AIS data sentences are scrambled

[pendragon]

A couple of weeks ago my Matsutec HP-33A was working fine, outputting via rs232 to USB and also over WiFi, all working perfectly.
On starting it up yesterday, I don't get any useful data anymore.

i spend all day trying on 3 different laptops, running Xp, Win7 & win10.

Am not getting any ais data nor a GPS position.
Yet on the Matsutec screen, all AIS targets show. + it give a alarm when a ship is near. So the unit is working........yet no useful output

I also did a factory reset. It did not help

In Device manager the baud rate is set to 4800 and in Opencpn it is set to 38400

All logs show similar results as posted in the attached screen-print.
I have altered nothing on either the wiring not the AIS settings. I just tried out every setting I can find, but to no avail.


Can anyone please suggest a solution??

[hoolie]

Have you tried setting device manager to 38400 baud to match the rest of the system?

[Paul Elliott]

This doesn't look like a baud rate problem, since among the garbage you have a few more-or-less properly displayed NMEA sentences, and even more halfway-right ones. If the baudrates were truly mismatched than you wouldn't be seeing anything recognizable.

You mentioned USB and WiFi -- unless there is an actual serial-USB converter, a native USB connection isn't usually sensitive to baud rate settings, and a WiFi one isn't at all. What was the connection you used to get the screen you showed us?

[edit]
I just looked at the manual for the HP33-A, and it mentioned a USB connection as well as a physical serial port. Are you using USB or the serial port, connected to a serial-USB adaptor? If you are using the serial cable and want the HP33-A to send AIS data you need to set the unit's port speed to 38400.

Question to anyone that knows: Does OCPN control the serial port speed or do you actually have to set it in the Windows Device Manager? I think the OCPN setting overrides the Device Manager setting, but I'm not sure.

Anyway, it still doesn't look a port-speed setting problem.

[Marinetech]

This "garbled" data is usually cause by some sort of ground loop. Try using a opto isolator on the input to the PC.


Byron

[Paul Elliott]

Originally Posted by Marinetech

This "garbled" data is usually cause by some sort of ground loop. Try using a opto isolator on the input to the PC.

True, but if it was working before then something has changed. If the OP can figure that out he probably won't need the optoisolator.

I agree that it looks like a noise problem.

[pendragon]

You mentioned USB and WiFi -- unless there is an actual serial-USB converter, a native USB connection isn't usually sensitive to baud rate settings, and a WiFi one isn't at all. What was the connection you used to get the screen you showed us?

[edit]
I just looked at the manual for the HP33-A, and it mentioned a USB connection as well as a physical serial port. Are you using USB or the serial port, connected to a serial-USB adaptor? If you are using the serial cable and want the HP33-A to send AIS data you need to set the unit's port speed to 38400.

The screen print shown is from WIFI output, as CPN does not show any sentences, when connected via USB.
I think that it deletes or ignores false sentences and does not echo them. Seeing all are faulty, I get non displayed.



The matsutec output is wired to a DB9 connector, which plugs into a Serial to USB converter. I replaced this converter with a new one, but it does not make any difference (baud is set at 38400 in CPN)

I checked all the wiring and cannot find any faults nor dry solder joints.


And "Yes" I tried ALL the baud rates and all combinations of baud rate on 3 laptops (XP-win7-win10)

[Paul Elliott]

It sounds like the HP-33A is connected to the Yakker via a NMEA serial connection, and the Yakker is putting out the data over WiFi. Correct?

Does this same serial NMEA connection also go to the serial/USB adaptor? If so, disconnect that and just test using the HP-33A to Yakker connection, and monitor the WiFI.

If the data is bad then disconnect the Yakker and connect the serial/USB adaptor. There are other programs that will show you the raw serial data stream (such as PuTTY), use that to monitor the NMEA data.

Check the wiring in your connectors, too.

I'm trying to simplify the problem down to the bare minimum configuration. If that doesn't work and nothing else has truly changed then you probably have a bad Matsutec

OCPN will discard bad NMEA sentences.

[pendragon]

I tried all your sugestions... here are the results:

Putty output without WiFi and with USB connected shows the following.

