[CA] [CA11] Erratic depth readings with DST800 and TackTick instruments

[closereach77]

Recently installed an Airmar DST800-P617V triducer, which runs to a TackTick T121 hull transmitter, and then through the network (C95 plotter, various TackTick displays, autopilot).

The speed data and all other instrument data is reliable, but the depth data is highly erratic. In any 5 second period, I will get multiple depth numbers, most of which are 100+ feet higher than than the actual depth, with an occasionally accurate number thrown in. Doesn't seem to matter weather I'm sailing, motoring, or at a mooring.

Any ideas?

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum closereach77,

The Raymarine products are simply designed to repeat data from NMEA 2000 and NMEA 0183 sources. Accordingly, should the communications interfaced of the NMEA 2000 or NMEA 0183 Airmar smart transducer be monitored, I suspect that you will find that the depth information specified by the system is mirroring that which is being transmitted from the transducer's NMEA 0183 or NMEA 2000 communications interface. If so, and the transducer's identification tag is branded with a Raymarine part number, then please respond with photo of the transducer's identification tag which clearly shows all information printed on the tag. Should this be a Raymarine transducer and should the system feature no other sources of depth information, then it may indicate a transducer which has been fouled with marine growth or has failed. However, should the transducer only bear Airmar labeling, then it would be recommended that Gemeco, Inc. (Airmar’s US distributor (803 693 0777)) be contacted for troubleshooting information.

[closereach77]

Thanks Chuck. Image of by DST tag attached here. One note from further troubleshooting on Friday:
My instruments (basically just a T121 plus all the wireless displays) are on one breaker, and my MFD (a c95 HybridTouch) is on a separate breaker. If my MFD is NOT powered up, the depth data on the instruments displays perfectly. As soon as I turn on the MFD, I start getting the erratic data.

Maybe that helps shed some light on the issue.

[Chuck - Raymarine - Moderator]

closereach77,

Thanks for the additional information. The transducer is a TackTick T910 triducer. Has the MFD been interfaced to a fishfinder sounder module? Should latter be so, then it is quite possible that the ping of the fishfinder transducer is interfering with the TackTick T910. Turning the ping OFF within the MFD's Fishfinder application or configuring the Fishfinder to ping at 50kHz instead of 200kHz (the frequency used by the T910) would eliminate any interference. You may also want to check the MFD's Data Sources feature to verify that the TackTick system has been configured as the system's source of Depth data.

[closereach77]

Chuck,
I got on the boat yesterday to do this. Turned on the instruments only (no plotter) and monitored the depth reading for 10 minutes or so while doing some other things. It was consistent/accurate.

I then started the engine...and immediately started getting erratic readings again. Engine off, and the readings became accurate.

Ugh! Any other ideas? I have not checked data sources on the MFD yet, thinking that might be a red herring in light of the above.

Thanks.

[Chuck - Raymarine - Moderator]

closereach77,

Should the system function correctly when only the marine electronics are powered ON and then fail when the engine(s) are running, then the reported issue is likely being caused to electrical noise from the engine system. There are a number of third party marine power conditioners available in the marketplace to address such issues. That said, I would typically recommend getting a Certified Raymarine Installer onboard to advise on the problem and possibly suggest / install a power conditioner.