The heartbeat you are referencing is sensor supervision.
Yes, all the sensors are supervised.
But again, the chart of the sensor’s pings shows it has not been hear from for hours. All very confusing…
The interval at which the panel reports failed supervision and offline status depends on programming and the type of sensor.
For life safety devices like smoke and CO, default supervision is 4 hours.
For non-life safety devices, default supervision is 24 hours.
You can find the supervision times and edit them under Settings > Advanced Settings > Installer Code > Installation > Installer Settings.
Does it has a signal quality LED for placement assist like the DSC sensors Wayne mentioned?
No, there is not an on-board signaling diagnostic. The panel can show signaling.
Open air range can be quickly shortened depending on the environment. Typically basements cause the most trouble as metal objects most effectively impact the RF signals. Water heaters, pipes, HVAC, duct work, nearby wiring all impact signaling.
Making sure the transmitter portion is not mounted on or close to metal is the most important. You can adjust the transmitter location to determine a good spot.
If you open the cover and the sensor reports a tamper on the panel, it can signal the panel from there, but check the signal strength reported under System Tests > Sensor Test.
Where is the full manual for these things?
The quick guide you reference is the full manual produced by Qolsys.