On wifi only( no USB connected) it still shows the scrambled data, that I originally posted



With USB plugged (DB9 to USB converter) in it shows pages and pages of the following stuff::

▒7FM˥gYgSW.5.3.=>,;;-37,33=,6;.;5/3;-=7<-65,27.15/>39/37.39,77.3;6/4?▒7q▒˶G^GSW.5,4-==,3:-57,527.77.4:/37.3=5.35/67.99/975,5<-4?,;:-373/45+7s▒*▒gWgSW.5.5.1>/53.36/395/.5=/>;.3>1.▒7>▒▒G\GNO.376>/39536/S/576=>.72777,e,735553/<5,y,u*7F▒
$GXSMs.?37554/>?.M/376>/39536,S/176=7/7<>77.U,7/10:,5/82.=725==.,,V▒77▒+▒g^WTG.</28,U/.M/3/<>?.N/3/<>?.K/w+3>▒J▒GSGGy,>35557.07/3743.39=37.S/1761</7><77.E.:/9:/5.67.6/:.M-:7/3/M//27?9+7qM▒5gWgSM-}/3.<9,33.39,5>.3:,93.35/;2/9>/9=-33/4;/=.36/9.77.1.?5+7<▒˶gYGSV.5.=-1?,>1.39,34=/63,<3,57/;:5-45.5;.3;/741/6;.=9,92/36;-79*73ͪ▒gXGSV,5/:.1?/=;-=5,177.65-=6,76/=67/73/9?-33,3<7.61.;>,97,<38/37▒7v▒˶GXGSV,5-3/=>/:3.36/;;=,5<-:5,32/16;.79/:7,=5/7<9,37.35,77.326.7?▒7q▒▒5G^GSV,5-6-=9,3:/57,137,77,63/36.355/35.67.1>/>75/6;.7>/:3-?63.78▒7C▒▒6GYGSW.5.5,99/5?.36/3=5/.5=/<;.?>=.▒7:▒˶G^GNO/376>/39137/S,576=9.7>977.U,835557.?>/]/V▒7:▒ˡ}mWdM-1,=/-e/e>m9c?h\yz97V2];o93rM76k:t9ockk~mrWzV?9<>3sR=35Gksk^.4▒7d▒ ▒gTZMC/735555/?9,y,374;.3=937.S/=76=?/7><77,u/?/3>?/3.<7/94>599./-t*76͊4GTVVG/>.9<
▒GSGSV,5,5/9?.<9,3<.36=.43,73/16/:;5,51/1>/3;.<51/43/=9.=;/36?.71▒7:▒k'G\GSW,5/3/=;-=3,95/=72.76/=4-77,967/73.1?/33,29</45,:3/?7.>39/▒4gRGSW,5/3/=?.3:.37.;;=.49/;5/3;,1<?,71/37,=5.36=.36/39.77.3;5/6=*7

[Paul Elliott]

Originally Posted by pendragon

Putty output without WiFi and with USB connected shows the following.

With USB plugged (DB9 to USB converter) in it shows pages and pages of the following stuff::

▒7FM˥gYgSW.5.3.=>,;;-37,33=,6;.;5/3;-=7<-65,27.15/>39/37.39,77.3;6/4?▒7q▒˶G^GSW.5,4-==,3:-57,527.77.4:/37.3=5.35/67.99/975,5<-4?,;:-373/45+7s▒*▒gWgSW.5.5.1>/53.36/395/.5=/>;.3>1.▒7>▒▒G\GNO.376>/39536/S/576=>.72777,e,735553/<5,y,u*7F▒

This looks exactly like a baud rate mismatch, or possibly a data polarity reversal. NMEA signals are supposed to be differential, with (+), (-), and (GND) connections, so it's not that difficult to choose the wrong polarity when making connections to a single-ended RS232 adapter. But it looks like the Matsutec only has a single-ended NMEA data output (this is actually fairly common). If the Matsutec has a differential output, try connecting the opposite polarity signal to the RS232 adapter.

Originally Posted by pendragon

On wifi only( no USB connected) it still shows the scrambled data, that I originally posted

And that data didn't look like either baud rate or a polarity problem. More like a noise or buffer overrun problem.

