Is OpenCPN a client/server app ? Multiple clients ?

[AboutTime1]

I'm trying to figure out if OpenCPN has a client/server architecture underlying it.

If not, how does one run multiple instances of openCPN on a boat ? Let's say we have a dual helm monohull with a chart table down below and we want OpenCPN running at each location. How does one set that up ?

[StuM]

Something like TightVNC?
https://www.tightvnc.com/


Run it at the chart table and mirror it to a device at the steering station (can be a an Android tablet with Remote Ripple (same URL as above)).

[Hakan]

Or another concept. Not better. Just another for your choice.
One OCPN PC at the "chart table" with all wire/wire less connections from different devices. Make one output to network UDP. (Address 192.168.x.x port 10112 (Yes, actually .x.x))
One cheap "old time" 12 V router also down there.
Then you can connect as many OCPN PC/Android you want and use the network UDP source and see all data connected to the first one. (Address 0.0.0.0 port 10112)
But for this you've to have charts for all PC/Androids. To use VNC one chart set for the first PC is enough.

[seandepagnier]

it was an idea i had a while ago but it is never implemented. You for now, simply run two instances of opencpn and route data as needed. For example linking both opencpn via a tcp connection, or linking both to a signalk server. Potentially have a gps on each one for redundancy is good anyway. Unfortunately, routes/waypoints/tracks are not linked.

you can use vnc which is clunky and only one instance is run.

avnav can do this though which has a completely different software architecture.

[AboutTime1]

Originally Posted by seandepagnier

avnav can do this though which has a completely different software architecture.

That is exactly how I would have designed a multiple client nav system.

Thanks for sharing the link.

[scargo]

VNC protocol is probably easier to deal with if you are a windows user.
However, if you are running OpenCPN on Linux, chances are that you know what X11 is. You can than send the DISPLAY to where you want and run multiple instances of OpenCPN on one computer. This would work as long as you have an IP network running in your boat.
Another possibility would be a hardware one: HDMI splitter. Your monitor on the chart table will be copied to the one at the helm. In my opinion, this is the simplest solution.

[AboutTime1]

Originally Posted by scargo

VNC protocol is probably easier to deal with if you are a windows user.
However, if you are running OpenCPN on Linux, chances are that you know what X11 is. You can than send the DISPLAY to where you want and run multiple instances of OpenCPN on one computer. This would work as long as you have an IP network running in your boat.
Another possibility would be a hardware one: HDMI splitter. Your monitor on the chart table will be copied to the one at the helm. In my opinion, this is the simplest solution.

VNC sucks for this sort of use case. As does the HDMI splitter and redirecting X11 output.

[Tupaia]

Why not just run three monitors. Control by touch screen or air mouse.

[requiem]

Depends a bit on how you want it to function. I prefer redundancy, and dislike having someone at one station changing the display on the others. E.g. if I'm working on a chart or radar down below, it shouldn't mess with the helmsman's display and vice versa. Of course, I'm also paranoid and consider VNC to add an unnecessary link of dubious reliability.

Thus I'd prefer separate systems that are able to synchronize data between them, such that if I create routes, add chart notes, etc on one system they are cascaded to the others.

This can get costly if you have to pay for charts though. Which reminds me, the last boat I was on had three B&G plotters, as I believe all can use a single chart card regardless of which of them has it inserted. This, along with data synchronization, would be useful for OpenCPN.

[AboutTime1]

Originally Posted by StuM

Something like TightVNC?
https://www.tightvnc.com/


Run it at the chart table and mirror it to a device at the steering station (can be a an Android tablet with Remote Ripple (same URL as above)).

This is why multi client applications should be designed with a true client server architecture.

[AKA-None]

Sorry I’m confused
Do you want mirrored displays or multiple independent displays
This has nothing to do with client server
Client server means you have a backend engine and a UI plus an app layer. Sometimes the UI and app layer are run on the same system but both can be considered client server just depends on how many tiers there are and if can be run independently (irrespective of where they are running)

[AKA-None]

Originally Posted by AboutTime1

This is why multi client applications should be designed with a true client server architecture.

Hmmm so mainframe apps don’t count as a multi user system? I assume that most people say client when they mean user or vs a vers

[AboutTime1]

Originally Posted by AKA-None

Sorry I’m confused
Do you want mirrored displays or multiple independent displays

Multiple independent displays.

This has nothing to do with client server
Client server means you have a backend engine and a UI plus an app layer.

Or a browser as the app layer.

Sometimes the UI and app layer are run on the same system but both can be considered client server just depends on how many tiers there are and if can be run independently (irrespective of where they are running)

Client-server is when there is a backend resource that provides services and data to multiple independent clients, just as the name implies.

[AboutTime1]

Originally Posted by AKA-None

Hmmm so mainframe apps don’t count as a multi user system? I assume that most people say client when they mean user or vs a vers

Mainframe refers to hardware. These days most users are actually clients. If you log in on a terminal or using something like ssh you are a user. If you connect with a browser, you are a client.

I mean client.

[Tupaia]

Originally Posted by AboutTime1

This is why multi client applications should be designed with a true client server architecture.

A couple of questions


How big is your boat?

How many navigators do you have on your boat?


Multiple operators of independent navigation systems that are properly integrated with an autopilot for example could result in disastrous consequences.


Just confused as to what your intended usage will be.