Keithley 8010 Reference Manual page 10

Using both sides of the test fixture
In several of the interconnection diagrams, it is noted that you can
make equivalent connections on the other side of the test fixture. For
example, if you have an ongoing test using the Series 2600 connected
to the high-current side, you could set up a one-time test using the
equivalent terminals on the high-voltage side.
Note that this option is not available for test setups when you are
using a Model 2651 or Model 2657.
Do not simultaneously connect terminals in the high current and
high voltage areas of the fixture to the same terminals in the
center area (the area bordered in blue). Simultaneous
connections can result in electric shock (see previous graphic).