So exactly what are the connections you are using for the WiFi test? I'm assuming you have the Matsutec connected to the Yakker via a serial connection (I see signal and ground for that on the Yakker), and then the Yakker is providing the WiFi. Is this correct?

You seem to have two different problems. There may be a single cause, but I can't think of one. Do you have any other NMEA source you can connect to the Yakker or your serial/USB adaptor?

[pendragon]

The setup was and still is:
The Yakker is outputting data over WIFI.(which was working before)
The i/o from my HP-33A is ONLY possible to rs232, there is no direct USB i/o possible, except using a serial to USB converter. hence I soldered a DB9 plug to the ouput cable, using RX and Gnd to pins 2 & 5 of DB9.

When the USB converter(to laptop) is disconnected from the DB9 plug, Yakker output is the same as in the green screenshot originally posted.
When the Yakker is removed, the USB converter shows data in Putty, as posted in a earlier post.
When both are connected at the same time, both outputs remain the same.
This means that the wiring in not at fault.

The HP-33A screen is showing AIS targets and sounds alarm on possible collision.
The unit works,BUT the output is useless, while some weeks before all were working fine? I did not physically change any wiring..

I don't have anything else that outputs (connectable to wire) NMEA data.
The baud rate in Device manager for the USB converter is set to 4800 and in CPN on 38400 on Com9 (AIS setting as per manual )

I did do some welding using a HF start tig welder, on the hull, but I kept the earth clamp as close as possible the the weld area (steel boat).
I have used this welder before and the HP-33A kept outputting data as usual without any problems.
Maybe the HP-33A has developed a fault due to multiple welding jobs or old age, after 4 years of service ??

[pendragon]

I just fired up the Yakker again and the serial -USB converter is completely disconnected.
In the NMEA debug window i am getting readable data, but CPN does not show a position not any AIS targets are on the list. What I do get is shown in the attached screenshot.
Does this make sense to anyone?[IMG]C:\Users\T61Win7Pro\Desktop\image001.png[/IMG]

[nohal]

Originally Posted by pendragon

I just fired up the Yakker again and the serial -USB converter is completely disconnected.
In the NMEA debug window i am getting readable data, but CPN does not show a position not any AIS targets are on the list. What I do get is shown in the attached screenshot.
Does this make sense to anyone?[IMG]C:\Users\T61Win7Pro\Desktop\image001.png[/IMG]

All the sentences visible in your seemingly "readable data" on the picture are corrupted.

[Paul Elliott]

One more time to make sure I understand: How is the HP-33A connected to the Yakker? Two wires from the HP-33A output to the Yakker NMEA input?

The Yakker WiFI to OCPN case shows corrupt data, but at the correct baud rate.

The HP-33A to USB adaptor to PuTTY looks like a baudrate problem. This could also have corrupt data -- we can't tell.

I still think you have more than one problem. The corrupt data could be caused by a damaged HP-33A. If you can fix the baudrate problem you may be able to tell if the HP-33A is OK or not.

I'm surprised that I don't see any AIS sentences in the readable screenshots. The baudrates need to be set to 38400 in order to carry AIS.

[pendragon]

2 wires--> YES 1 data line (green) 1 earth )black. The baud rate is set to 38400 in CPN and 4800 for the serial - usb converter, as per manual.
I used CPN versions 3.... and the latest --> all show the same problem
It was all working a few weeks ago, with these settings and wire connections and also Yakker output to any tablet ,phone or laptop.

As you mention probably a failty HP33A . Over the 4 years i had it , it has been in use for about 7 months .

[smac999]

Check the baud rate setting in the ais itself. If The output of its changeable. Both those pics is gps data only. (Though bad data) No ais data . Which would happen if the ais was outputting in 4800 instead of high speed. That is how the vesper works anyways.


Plug the ais directly into a computer serial port or USB converter. and use something like hyper terminal to view data. (Built into xp) That last pic it’s coming through an IP address not a com port. . Get back to basics. Ais to pc direct via com port .m

Ais data is AIVDM and AIVDO

The rmc and gga is gps info.