Furuno FM-8800D Service Manual page 155

ANTENNA BAR INDICATION
This indicates ratio (SNAD) between the level of audio range and the level of noise
range. Just as SQ control, they are detected by SQ Cont inside DSP.
Adequate SINAD conversions of AF output are below.
- No antenna indication : no signal received.
- One antenna
- Two antennas
- Three antennas
COMMUNICATION WITH REMOTE HANDSETS
Communication between the Transceiver unit and a Remote Handsets are carried out
using RS-485.
The communication speed is 57.6 kbps/asynchronous communication and is carried out
with multi-processor function. With this equipment, polling is carried out at all times
towards each Remote Handset to monitor the state of it. For example, when any key on
a Remote Handset is pressed, a responding action will be carried out on the Transceiver
unit side and also sends its control command to the Remote Handset.
MULTI-PROCESSOR FUNTION
This is a function installed in H8S CPU. This function allows the shared use of
communication line between multiple CPUs and TX/RX of data through asynchronous
serial communication by adding multi-processor unit to it.
CPU
(H8S)
DMC I/F
(IF-8820)
Start
1 bit
Note;
Connection of DMC I/F cannot
be performed in the Russian Ver.
: below 20 dB SINAD
: 20 dB to 40 dB SINAD
: over 40 dB SINAD
Polling
Reply
ID=1
CPU
(H8S)
Remote Handset
(HS-8800)
MPB
ID data
0 D0 D2 D3 D7
Fig. 5.4.19 Multi-Processor Unit
Polling
FM-8800S, D
CPU
(H8S)
DATA A, B
ID=2
CPU CPU
(H8S) (H8S)
Remote Handset Remote Handset
(HS-8800) (HS-8800)
Start
Stop
bit
bit Data
1 1 0 D0 D2 D3
5-23
5.4 Block Description
ID=3 ID=4
CPU
(H8S)
Remote Handset
(HS-8800)
Stop
MPB 1
bit
D7 0 1 idling
MPB: Multi Processer Bit