Yacht Devices YDWG-02, Руководство пользователя

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V. NMEA 0183 and NMEA 2000 Message Filters
The Device has 14 filter lists which allow limiting the set of messages passed from
the NMEA 2000 network to a PC or mobile application (transmit filters) and messages
passed from the application to the NMEA 2000 network (receive filters).
Each NMEA server has four filter lists: two for incoming and outgoing NMEA
0183 messages, two for incoming and outgoing NMEA 2000 messages (used
for RAW protocol). Which filter is used depends on the server data protocol settings
defined on the “NMEA Servers” page. There are 12 filter lists in total.
The Device also has two “Global” filter lists, which define what NMEA 2000 messages
can be passed from the network to internal NMEA servers and what NMEA 2000
messages can be sent by internal NMEA servers to the NMEA 2000 network.
Each filter list has a switchable type: WHITE or BLACK. A message is passed
thru the WHITE filter if it contains a record matched with a message. And the reverse
for BLACK. In the factory settings, all filter lists are empty and are of BLACK type,
so all messages are passed through the filters.
1. Syntax of NMEA 0183 filters
NMEA 0183 filters contain 3-char NMEA 0183 sentence formatters separated
by a space character. According to the standard, an NMEA 0183 sentence starts with
a $ or ! symbol, followed by a two-character talker ID and a 3-char sentence
formatter. These elements are followed by data fields (after the comma).
The sentence is finished by a check sum after the * (asterisk) symbol.