Handset; Communication Priority - Furuno FS-1570 Service Manual

1.5 Handset

Either HANSET (HS2001) port or HANDSET/MIC (HSC-701K-20B) port is used. Do not
use them at the same time. HOOK and PTT lines of these ports are connected in parallel.
HOOK signal:
- AUTO ACK of DSC does not work when the handset is off-hooked.
- When the handset is off-hooked, "Occupied Another Controller" appears on the display of
another FS-2570C. No.1 controller works even when the handset is off-hooked on No.2
controller.

1.6 Communication priority

DSC distress alert has the highest priority. No priority is placed on other functions.
Fig.1.5.1 Block diagram of C-IF
1-6
1.5 Handset