Furuno FAR-2107 Series Service Manual page 390

Overview of EAV-3 processing
EAV-3 processing is not the correlation processing like EAV-1 and 2. In this
processing, unwanted signals that cannot be processed in FTC and STC are
emphasized.
At the maximum input signal level (level 32):
The previous signal is compared with the current signal. If the current signal is at
the maximum level, it is outputted at the level. If the current signal is weaker, it is
outputted at a level a little lower than the maximum level.
In the medium input signal level:
The previous signal is compared with the current signal and the output level is
gradually raised. If there is no signal, the output level is gradually reduced. The
rate of reducing of the signal level in EAV-3 is slower than in EAV-1 and 2.
The figures below show input signals of EAV-3 and EAV output level in a simplified
way. Although there are 32 signal levels, they are shown in 0 to 7 levels in the figures
below.
EAV-3
7(Max.)
32 level
6
5
4
3
Input-1
2
1
EAV out-1
0(Min.)
0
Input-2
EAV out-2
Input-3
EAV out-3
n n+1 n+2 n+3
7(32)
6
5
4
3
2
1
0
0 0 7 7 7 7 7 7
0 0 7 7 7 7 7 7
n n+1 n+2 n+3
7(32)
6
5
4
3
2
1
0
0 0 4 4 4 4 4 4
0 0 4 5 6 7 7 7
n n+1 n+2 n+3
7(32)
6
5
4
3
2
1
0
6
0 0 7 0 0 0
7 5
0 0 7 6 6 7 6 5 5
Fig. 7.3.１5 I/O level of EAV-3
7-46
Scan
7 0 0 0 0 0 0
7 6 5 4 3 2 1 0
Scan
4 0 0 0 0 0 0
7 6 5 4 3 2 1 0
Scan
6
0 0 0 0
7
7 7- 6 5 4 3 2 1
7.3 Processor Unit: RPU-013
0