The sweep generator won't allow negative numbers. Mathematically understandable, but practically there should be means to do that(?)

I am not aware of a way to do so automatically (given the log sweep definition and general incompatibility with negative numbers.) It's possible some kind of 'invert polarity' feature could be created as an enhancement with a customer use-case definition to help specify what is needed.

If you simply want to invert the polarity of an entire log sweep, there are a couple of options that may help workaround:

1) If your test setup allows for it, program the positive polarity version of the sweep you are trying to create and swap the HI and LO terminal leads. This will reverse the polarity of both current and voltage, but it's a simple option for a quick manual test that may not be acceptable depending on your requirements.

2) Generate your desired positive-log sweep, and edit the resulting source config list to negate the source values as needed.
    Create all desired settings as needed, generate the sweep, then select the Menu button -> and under Source select the Config Lists icon. Press the Select Config List button and choose the LogSweep config list (which should have been generated by the instrument sweep generation.) From there, you should be able to:

2a) Select each point, recall the index, press Home button to reach front panel, manually change polarity of the source value, choose Menu button and Config List icon under the Source section (far left of menu), and then select the point in question again and choose "Add Settings" and "OK" - this will update the polarity of each point. Settings for each point will need to be recalled, edited on front panel, and updated.

Depending on the number of points needed, it may be easier to programmatically generate a list sweep or consider creating a script to source the needed values.

If you wish to be able to save and recall your manual edits, I'll suggest also using the Menu->Scripts->Save Setup to save your settings once you have completed editing the sweep.