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dgiardini / rtl-ais

A simple AIS tuner and generic dual-frequency FM demodulator
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double/duplicate TCP messages ? #23

Closed LeaseOnLife closed 4 years ago

LeaseOnLife commented 4 years ago

I seem to be getting every message twice, via TCP to OpenCPN:

output of rtl-ais with "./rtl_ais -T -P 11111 -n -R on" : !AIVDM,1,1,,A,H4eIMs@L4hDpD00000000000000,0*68 output of OpenCPN/nmea debug window: 08:25:46 (TCP:127.0.0.1:11111) !AIVDM,1,1,,A,H4eIMs@L4hDpD00000000000000,0*68<0x0D><0x0A> 08:25:56 (TCP:127.0.0.1:11111) !AIVDM,1,1,,A,H4eIMs@L4hDpD00000000000000,0*68<0x0D><0x0A> this seems specific to rtl-ais, when using a PI4 as TCP server with an old NMEA0183 AIS connected via serial port, I am not getting duplicate messages.

dgiardini commented 4 years ago

rtl-ais as used as tcp listener (-T switch) kepps arriving messages in memory for 15 secs by default. The client, ie OpenCPN , gets all the AIS data available from rtl-ais so can pick many times the same message until is deleted. In most cases getting twice the same message is not a problem, but you can change this behaviour, using -t parameter in order to lower the time the messages are stored in rtl-ais memory.