The channels of the ASIO driver Routling is running on - the lowest-latency path, since they share the engine's clock.

First add the driver: right-click → ASIO Channels → Add ASIO driver…. Then ASIO Channels → Input or Output lists its channels by the names the driver gives them.

Every channel is one mono node. A stereo signal is two nodes, wired left to left and right to right:

Music L
ASIO/Focusrite USB ASIO
Output
Mono
Music R
ASIO/Focusrite USB ASIO
Output
Mono
Out 1 (L)
ASIO/Focusrite USB ASIO
Input
Mono
Out 2 (R)
ASIO/Focusrite USB ASIO
Input
Mono

If the driver reorders its channels (ASIO4ALL does when a device is plugged in or out), each node follows its channel. Stopping or switching the driver removes its channel nodes; Routling asks first.

ASIO® is a registered trademark of Steinberg Media Technologies GmbH.