TBay_Sailor

Nexus NX Depth sounder malfunction

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I just installed a legacy Nexus NX Seadata display connected via a WSI box to a triducer which is an Airmar DST800V (speed, depth and temp).  I bench tested prior to install and speed/temp worked but was unable to test depth since it was out of the water.  After installation today, all I see for depth readings on the Nexus SeaData instrument are dashes.

Anyone have any ideas as to what might be the problem?

Thanks

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The only thing I can suggest is that you check to see that you have sensible entries in C14 and C15.

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How is the DST800 connected to the WSI box?  (Which pins on the box did you use?)

There are various types of DST800s out there so a bit hard to help without more details.

- I generally thought DST800 today were mostly NMEA 0183 or NMEA 2000, and I thought the Nexus WSI box does not have connection pins for NMEA (without a Nexus server) so i’m not even sure how the speed connection is happening.

- On the other hand, if you have an old DST800 that is analog I imagine you connected it to the speed/depth pins on the WSI box. In that case check the specs of your DST800 - Nexus specifically requires 200khz depth input - as far as I can tell the current DST800 are 235khz output, so that could be your problem right there. 

Knowing how finicky the Nexus systems are to proper wiring, my first guess is a wiring/pins issue or kHz incompatibility issue. 

 

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8 hours ago, jarcher said:

The only thing I can suggest is that you check to see that you have sensible entries in C14 and C15.

Yes I tried that.  C14 I tried different units to no avail.  It won't let me adjust the offset (C15) at all - just shows dashes on that screen too.

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4 hours ago, galacticair said:

How is the DST800 connected to the WSI box?  (Which pins on the box did you use?)

There are various types of DST800s out there so a bit hard to help without more details.

- I generally thought DST800 today were mostly NMEA 0183 or NMEA 2000, and I thought the Nexus WSI box does not have connection pins for NMEA (without a Nexus server) so i’m not even sure how the speed connection is happening.

- On the other hand, if you have an old DST800 that is analog I imagine you connected it to the speed/depth pins on the WSI box. In that case check the specs of your DST800 - Nexus specifically requires 200khz depth input - as far as I can tell the current DST800 are 235khz output, so that could be your problem right there. 

Knowing how finicky the Nexus systems are to proper wiring, my first guess is a wiring/pins issue or kHz incompatibility issue. 

 

The system I'm using was pulled from a working boat and the previous owner claims it worked fine when pulled.  The wires are color coded to the WSI box so unless there's a color mismatch, connection should be straightforward.  My understanding is that the depth functions are the blue and black wires (see pic).

I believe the WSI box is NMEA 0183 but the manual doesn't say.  It does state:  "The depth transducer is connected to pin 6-8 on the WSI box. Note, only 200kHz transducer can be used!"

So you're right about the 200 KHz issue.  I'm not sure of the KHz of the transducer.  I'll have to check on the boat.  I did try hooking up another transducer to the WSI box yesterday (I just hung it over the side of the boat in the water).  This transducer is 200 KHz and it did not give me a reading either.

2018-05-21 11.06.01.jpg

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6 hours ago, galacticair said:

How is the DST800 connected to the WSI box?  (Which pins on the box did you use?)

There are various types of DST800s out there so a bit hard to help without more details.

- I generally thought DST800 today were mostly NMEA 0183 or NMEA 2000, and I thought the Nexus WSI box does not have connection pins for NMEA (without a Nexus server) so i’m not even sure how the speed connection is happening.

- On the other hand, if you have an old DST800 that is analog I imagine you connected it to the speed/depth pins on the WSI box. In that case check the specs of your DST800 - Nexus specifically requires 200khz depth input - as far as I can tell the current DST800 are 235khz output, so that could be your problem right there. 

Knowing how finicky the Nexus systems are to proper wiring, my first guess is a wiring/pins issue or kHz incompatibility issue. 

 

This combination is sold as a set, the Seadata instrument, WSI Box and triducer. Most likely the original owner bought it that way.

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Can you give u a pic of the display as the system starts, where the firmware version is displayed?

There is a way to reinitialize the display, although I'm not optimistic that will help. I think its you hold the C button as you power up, or maybe it's the set button.

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11 hours ago, jarcher said:

Can you give u a pic of the display as the system starts, where the firmware version is displayed?

There is a way to reinitialize the display, although I'm not optimistic that will help. I think its you hold the C button as you power up, or maybe it's the set button.

OK so long story short is:

1) I verified that this is a 200 KHz triducer

2) Plugging the WSI box into two other transducers known to be working did not show depth on the Seadata screen - only dashes

I attached a pic of the display at startup.  Yes, I tried re-initializing but no joy there.

From this I conclude that the WSI box is probably defective in some way.  Anyone have experience with WSI boxes crapping out?

 

 

2018-05-27 17.22.20.jpg

2018-05-27 17.23.11.jpg

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One last thing to try: grab a multimeter and measure the voltage on pins 6-8 (probably 6-7, but also check 6-8, 7-8).  I’m not sure what you should read but see if you have any signal. If there’s a signal then I agree probably the box crapped out. Have seen that happen on Nexus servers, very similar problem (blank reading) but for the wind transducer.  We tried replacing the wind transducer first, no luck, then replaced server and it all worked.

