TCP Ports

Discussion and support for the Nmea4Wifi multiplexer - a 4-input Nmea 0183 wifi multiplexer.
mikeweston
Posts: 10
Joined: Fri Sep 25, 2020 5:26 pm

TCP Ports

Post by mikeweston » Wed Oct 21, 2020 5:55 pm

Still bench-testing my new NMEA4WiFi unit. I am new to much of TCP and UDP setup. Can anyone offer direction on establishing a TCP or UDP bridge to a virtual serial port? I use SeaClear on Win 10 for navigation and it is looking for one or more COM ports to accept NMEA 0183 from.

I have tried TCP-Serial from CommFront to create a bridge from TCP or UDP to a serial COM port with no success. SeaClear reports "could not open communication port x".

Luis Sa
Site Admin
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Joined: Thu May 04, 2017 4:12 am

Re: TCP Ports

Post by Luis Sa » Fri Oct 23, 2020 2:55 am

Hello,

I do not know SeaClear nor CommFront in order to give you a tip. If you can be more specific I will try to help.

REgards, Luis

mikeweston
Posts: 10
Joined: Fri Sep 25, 2020 5:26 pm

Re: TCP Ports

Post by mikeweston » Fri Oct 23, 2020 3:28 am

Luis,

I don't think this is unique to SeaClear. I believe OpenCPN on Windows would require the same sort of setup. These programs can only accept data from a serial COM port; they cannot directly access a TCP or UDP feed. Something must be in place to tie the TCP/UDP broadcast by the NMEA4Wifi to a virtual COM port. The programs open the access the COM port and read the NMEA sentences from there.

This is how I *THINK* it would work. I am not very fluent in network protocols.

Mike

mikeweston
Posts: 10
Joined: Fri Sep 25, 2020 5:26 pm

Re: TCP Ports

Post by mikeweston » Fri Oct 23, 2020 3:56 am

Correction. Looking at the most recent OpenCPN documentation, it appears to allow direct setup of TCP or UDP over Wifi. However, I do not use OpenCPN. SeaClear wants a COM port for input of GPS or AIS.

Luis Sa
Site Admin
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Joined: Thu May 04, 2017 4:12 am

Re: TCP Ports

Post by Luis Sa » Fri Oct 23, 2020 4:47 am

Hello Mike,

It looks like you need an adapter. Have a look to this post:

https://www.vela-navega.com/forum/viewt ... p=424#p424

If SeaClear is not able to communicate by WiFi you will need a wired connection.

Regards, Luis

dagnall
Posts: 459
Joined: Wed Mar 04, 2020 6:36 pm

Re: TCP Ports

Post by dagnall » Fri Oct 23, 2020 4:35 pm

I used to use a program that would only take serial and spent a while finding an approach using free software.
  • First, you need to set up a virtual serial port - in fact a virtual serial port null modem pair..
  • Then you need a Serial -TCP program like "Serial-TCP" this links a network IP TCP to one of the virtual serial ports.
  • The Navigation program can then connect to the "second- linked" virtual serial port. Setting it all up can be a bit complex, but it can work..(Photo of it working with "com11" and "com12" and showing the simulated data from a NMEA4WIFI..)
  • I have only tested it reading data. I have not used it to send data back to an autopilot.
Personally I found the TCP-virtualSerial-virtualSerial-Nav program approach a bit complex, and prefer QTVlm or OpenCPN, which can both connect "native" to TCP or UDP. If you have a choice I actually use and would recommend InavX on an Ipad (I think Inavx is also available on other platforms now).


The links can be hard to find, so I have popped them below..
Virtual null modem : https://sourceforge.net/projects/com0co ... t/download
Serial-Tcp: https://www.commfront.com/
Dagnall
Screenshot 2020-10-23 172135.jpg

mikeweston
Posts: 10
Joined: Fri Sep 25, 2020 5:26 pm

Re: TCP Ports

Post by mikeweston » Fri Oct 23, 2020 6:46 pm

Brilliant. That did it. Part one, creating the port was a bit funky, but after that, CommFront worked great to bridge UDP to the virtual serial port. I will work on TCP next, then bi-directional.

I will likely move on from SeaClear. It works, I finally got comfortable with the rather obtuse GUI, but it is definitely out of date.

Thank you so much. You have saved me countless hours (on top of the countless hours already sunk).

dagnall
Posts: 459
Joined: Wed Mar 04, 2020 6:36 pm

Re: TCP Ports

Post by dagnall » Fri Oct 23, 2020 9:31 pm

Mike,
Thanks for the feedback! Glad it helped.
I discovered Qtvlm by buying the UKHO chart usb from visitmyharbour, and it was on the usb stick. Its perhaps less clean to use than seaclear, but the grib and planning gizmos inside are fascinating. In these times of enforced non sailing I find myself looking at the grib forecasts and being fascinated by the passage planning that can even take into account your polar performance!

(Usual disclaimer, I have no relationship with visitmyharbour or QTVlm!)
Dagnall

mikeweston
Posts: 10
Joined: Fri Sep 25, 2020 5:26 pm

Re: TCP Ports

Post by mikeweston » Sat Oct 24, 2020 11:09 pm

Dagnall,

The CommFront port bridge shuts down the ports after 3 hours (free version). Are you aware of a similar product?

Thanks
Mike

mikeweston
Posts: 10
Joined: Fri Sep 25, 2020 5:26 pm

Re: TCP Ports

Post by mikeweston » Sun Oct 25, 2020 3:09 am

TCP Serial Bridge - free, seems to work fine for TCP, but does not have a UPD option. Still looking.

sourceforge.net/projects/tcpserialbridge

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