Raymarine STng troubleshooting & cable testing

Conflicts between data sources can show symptoms of a SeaTalkng communication error. When the system has more than one source for any type of data, it is necessary to ensure that the Data Sources function has been used to specify which resources should be used by the system for each type of data (GPS, Wind, Depth, etc.) where two or more sources exist in the system. Therefore, it is recommended to first verify that the Data Sources function has been used correctly before proceeding with troubleshooting obvious SeaTalkng communication errors (NO AIS, NO FIX, etc.). Additionally, if the system has an AIS350, AIS650, or AIS500, it is recommended to verify that the AIS350, AIS650, or AIS500 has only been connected via one communication protocol (i.e., either SeaTalkng (preferred) or NMEA 0183, but not both).

If the points about Data Sources and AIS receivers/transmitters above have been met and a SeaTalkng communication error persists, it is recommended that the vessel's batteries be fully charged and the problem duplicated after charging and while connected to shore power. If the problem cannot be duplicated under these conditions, the problem may have been caused by insufficient power, and it is recommended in such cases to address the power issue through one or more of the following actions:

• The vessel's batteries are load tested and replaced depending on the results of the load tests,
• Additional house battery storage is added to the vessel,
• The vessel's charging system is used more frequently,
• The vessel's charging system capacity is increased.

If the problem can be duplicated while connected to shore power, it is recommended to verify the following:

The backbone is inspected for:

• Correct termination,
• That the SeaTalkng backbone's power input spur has been placed at the approximate midpoint of the SeaTalkng backbone's LEN load.
• If a SeaTalkng backbone power input spur has been installed and a Raymarine Evolution ACU200/400 or SPX10/30 autopilot course computer has been installed, that the ACU or course computer's SeaTalkng POWER switch has been configured to the OFF position. Note: it is considered best practice for the SeaTalkng backbone to be powered via a power input spur (e.g., T-piece, 5-way connector spur).
• Maximum total spur length (6m) is not exceeded,
• No more than 3 devices daisy-chained within a spur,
• Correct joints,
• Signs of cable damage (cuts, kinks, crushing, etc).

Check the resistance of the backbone's two termination plugs... the measured resistance across its CAN_H and CAN_L pins should be 120 ohms.

With the backbone turned off and one of its two termination plugs removed, check the resistance of the backbone across the CAN_H and CAN_L pins in the backbone socket that had its termination plug removed to verify that it is 120 ohms... if not, remove devices one by one until it is determined which device is causing the resistance to be unexpected... if any such device is identified, send it to Raymarine's product repair center for bench testing/service.

With the backbone turned off, replace the previously mentioned termination plug in its backbone socket and then remove the other termination plug. Check the resistance of the backbone across the CAN_H and CAN_L pins in the backbone socket that had its termination plug removed to verify that it is 120 ohms... if not, remove devices one by one until it is determined which device is causing the resistance to be unexpected... if any such device is identified, send it to Raymarine's product repair center for bench testing/service.

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