Lowrance HDS: Sharing System Changes Over Networks

[jimh]

In an other discussion about NMEA-0183 interfacing, PORTHOLE describes some unusual behavior between two Lowrance HDS units in which a change in the serial port settings on one HDS device was migrated to other HDS devices:

It took several back-and-forth attempts with the network port setting pages and even turning one unit off while adjusting the other, but eventually each unit kept its respective baud rate, and the Icom has data.

That is odd behavior. If you adjust the serial port speed setting on one HDS device, you would not expect that the new setting would migrate and be applied to other HDS devices. How are the two HDS devices interconnected? Are they on another network? A NMEA-2000 network? An Ethernet network?

[porthole]

NMEA 2000 network; Ethernet cable direct between the units; and, if wireless has anything to do with it, both are on the same WiFi network.

And I forgot, NMEA 0183

[porthole]

There are multiple settings on the HDS Gen3 that will change in both units if adjusting either device.

For example, setting the number of engines, fuel tanks and fuel tank size instantly reset the settings on the other unit.

[jimh]

NMEA 2000 network; Ethernet cable direct between the units; and, if wireless has anything to do with it, both are on the same WiFi network.

I forgot about the WiFi network option. That is a lot of interconnection between devices!

[jimh]

There are multiple settings on the HDS Gen3 that will change in both units if adjusting either device. For example, setting the number of engines, fuel tanks and fuel tank size instantly reset the settings on the other unit.

That is because those settings are actually NOT ON EITHER device. You are setting up the FUEL DATA MANAGEMENT SENSOR or formerly called the DATA STORAGE MODULE. When you set up this external device on one HDS, it changes the settings of the external device. Then, when you connect to that external device with the second HDS, you see the settings on the external device have changed. None of those settings or the stored data is actually on either HDS.

[jimh]

There is a good presentation from Lowrance that originated in the dawn of the HDS series that explains what data is carried between devices on what network connection. The presentation is actually a series of slides in a PowerPoint presentation, and it is called HDS SYSTEM OVERVIEW. The file used to be hosted by Lowrance at their main website host, but it is no longer there. You can find it at other hosting sites. Here is a link:

http://lowranceprostaff.dk/download/low ... erview.pdf

If you read this document, you will find a chart showing a matrix of data and networks. It will have a line for AIS and indicate that AIS is shared over NMEA-2000 networks. But, as I mentioned earlier, that is really a bit misleading because AIS data does not originate in the HDS. If there were HDS data on a NMEA-2000 network, then, of course, that data would be available to other HDS devices on the NMEA-2000 network as well as to the first HDS device.

The chart does mention two categories, "Data source settings" and "System settings" as being shared over Ethernet. You might try an experiment. Disconnect one of the HDS devices from the Ethernet. Then change the settings on the other device for its serial ports. Then check to see if the HDS that was not on Ethernet had its settings for the serial port changed. This would tend to confirm that the change in serial port settings was migrating via Ethernet.

[porthole]

There is a good presentation from Lowrance that originated in the dawn of the HDS series that explains what data is carried between devices on what network connection. The presentation is actually a series of slides in a PowerPoint presentation, and it is called HDS SYSTEM OVERVIEW. The file used to be hosted by Lowrance at their main website host, but it is no longer there. You can find it at other hosting sites. Here is a link:

http://lowranceprostaff.dk/download/low ... erview.pdf

If you read this document, you will find a chart showing a matrix of data and networks.

There are at least two differences on the above matrix.

1) Backlighting - display brightness is synced between the two units. You can tap the power button multiple times and each display will step through the four preset brightness levels. Or tap the power button once and use the the brightness slider on the screen for infinite adjustments. Also, one display can be at max and one at minimum brightness. Tapping the power button more then once or accessing the slider will sync both displays to equal brightness.

Side note, setting one display to night mode does not sync the second display.

2) I have a Navionics+ card on HDS #1. That chart software is available on HDS #2

[jimh]

Yes, there is evidence that some system settings like LANGUAGE or BACKLIGHT ILLUMINATION can be changed via network for multiple devices in synchronism. But I am skeptical about the serial port settings. I asked some other Lowrance HDS users with multiple HDS devices to check on this, and they reported findings that contradict Duane's.

Duane--please double check your observations with and without the units linked by Ethernet.

I would test this myself, but I don't have two HDS units here.

I also wonder if the version of NAVICO OS software is an influence.

What also makes me skeptical is that notion that the shared setting could be overcome by just turning off one unit when setting the other. If the settings were intended to migrate, you would think they would do just that as soon as one unit jointed a network with another unit already there.

Also, what establishes which unit is the master and which is the slave? Or is any unit that changes a setting always the master?