The NMEA Interface
The VDO 110mm gauges can be directly connected to a NMEA 2000 network
without using the Nav Box system.
Note: If using the gauges with NMEA 2000 following limitations have to
be exepted:
- The gauges are not NMEA 2000 certified but compatible
- The illumination of the gauges is always ON
- As soon as the NMEA 2000 power is switched off the indication
pointer will go back to the zero position
-The gauges will only read the NMEA 2000 PGNs listed below. No
calibration is possible through the gauges
- When data is available from multiple sources, the gauge
automatically selects the source with the lowest instance number
Please follow the general NMEA 2000 installation rules you can find at
www.nmea.org.
Calculation
12V power supply:
The voltage drop for every segment of the VDO Bus is calculated as follow:
Ohm‘s Law:
E (voltage drop) = I (circuit current) x R (wire resistance)
R= 2/2x Cable Length (m) x Power Pair Resistance / 100
I= LEN (Load Equivalency Number) x 0.050 amps
L=Total length of VDO Bus cables on one segment
→ E = 0.05 x LEN x L x 0.057
The voltage drop for each VDO Bus Segment shouldn’t be higher than
3V
Note: VDO BUS has
2x AWG 22 Power/Ground cables
→
different voltage
drop calculation than NMEA 2000
24V power supply:
If using a 24V system the voltage drop may not be higher than
9V
10
