[CA] [CA11] A78 MFD temperature data source/anchor alarm

[toddster]

I have an A78 MFD installed with two sources of water temperature data: The sonar unit that came with it and an older ST40 speed/temp sensor on the SeaTalk1 interface. It seems that the ST40 has priority, but unfortunately, the sensor on that unit has failed. (It always reads 32°C!) If the ST40 instruments are turned off, then the correct temperature from the fish finder unit is displayed. Is there a way to make the fish finder the default data source?

One other unrelated problem is I get intermittent "anchor alarm max depth" alarms when under way, but I cannot find any place in the system where such an alarm has been or can be set?

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum toddster,

Q. Is there a way to make the fish finder the default data source?
A. Negative. With multiple water temperature sources, the following prioritization exists within MFDs running LightHouse II and LightHouse 3 software.

1. STng / NMEA 2000 Instrumentation
2. MicroNet Instrumentation
3. ST1 Instrumentation
4. NMEA0183 Instrumentation
5. SThs Sonar Modules (highest serial number taking priority)

It would be recommended that the speed/temp insert be replaced within the instrument transducer. Alternatively, the temp lead may be disconnected from the ST40 instrument.

[toddster]

The faulty transducer is an Airmar ST300-P371-HS The insert part number appears to be 31-256-1-42 rev.02, which I can't find on the web, but an entire new transducer ST300-P371 can be had for about the same cost as other inserts. Any known backward-compatibility issues? Or is this a part that might be available from Raymarine?

[Chuck - Raymarine - Moderator]

Todd,

Please click here to view a FAQ addressing transducer parts. As indicated therein, it is recommended that Gemeco be contacted for parts and for answers to the other related questions which you have asked within your last response.