Open a shell for the Provider Simulator and another shell for the YAMCS-SLE client. Launch the Provider Simulator first and then the YAMCS-SLE client.
To launch YAMCS using sitl_commander_workspace, you must first make the workspace following the instructions from airliner/README.md
Provider simulator shell
./bin/yamcs-start /opt/yamcs .
./bin/yamcs-start /opt/yamcs .
This should launch YAMCS from the sitl_commander_workspace directory.
When YAMCS is lauched, sle-client will be in READY state. To go to ACTIVE state navigate to "more actions" and select "Start SLE".