Sounder issue

[RussH]

Hi,

I have MFD12 units onboard and a DFF1 fed by a P79 transducer. Depth also displayed on an FI50 display. On start up all seems to be working and depth is displayed. But then after a short while all depth info appears to stop and does not return. Next time it’s all powered up same happens. Hull is clean. Usually occurs after getting underway.

Anyone else experienced similar symptoms. If so how was it resolved?

Where should I start? Do I need a new transducer?

Thanks.

 

[Johnny Electron]

It almost sounds like the symptoms of having a data loop issue. Is the P79 the only transducer on the boat? Does the FI50 have a NMEA smart depth sensor as part of the 2000 network?

 

[RussH]

It almost sounds like the symptoms of having a data loop issue. Is the P79 the only transducer on the boat? Does the FI50 have a NMEA smart depth sensor as part of the 2000 network?

Hi. Thanks for responding. Really appreciate the help.

The P79 is the only transducer. Boat is fairly new to me and I’ve no previous experience of Furuno gear so any thoughts are gratefully received.

Russ.

 

[Johnny Electron]

If the only source of depth is the DFF1/P79; then I recommend you run the setup wizard and check that no one has checkmarked DEPTH as an input to any of the NMEA ports in the setup. There should be none of the ports with depth checkmarked. Then go to global - data sources at the top of wizard setup and ensure that your depth pull down is selected for DFF1, then save and exit. When the unit comes up go to the sounder screen and ensure you have set the sounder to AUTO RANGE and AUTO CRUSING modes. This should help the sounder keep depth on the screen even when not looking at the sounder. Your depth shouldn't drop out any longer.

 

[RussH]

If the only source of depth is the DFF1/P79; then I recommend you run the setup wizard and check that no one has checkmarked DEPTH as an input to any of the NMEA ports in the setup. There should be none of the ports with depth checkmarked. Then go to global - data sources at the top of wizard setup and ensure that your depth pull down is selected for DFF1, then save and exit. When the unit comes up go to the sounder screen and ensure you have set the sounder to AUTO RANGE and AUTO CRUSING modes. This should help the sounder keep depth on the screen even when not looking at the sounder. Your depth shouldn't drop out any longer.

Thank you. Boat not launched until first week in April. So I’ll try this when she’s afloat again and see how I get on.

 

[RussH]

Thank you. Boat not launched until first week in April. So I’ll try this when she’s afloat again and see how I get on.

If the only source of depth is the DFF1/P79; then I recommend you run the setup wizard and check that no one has checkmarked DEPTH as an input to any of the NMEA ports in the setup. There should be none of the ports with depth checkmarked. Then go to global - data sources at the top of wizard setup and ensure that your depth pull down is selected for DFF1, then save and exit. When the unit comes up go to the sounder screen and ensure you have set the sounder to AUTO RANGE and AUTO CRUSING modes. This should help the sounder keep depth on the screen even when not looking at the sounder. Your depth shouldn't drop out any longer.

Launched and tried your advice. Unfortunately it made no difference. I have noticed though that the data cable from the DFF1 is not a shielded one. Not sure if that may make much difference. But I’ve ordered up a shielded one and will replace it.

Would the next stage be to replace the transducer?

Thanks.

 

[Johnny Electron]

The P79 uses fluid that tends to slowly disappear and should be serviced. Have you ensured the unit is full of fluid and point to the correct angle to the bottom?

 

[RussH]

The P79 uses fluid that tends to slowly disappear and should be serviced. Have you ensured the unit is full of fluid and point to the correct angle to the bottom?

I’ll check that next when the current storm we‘re experiencing here in Cornwall has passed. I’ll keep you posted. Thanks.

 

[Magnetron]

Usually occurs after getting underway.

Definitely follow all the maintenance procedures listed in the Airmar Owner's Guide and Installation Instructions. I noticed in the last line you write, "Usually occurs after getting underway." This could indicate loose wire, loose fitting in the NMEA bus. Or it could indicate what's written in the Airmar guide's useful section on "Placement" where it cautions installers to choose locations where the fiberglass is SOLID (no air bubbles are trapped in the fiberglass resin). Further it notes, If you have a cored fiberglass boat and there is no reading or it is erratic, the transducer may be positioned over [coring/something] which is absorbing the acoustic energy.

Check NMEA2000 fittings, power tees and connectors otherwise Choose another location for the P79.

