The figure shows the recommended fluidic setup for the use of two column switching valves.
Follow these steps
Connect the Viper capillary from the pump or autosampler to port 3 of the bottom column switching valve.
Depending on the column position, connect an active or passive pre-heater to port 2 or 4 of the bottom column switching valve and connect it to the column inlet.
Connect a Viper capillary to port 1 or 5 of the top column switching valve and connect it to the column outlet.
Connect a post-column cooler or a Viper capillary to port 6 of the top column switching valve and connect it to flow cell inlet of the detector.