You may also be able to find the expected voltage for a 200khz transducer with some googling to reference against what you see on the multimeter. 

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1 minute ago, galacticair said:

One last thing to try: grab a multimeter and measure the voltage on pins 6-8 (probably 6-7, but also check 6-8, 7-8).  I’m not sure what you should read but see if you have any signal. If there’s a signal then I agree probably the box crapped out. Have seen that happen on Nexus servers, very similar problem (blank reading) but for the wind transducer.  We tried replacing the wind transducer first, no luck, then replaced server and it all worked.

You may also be able to find the expected voltage for a 200khz transducer with some googling to reference against what you see on the multimeter. 

I just realized you already tried known good transducers so checking the voltage with a multimeter probably won’t help.  Sounds like the box died indeed. They seem to break (at least partially) ever so often, so i’m not surprised. 

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13 hours ago, galacticair said:

One last thing to try: grab a multimeter and measure the voltage on pins 6-8 (probably 6-7, but also check 6-8, 7-8).  I’m not sure what you should read but see if you have any signal. If there’s a signal then I agree probably the box crapped out. Have seen that happen on Nexus servers, very similar problem (blank reading) but for the wind transducer.  We tried replacing the wind transducer first, no luck, then replaced server and it all worked.

You may also be able to find the expected voltage for a 200khz transducer with some googling to reference against what you see on the multimeter. 

OK so I tried putting a voltmeter on all the combinations of pins 6, 7 and 8 and none of them read any voltage at all (this was with the known good transducer plugged in).  Not sure what to infer from that.  What does the "screen" wire do anyway?

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10 hours ago, TBay_Sailor said:

OK so I tried putting a voltmeter on all the combinations of pins 6, 7 and 8 and none of them read any voltage at all (this was with the known good transducer plugged in).  Not sure what to infer from that.  What does the "screen" wire do anyway?

I read up some more via Google and that actually sounds fine -- I was thinking you'd get a pretty clear, consistent voltage like with a speed or wind transducer, but apparently for depth it's quite different.  The server sends very brief voltages through the transducer and measures the response delay to calculate depth -- all of this is too short for a multimeter to truly read.  So my suggestion was not really helpful.

All I could suggest now is to find someone else with a Nexus server or WSI box and try connecting your known good (or actual) depth sounder into that to see whether that system reads any data.  My guess is you'll find your problem is in the WSI box.

jarcher knows his Nexus stuff, so see if he comes back with any other suggestions.

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On 5/27/2018 at 9:19 PM, TBay_Sailor said:

OK so long story short is:

1) I verified that this is a 200 KHz triducer

2) Plugging the WSI box into two other transducers known to be working did not show depth on the Seadata screen - only dashes

I attached a pic of the display at startup.  Yes, I tried re-initializing but no joy there.

From this I conclude that the WSI box is probably defective in some way.  Anyone have experience with WSI boxes crapping out?

The display startup looks okay, with ID 16 which is correct.

Based on the fact that you tried other, known good transducers, I would have to agree that the WSI box is likely defective. However, can you connect your triducer to another WSI box that is known good? If so do you get a depth reading? Usually, the DST800 is easily removed from it's housing so you can bring it to another boat. Once you have verified that the triducer is good with another WSI box, it would be reasonable to condemn your WSI box. 

I'm still checking one more resource so don't give up just yet. 

 

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6 hours ago, jarcher said:

The display startup looks okay, with ID 16 which is correct.

Based on the fact that you tried other, known good transducers, I would have to agree that the WSI box is likely defective. However, can you connect your triducer to another WSI box that is known good? If so do you get a depth reading? Usually, the DST800 is easily removed from it's housing so you can bring it to another boat. Once you have verified that the triducer is good with another WSI box, it would be reasonable to condemn your WSI box. 

I'm still checking one more resource so don't give up just yet. 

 

I plan on testing the triducer on another boat that doesn't have a WSI box but does have a NX2 server which should be adequate for testing purposes. 

If the WSI box is at fault, does anyone know where these can be acquired?

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Not sure where you can get a full box, but someone is selling the PCB on Ebay:

https://www.ebay.com/itm/Nexus-Instrument-Various-Parts-Spares-Select-from-drop-down-menu/322122704036?hash=item4b000264a4:m:mBC5k83pT5hyk6yiK1sD-KQ

No idea how hard it would be to replace the PCB though, but I imagine it's reasonable.  May require some soldering, you can probably check your existing PCB.

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would it be possible to wire the depth transducer into a receiver from another manufacturer, such as Raymarine and then wire that into the NMEA Nexus system?

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On 6/3/2018 at 12:32 AM, TBay_Sailor said:

would it be possible to wire the depth transducer into a receiver from another manufacturer, such as Raymarine and then wire that into the NMEA Nexus system?

No. The depth sounder needs a depth amplifier which is built into the servers and WSI boxes. If you could find a compatible system with a depth amp that emits NMEA0183 then you could do it, but check your PM and get back to me. 

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