That's what I would advise,

ref.: https://www.airmar.com/uploads/InstallGuide/17-217-01.pdf

- Maggy

 

[RussH]

Definitely follow all the maintenance procedures listed in the Airmar Owner's Guide and Installation Instructions. I noticed in the last line you write, "Usually occurs after getting underway." This could indicate loose wire, loose fitting in the NMEA bus. Or it could indicate what's written in the Airmar guide's useful section on "Placement" where it cautions installers to choose locations where the fiberglass is SOLID (no air bubbles are trapped in the fiberglass resin). Further it notes, If you have a cored fiberglass boat and there is no reading or it is erratic, the transducer may be positioned over [coring/something] which is absorbing the acoustic energy.

Check NMEA2000 fittings, power tees and connectors otherwise Choose another location for the P79.

That's what I would advise,

ref.: https://www.airmar.com/uploads/InstallGuide/17-217-01.pdf

- Maggy

Thank you. I’ll also take a look at this.

 

[Magnetron]

Let us know what you find out. I've found for a lot of these 'depth' and 'temp' issues that we often run into, the DST-810PSF really helps alleviate the problem as a dedicated sensor.

- Maggy

 

[RussH]

The P79 uses fluid that tends to slowly disappear and should be serviced. Have you ensured the unit is full of fluid and point to the correct angle to the bottom?

Hi Johnny,

Finally got to check this. Fluid appeared ok. Looked like mineral oil. Still replaced it with the recommended glycol. No change unfortunately. I see that the transducer is connected to a 9m mix & match cable to the DFF1. Ive wiggled connectors etc and again no change.
Seems that there's some kind of intermittent signal\interference getting through to the MFD.
Thinking that the next stage is a new transducer? Any views on which one or same one gratefully received. Perhaps one not using the mix n match cable would be better?

Thanks again for suggestions so far.

Russ.

 

[RussH]

Let us know what you find out. I've found for a lot of these 'depth' and 'temp' issues that we often run into, the DST-810PSF really helps alleviate the problem as a dedicated sensor.

- Maggy

Thank you. See my reply to Johnny Electron. I'll also look into your suggestion. Will this just plug direct into the DFF1?

Russ.

 

[Magnetron]

Thank you RussH,

While underway, do you hear any aeration around the hull in the transducer area? Is it a stepped hull? At the dock it function normally -- but as soon as your vessel moves and creates some aeration, it doesn't? Cavitation from a prop, or aeration may explain the odd behavior.

- Maggy

 

[Johnny Electron]

Looks like you have lots of extra cable. When running the transducer in your hand, can you hear the clicking? (normally put the sounder on dual freq). If the cable is long enough, have you tried holding it over the side of the boat and try to keep the angle right to get a good bottom? Why is there so much cable? Transducers normally shouldn't have cables longer than 66 total feet. Anything beyond that will start to hurt performance until it plum won't work.

 

[RussH]

Looks like you have lots of extra cable. When running the transducer in your hand, can you hear the clicking? (normally put the sounder on dual freq). If the cable is long enough, have you tried holding it over the side of the boat and try to keep the angle right to get a good bottom? Why is there so much cable? Transducers normally shouldn't have cables longer than 66 total feet. Anything beyond that will start to hurt performance until it plum won't work.

The cable is a Mix and Match https://www.airmar.com/uploads/SpecApps/airmaremea_mixandmatch_cable_12x18_poster_MR.pdf It's effectively an adapter cable to enable a generic transducer to connect to the Furuno DFF1 and quite normal if not ideal I think.

 

[RussH]

Looks like you have lots of extra cable. When running the transducer in your hand, can you hear the clicking? (normally put the sounder on dual freq). If the cable is long enough, have you tried holding it over the side of the boat and try to keep the angle right to get a good bottom? Why is there so much cable? Transducers normally shouldn't have cables longer than 66 total feet. Anything beyond that will start to hurt performance until it plum won't work.

No clicking heard. Im going to bite the bullet and get a new transducer and see what happens.

 

[RussH]

Thank you RussH,

While underway, do you hear any aeration around the hull in the transducer area? Is it a stepped hull? At the dock it function normally -- but as soon as your vessel moves and creates some aeration, it doesn't? Cavitation from a prop, or aeration may explain the odd behavior.

- Maggy

Dont' think its this issue as its in a suitable area. I'm going to bite the bullet and get a replacement transducer. Its not working at all now.

 

[Johnny Electron]

If you don't hear clicking or feel a little tickle when the face of the transducer is sitting on your hand, something is definitely wrong. Let us know how it turns out.

 

[Magnetron]

For depth, the simplest solution likely would be the DST-800PWF Transom mount. However if you want to stick with an in-hull solution, we also have the 235-IHF In-Hull Digital Depth Sensor. Otherwise the the DST-810 is one of the more recent favorites for external depth.

- Maggy