Missing Heading Alarm on VX2 Network



In 2009 I removed my Mark-3 radar and GP-1850DF and went with a RDP148 (7” VX2) unit to run off of my existing RSB0071 radome. It became my chartplotter and radar. I also installed a PG500R heading sensor, NavPilot511 and FCV620 at that time. System worked flawlessly.

In 2012 I installed an RDP149 (10.4” VX2) in the dash and left the 7” overhead. Attached is my connection/network diagram. The system worked flawlessly most of the 2012 season. Towards the end of the season I intermittently received an alarm for missing heading data. The heading display on the radar screen would change to dashes. However, the navpilot LCD would continue to display proper heading at all times. My first thought was the cable from the pg500 AD10 to data 2 on the 7” so I bought another cable and proved it was not the cable. Both AD10 and NMEA from the PG500 would occasional result in the missing heading alarm. The 2012 season was cut short by Sandy.

The 2013 season started off with the same intermittent missing heading issue. After multiple sessions of on board diagnostics with Furuno phone tech support they recommended I pull the PG500 and send it into Camas, WA. I did and it proved to be functioning properly.

Per further review with Furuno phone tech support they feel that the data 2 port on the 7” is the problem and recommend that I send the 7” unit into Camas. I am not willing to give up my working radar until the offseason but will do then if needed. Right now I have a great working radar on the 7” for Heads Up only and no overlay.

As a work-around (and not shown on the attached diagram) I have re-routed heading to go from the PG500 AD10 port to data 3 on the 10.4” unit. This works fine for the 10.4” but when I turn on HDT to output over the network from the 10.4” to the 7” the heading locks up on both displays. I tried both AD10 and NMEA with same results.

Per review with Furuno phone tech support they say that you cannot send heading TO the Radar unit that heading must only come FROM the radar unit as part of the radar package. Seems odd though since the PG500 was originally connected to the 7” unit giving it heading. So what’s the difference between giving heading to the 7” direct from the PG500R versus over the network from the 10.4” unit which is now being fed by the PG500R? What am I missing here? Heading is heading, no? Is there anything else I can do or test shy of sending my 7" to Camas? I don't have another 7" unit to try, that would be nice..



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I don't see a problem with your workaround but I do have one question. You said you now have the AD10 information from the PG500 plugged into Data3 of the 10.4" RDP149 and you get good heading. Then if you turn on the HDT sentence on the "Output Through Network" menu selection of the RDP149 it locks up heading on both the 7" and the 10.4". Is there any chance you have the HDT, HDG or HDM sentence turned on in "Output Through Network" on the 7" VX2 display? I only ask this because you mentioned the lockup heading on both units. If you were to have HDT, HDM or HDG turned on from the 7" VX2 you would be creating a data loop that would cause a lockup. I would go into the 7" menu and turn off (or at least confirm they are already off) all "Output Through Network" sentences coming out of the 7" VX2 because in your current workaround there would be no need to have anything coming out of the 7" unit. The radar connected to the 7" unit will come out naturally across the network through IP address settings and naming conventions. Radar output is not affected by the "Output Through Network" settings. Your diagram shows the GPS is plugged into Data1 of the 10.4" unit and you told us the PG500 is now supplying heading to Data3 of the 10.4". Right now the only "Output Through Network" settings that should be "On" should be in the 10.4" unit only. Please let us know what you find.
Stickman":thk5kzhf said:
Is there any chance you have the HDT, HDG or HDM sentence turned on in "Output Through Network" on the 7" VX2 display?

Thanks for the reply. Yes, all sentences are turned off in the 7" Output Thru Network.

Stickman":thk5kzhf said:
If you were to have HDT, HDM or HDG turned on from the 7" VX2 you would be creating a data loop that would cause a lockup...

Yes I am aware of avoiding a data loop but interesting you mention HDM (Heading Magnetic)? I do not have that as an option on the 10.4" Output Thru Network, only HDT (Heading True). My AP and Radar is set for magnetic not true. Why would I not have an HDM sentence to turn on, just HDT and HDG?
Is there any followup to this? I have a very similar setup and am experiencing the same problem. Lower display is a 7" with GPS, Radar, Heading, and Network. Upper helm is another 7", 10", netgear switch with Depth, and Weather. Sometimes it works great sometimes not. Another message I posted it was suggested that I do hard reset and recalibrate. I did. worked great for a 4 hour trip. 2 days later Status and Auto go out and True comes on.
Nothing new. Still cannot send Heading to my 7" unit. So Heading goes direct to my 10.4" All this really comes down to is that I cannot display overlay on my 7" unit, no biggie, otherwise the system performs flawlessly. I may send the 7" unit into the service center this off season to see if they can determine why it will not accept Heading, either direct or over the network.
Maybe Furuno can shed some light on this.

I went out this past weekend and tried to re-calibrate the PG500. Started at shore by doing a hard reset, then a diagnostic with all displays off. All go with a solid STATUS. Turn on all displays and went out and turned circles calibration locked up with STATUS and CALB light solid for 5 minutes. Went to anchor for overnight.

Had to do another hard reset next day. Left all displays off except the lower 7" display that has all connections. Turned circles and this time it worked 4 lights flash and then it goes to STATUS and AUTO. Radar overlay looks great.

Go up to upper helm and turn on 10" display and select overlay and zoom in and it is askew. Go down stairs and the STATUS light is now flashing with AUTO solid.

One of the things I noticed is that the 10" display starts up with no chart and CSE UP North UP etc... between the 7" & 10" displays does not seem to show right on a overlay or has trouble figuring out which way is up so therefore the radar has trouble with orientation.

Anyone any thoughts???
Your issue is totally different than that of the tread you have posted to. His compass isn't having problems. His issue is related to a display problem that needs to be evaluated for repair. Much of his case history was accomplished on the phone directly with tech support.

Your issue is the heading compass itself. Your compass status light is flashing which reflects a compass error. Most cases when you see this, it is due to the placement of the compass. You can’t place it near big metal (including base where you are mounting it), speakers, or other electrical items that can affect the compass detecting magnetic north. It must be mounted flat with the bow mark forward and as low and close to centerline of the boat as you can. The PG500 has been around for about 10 years and we have sold many. It is a great compass but it is not water proof, not recommended for metal boats, and must be placed correctly. If you have tried other suitable locations and continue to get status light errors, then you might need to have the unit evaluated. I have seen cases where a customer’s docking area has large amounts of rebar in seawall or concrete enough to error a compass when near it. It is hard to say what you have going on but I can assure you that there isn’t an across the board issue with the product.

If you can’t narrow down the issue, I would recommend sending the unit into our factory service center for a full factory evaluation.
My 1833C get target very strong and clear but it has Heading data missing alarm continuously in recent days. I never seen this problem and I dont;t use heading sensor. Is there any way to stop it? I took my display to my friend's boat and I plug it to PG-500. the arlarm disapear.
Thank you


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