Setting TCP timeout before a new connection is created

[Kipper1258]

Hopefully someone can help me with this. I've notice that OpenCPN closes the TCP port and opens a new one if it does not see any NMEA sentences within about 30 seconds. Is there anywhere I can configure that timeout and increase it to what I need. This behavour is causing some of the NMEA feed devices I use to fall over because too many sockets have been opened. TIA.

[transmitterdan]

Originally Posted by Kipper1258

Hopefully someone can help me with this. I've notice that OpenCPN closes the TCP port and opens a new one if it does not see any NMEA sentences within about 30 seconds. Is there anywhere I can configure that timeout and increase it to what I need. This behavour is causing some of the NMEA feed devices I use to fall over because too many sockets have been opened. TIA.

It is a hard coded 5 second timer. If no data is received for 1 second then a counter is decremented. It starts at 5 and when the counter hits zero then O closes the socket and waits about 5 seconds and tries to reopen the connection.

It would not be hard to make both of these values a setting in the configuration file. Submit a flyspray enhancement request and try to describe in detail what you need and why it is important.

But really, these other devices you describe are technically "broken". They should also have timeouts on their connections and close them so the sockets can be reused. So it appears you are asking for a bandaid and perhaps the best medicine is to get these other devices to behave properly.

[Kipper1258]

Thanks for this. Is the 1-5 seconds for any form of data on the port, or only useful NMEA sent? I do need to check how the NMEA server on board is configured as it is the first time we have sailed the boat with an NMEA feed from a 2004 Silva-Nexus server.

[transmitterdan]

It does not check for a full and proper NMEA message. The watch dog starts again after receiving a chunk of data over the TCP connection.

[Kipper1258]

Originally Posted by transmitterdan

The watch dog starts again after receiving a chunk of data over the TCP connection.

Excellent! I'm using a USR-W600 to convert the serial signal into WiFi. It has a heartbeat function where I can configure the data sent and frequency. My backup if I cannot sort out the Nexus server calibration. Thanks once again for your help.