User manual

Page 38© 2009 Active Research Limited
System block diagrams
Figure 26 – NDC-4 in ‘Combiner’ mode signal ow block diagram
Figure 27 – NDC-4 in ‘Autoswitch’ mode signal ow block diagram
NMEA
Filter
Port 0
USB Input
Circuitry
NMEA Opto
Input
Port 1
ISO Out 1
Port
Priority
Controller
ISO Out 1
(Combined)
Circuitry
ISO Out 0
Port
Controller
ISO Out 0
(PC)
Circuitry
USB
Output
Circuitry
Switches
to USB
when
USB
active
NMEA Opto
Input
Port 2
NMEA Opto
Input
Port 3
NMEA Opto
Input
Port 4
NMEA Opto
Input
Port 0
NMEA
Filter
Port 4
NMEA
Filter
Port 3
NMEA
Filter
Port 2
NMEA
Filter
Port 1
NMEA Opto
Input
Port 1
Autoswitch
Channel
Selector
ISO Out 1
Output
Circuitry
ISO Out 0
Output
Circuitry
USB
Output
Circuitry
NMEA Opto
Input
Port 2
NMEA Opto
Input
Port 3
NMEA Opto
Input
Port 4
NMEA
Filter
Port 4
NMEA
Filter
Port 3
NMEA
Filter
Port 2
NMEA
Filter
Port 1