The sensor/health graphs show current and historical health scores, as generated by non-core sensors. Core sensor are the ones built into HAAst (non-configurable) and trigger an immediate failover upon detection of a critical issue.
User defined sensors generate scores that show up in the graphs and reporting. So if you have not defined any sensors then you will not see any graphs.
Note that some installations are satisfied with the core sensors only. But as you become more familiar with HAAst you will likely want to add some sensors (e.g. monitor the network/cable carrying SIP/RTP traffic from the PBX to the ITSP).
