i70 - Sea Temp with Merc Gateway

[psubill78]

Setup: A12, CPT-120 transducer, Merc Gateway (2 engines). Multiple i70 displays.

When the merc gateway is powered up - I lose the sea temp on the i70 units. Shows the incorrect data from the merc gateway (as there is no transducer supplying the data).

When I turn off the engines, the i70 shows the sea temp from the CPT-120.

On the a12, there is a data called Environment/Water Temp that shows the transducer data the whole time, regardless of if the engines are on or not.

The i70 doesn't have a water temp, nor an ability to select the water/sea temp source.

I suspect this is a NMEA duplicate data issue. I can't find any setting to resolve - but hoping there is one :)

Thank you

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum psubill78,

As you have suspected this is a NMEA duplicate data issue. By default, the instrument will utilize data from lowest instance number. In this case, the NMEA 2000 PGN containing the water temperature data which is being transmitted by the Mercury NMEA 2000 gateway contains a lower NMEA 2000 instance number than that transmitted by the Raymarine MFD. While Raymarine MFDs provide a Data Source selection feature to a address systems where more than one source of a specific type of type of data, sea water temperature is not presently among the data items for whih a source may be selected. The MFD is displaying the temperature associated with the fishfinder transducer, because it is the master source.

A feature suggestion has been submitted to consider the addition of sea temperature to the Data Sources selection feature of Raymarine's a/c/e/eS/gS-Series MFDs and i70 Multifunction Instrument Displays.

[psubill78]

What is most interesting, it seems the a12 has the ability to display either variable:

Environment/Water Temp exists on the a12 - which shows proper CPT120 data. If you pick sea temp - it would show the inaccurate value of the SmartCraft. However, Environment/Water Temp does not exist on the i70. Hopefully an easy fix to this (feature request) would be to have that variable on the i70 units.

Given SmartCraft is pretty common for interfacing into the NMEA2k network, are you aware of any workaround that folks have used? I am guessing since the Merc gateway is a 'dumb' device - there is no configuration I can do there to stop that data from being sent.

[Chuck - Raymarine - Moderator]

psubill78 ,

Q: Given SmartCraft is pretty common for interfacing into the NMEA2k network, are you aware of any workaround that folks have used? I am guessing since the Merc gateway is a 'dumb' device - there is no configuration I can do there to stop that data from being sent.
A: No. Temperature source selection within Raymarine products would primarily be targeted at systems which feature more multiple water temperature sensing transducers as is common when more than one fishfinder sounder is installed within the system. From a NMEA 2000 purist's standpoint, a NMEA 2000 product should not be transmitting PGNs for which no sensor data has been provided. Correspondingly, as the Mercury Marine system has no water temperature sensing transducer interfaced to it, then it should not be transmitting the PGN including water temperature. Seeking to solve the problem by changing the i70's software is in effect recommending that Raymarine produce a software workaround for a problem within a third party product rather then seek a correction within the third party product itself.

[david.caron@videotron.ca]

Same situation as listed here but with a different PNG

http://forum.raymarine.com/showthread.php?tid=777

[Chuck - Raymarine - Moderator]

David,

Thanks for the additional input.