[TG] [TG11] Can't connect to radome over Seatalk HS

[wbfooks]

My pair of Axiom 9 MFD's have lost connectivity to the radar radome. The radome is connected to a SeaTalk HS switch which also connects to the DM MFD. The port the radome is connected to on the switch has a green link light which blinks with activity, leading me to believe a) the radome has power, and b) there is good layer 2 link to the radome. The MFD can connect to other devices on the Seatalk HS network. Any ideas?

[Tom - Raymarine - Moderator]

Hello wbfooks,

Quote:a) the radome has power

Yes, it means that the radome has some power. Whether it's enough, and consistent enough, is another matter. Boats being boats, things tend not to stay in pristine condition for ever: terminals work loose, wires and connections become tarnished or corroded and what's at the battery is very often quite different from what reaches a product under load, and you'd likely get some activity on the HS5's port LED even if the supply was insufficient for the radar to power up fully.

Quote:and b) there is good layer 2 link to the radome.

Yes, this means that you have some form of traffic from the radar but this does not tell us anything about the reliability of that connection or whether traffic is being passed both ways. I don't think, for example, that your use of the word 'good' is necessarily merited: it doesn't take much to cause problems with 100Mbit ethernet in a marine environment, and you can get a flashing port LED on a network link which is too poor to pass a useful level of traffic reliably. The LED is proof-of-life, not of health.

I would suggest:

1. Measuring the supply voltage at the Modulator board connection point in the radar scanner, with everything connected and powered (that is, scanner's load applied to the cable) and with your multimeter set to record minimum voltage, and even then assume that the real minimum voltage is somewhat lower than is displayed since multimeters measure voltage relatively slowly and don't record brief dips well.
2. Using a Raynet-RJ45 adaptor cable and a standard bit of network cable to bypass the installed network cabling and connect between the HS5 or display and the radar's RJ45 socket on the IF board inside the dome, in case the problem exists in that cable run.
3. Since it sounds as if you're aware of a fair bit of background about ethernet, what I would be suggesting to one of our technical service dealers if they called for support on a job, or would be doing myself if I were aboard, is connecting the radar to my PC using a Raynet-RJ45 adaptor and using Wireshark to see what traffic, and two-way comms, I had with the radar. Only do this if you know what I'm talking about and know how to interpret the results; otherwise, get a Certified technical dealer involved.
   

The most likely cause of your symptom is that somewhere in the run of cabling you have a high-impedance connection in your ethernet or a voltage drop. Other than that you'd be looking at a radar fault and getting it back for Service.

Regards,
Tom