[CA] [CA11] a95 MFD connected to AirMar P79

[Chuck - Raymarine - Moderator]

Ted,

To recap our phone conversation, the Diagnostics…html file which you had sent to me earlier today must have been created when only the a95 MFD’s circuit had been energized as it did not list any of your system’s other devices. During our phone conversation, the entire suite of electronics was energized and then instructions were provided to once again display the MFD’s Select Devices list (HOME->SET-UP->MAINTENANCE->SELECT DEVICES). Upon executing the specified command sequence, the Select Devices List not only listed the MFD, but also all three components of the Evolution autopilot (p70, ACU, & EV-1), proving that the Raymarine system was functioning properly and supporting SeaTalkng / NMEA 2000 communications. Unfortunately, the Airmar branded P79 Smart Transducer was not listed among these devices. Should the technician who had installed the Airmar branded P79 Smart Transducer onboard the vessel determined that the transducer was neither being detected by the Raymarine products nor providing depth to the system, then the installer should have interfaced a NMEA 2000 analyzer to the system (ex. Actisense NGT-1 & PC with NMEA Reader software, etc.) to the backbone. Upon doing so, the technician should have then been able to determine whether the Airmar branded P79 Smart Transducer was indeed communicating via the backbone and if so, determine what information was being transmitted by the Airmar branded P79 Smart Transducer to the backbone.

These symptoms would typically indicate a problem with one or more of the following:
- a problem with the cable assembly which is interfacing the Airmar P79 to the system’s SeaTalkng / NMEA 2000 bone
- a failure within the Unfortunately, the Airmar branded P79 Smart Transducer's SeaTalkng communications circuity
- total spur length exceeding the 6m maximum specified for SeaTalkng / NMEA 2000 spurs
- a failure of the spur socket of the T-Piece or 5-Way Connector which the Airmar branded P79 Smart Transducer has been connected to.

The only further recommendations that I may offer with regard to troubleshooting would be to:
- trace the P79's cable back to the 5-Way Connector or T-Piece that it has been connected to and to ensure that it has been connected to a spur (white) socket in one of these networking components.
- attach a label to the P79's cable, identifying that this cable is going to the P79. It would be a best installation practices to similarly label the other spur cables which have been connected the backbone's T-Pieces and 5-Way Connectors to assist in any further troubleshooting.
- ensure that the total length of the P79's cable and cable or adapter which has been connected to its cable does not cause the total combined cable length to exceed 6m.
- inspect the field installable DeviceNet plug which had been installed onto the transducer's cable. If the field installable DeviceNet plug is from Maretron, then information concerning the plug may be found here.
- verify that the spur socket into which the p79's cable is operational. This may be accomplished by unplugging the P79's cable from the spur socket within the 5-Way Connector or T-Piece that is connected to. The Spur cable from one of the system's other devices may then be unplugged from the socket within the 5-Way Connector or T-Piece to which it is presently connected and then plugged into the spur socket which hand been occupied by the p79's cable. The MFD's Select Devices list diagnostic feature would then be used to verify that the displayed list included Evolutions autopilot devices (p70, ACU, & EV-1). If so, then the spur socket previously used to connect the p79's cable would be deemed to be operational. If not, then the spur socket would be deemed to to not be operational.

Should each of the above have been verified, then it would appear that the Airmar branded P79 Smart transducer has suffered a failure of its NMEA 2000 communications circuitry and the transducer should be replaced.

The information which you had provided indicates that a field installable DeviceNet plug (presumably manufactured by Maretron) had been fitted onto the bare wire leads of the Airmar P79 Smart Transducer to then permit a SeaTalkng Spur to DeviceNet Adapter Cable to be mated to the Airmar P79 transducer’s cable assembly. The SeaTalkng to DeviceNet Spur Adapter should have then been connected to a spur socket (denoted by white locking ring) within one of the backbone’s T-Pieces or 5-Way Connectors. The easiest way to resolve the situation may be to simply replace the Airmar branded P79 transducer with the Raymarine branded P79S Smart Instrument Transducer (Raymarine Part #T70278) shown below, as our product support team is not equipped/trained to support troubleshooting third party devices beyond that which has been rendered to date.

The Raymarine branded P79S Smart Instrument Transducer (Raymarine Part #T70278) features a 6m cable with a plug (no bare wires) and simple plug to plug adapter to permit the transducer to be directly mated the backbone spur socket which the Airmar branded P79 transducer’s cable had been mated. Replacing the transducer should be a simple matter of
1) Removing the Airmar branded P79 Smart transducer from its housing
2) Verifying that the transducer reservoir has been filled to the proper level with RV antifreeze
3) Installing the Raymarine branded P79S transducer into the Airmar P79 transducer’s housing
4) Chasing the Raymarine branded P79S transducer’s cable to the backbone’s T-Piece or 5-Way Connector which the Airmar branded P79 Smart transducer had been connected
5) Installing the SeaTalkng Adapter onto the Raymarine branded P79S transducer’s cable
6) Unplugging the Airmar branded P79 Smart transducer from the backbone’s T-Piece or 5-Way Connector
7) Plugging the SeaTalkng Adapter into the available spur socket (white) within backbone’s T-Piece or 5-Way Connector
8) Securing the locking ring of the spur socket (white) into which the Raymarine branded P79S transducer’s cable has been connected.

NOTE: The total length of cable employed within the creation of a spur should not exceed 6m. In this case, should the transducer’s cable not be sufficiently long enough, then the backbone will need to be extended to close the distance gap between the transducer and the currently installed backbone. Should additional detail be required, please click here to view the FAQ addressing this subject.

Unfortunately, Raymarine, Inc. cannot sell products, including transducers, directly to the end users. Instead products must be purchased from an authorized Raymarine dealer. The good news that the street price of the Raymarine T70278 P79S Smart Instrument Transducer is much less than the $1000 which you had suggested during our phone conversation. West Marine lists the Raymarine T70278 P79S Smart Instrument Transducer for $349.99. It is recommended that this transducer be purchased or that continued support be sought through Airmar / Gemeco in troubleshooting the Airmar P79 Smart Transducer’s NMEA 2000 communications failure. Information concerning the wiring for Maretron's field installable DeviceNet plugs may be found here. If Airmar is providing another brand of field installable connector, then it is recommended that Airmar or Gemeco be contacted for information on the connector.