— 16 —
traffic and CPU load, despite the fact that both clients receive the same data.
UDP is a connectionless protocol; any number of clients can listen to data broadcasted
from a specified port without any additional load on the server and without increasing
the actual network traffic. We recommend using UDP protocol where possible, because
the resources of the Device’s CPU are limited.
The Gateway supports RAW and NMEA 0183 data protocols. The RAW protocol
is supported in Expedition 10 and CAN Log Viewer. This protocol is very simple,
open and also supported by our USB Gateway YDNU-02. We hope that this protocol
becomes popular among software developers.
NMEA 0183 is supported in virtually all marine applications. The Gateway contains
a bi-directional converter between NMEA 0183 and NMEA 2000 and has a flexible
system of message filters (see V).
On the “NMEA Server” page on the administration web site you can set up to three
server ports (see Figure 2 on the next page). If TCP network protocol is selected,
up to three connections (from three different applications on one device, or from three
devices with one marine application running on each) are allowed at the same time.
So three servers allow nine connections in total.
In the case of using UDP protocol, the number of devices or applications used the data
port is not limited. We recommend using UDP protocol when possible.
Server port can be configured as bi-direction, read-only (Transmit Only) or write-
only (Receive Only). We recommend configuring data ports as read-only if possible,
to prevent network flooding from incorrectly configured applications.
