The extension unit has built-in elements:

• Power - relay type element
  This element is identical to the element Analog Power of monitoring units. It turns on or off the power of analog sensors. Turning off the power of analog sensors for a few seconds is used to reset the alarm smoke detectors VT560 connected to the extension unit VT408.
  Warning: when the power of analog sensors is OFF, all connected to the VT408 external sensors are OFF.
  

The settings of analog sensors connected to the VT408 unit are similar to the settings of sensors connected to the monitoring unit.