The second column of LEDs in the back of the ZHC unit indicate the pilot tone status of the unit.
- A solid RED LED indicates the unit is in SATELLITE mode. This means and it has locked its distance from the preceding unit whether it is a MAIN unit or a lower level SATELLITE unit.
- A solid AMBER LED indicates that the unit is in MAIN mode. This means the pilot tone is turned on. This should only occur during the first 8 hours of operation of the MAIN mode. The AMBER LED will turn off automatically after 8 hours and will come back on when the MAIN unit is rebooted, restarting the 8 hour timer.
- A flashing GREEN LED indicates that the unit is preparing SATELLITE mode. This means that the unit is still waiting to lock on to the preceding MAIN unit or a lower-level SATELLITE unit. The GREEN LED will flash for 20 minutes once a consistent pilot tone is detected, after which it will turn OFF. Once the GREEN LED turns OFF and the tone is locked, RED LED will turn ON.
NOTE: The first column of LEDs on the rear of the enclosure are used entirely for internal manufacturer testing and will not be operational under normal use.