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Raymarine forum - AIS 650 - STNG Output Not Working, NMEA Does.

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My AIS 650 suddenly stopped talking via STNG to my E-140 Widescreen, and started showing the AIS as “OFF” on the sensor status bar. It boots up fine, shows an amber light and then a steady green light (normal). The Diagnostics / External Interfaces / ST NG, shows no devices active, although there is packet activity (perhaps from a ST GPS feeding ST NG through an adapter?)

I’ve swapped out the ST NG spur cable, no change. I disconnected the STNG cable, hooked up the NMEA bi-directional connection, and the AIS now works, but only at NMEA 4800 baud, and not at AIS 38400. I have updated the AIS software to 1.15.01 via SD card, and the ProAIS software shows this version and Port 1 set to 38400.

Questions: Is this a Software or a Hardware glitch? In the AIS or the display? Can I just hook up AIS IN to the #3 NMEA 0183 port on the E140 at 4800 baud (and save a bi-directional port) and what would I lose in using 4800 baud and in not having AIS OUT back to the AIS? Most importantly, can I trust the AIS unit's reliability in the future, or should it be returned and repaired?
Welcome to the Raymarine Forum Wimpress,

Q1) Is this a Software or a Hardware glitch?
A1) Based upon the information provided, one or more of the following may be responsible for reported issue:
- failure to interface the MFD and AIS650 to one another via a powered and properly terminated SeaTalkng backbone
- the SeaTalkng bus is not powered (verify that the SeaTalkng bus has been powered form a switched 12 VDC power circuit located at the approximate mid-point of the backbone's LEN load)
- early software within the AIS650 (should the AIS650's software have been updated prior to disconnecting the AIS650 from the SeaTalkng backbone, then this may be ruled out)
- failure of the MFD's SeaTalkng port (should other devices which have been interfaced to the SeaTalkng backbone be communicating with the MFD, then the MFD's SeaTalkng port would be deemed to be operational)
- failure of the AIS650's SeaTalkng port

Q2) In the AIS or the display?
A2) See the response above. Fault isolation may be performed by interfacing the MFD to another compatible device having a SeaTalkng communications interface.

Q3) Can I just hook up AIS IN to the #3 NMEA 0183 port on the E140 at 4800 baud (and save a bi-directional port)?
A3) Doing so will prohibit the MFD from controlling the AIS650's Silent Mode state.

Q4) What would I lose in using 4800 baud and in not having AIS OUT back to the AIS?
A4) Due to the high volume of data associated with communications of AIS data, Raymarine's AIS recievers, as well as those of most other manufacturers, exclusively support NMEA 0183 communications at 38400 BAUD.

Q5) Most importantly, can I trust the AIS unit's reliability in the future, or should it be returned and repaired?
A5) Should the AIS650 still be within it warranty period, then it is recommended that it be serviced prior to the end of its warranty period. That said, failure of the AIS650's SeaTalkng communications circuitry (assuming no other damage the AIS650) should have not effect upon its NMEA 0183 communications.
A couple of clarifications to my original post and a couple of questions:

1) My STNG network is minimal - currently only a ST1-STNG converter to bring in GPS data, the spur to the AIS, and a spur to the MFD. It continues to carry the GPS data to the MFD, so I assume all is well with the network.

2) I can live without control of the AIS Silent Mode.

3) Assuming the STNG port on the AIS has indeed failed, why does its NMEA port also appear affected (limited to only NMEA 4800)? The AIS Installation Manual refers to "High Speed" and "Low Speed" ports, but does not identify them specifically as Port 1 or 2. I assumed the "High Speed" port is Port 1 on on the ProAIS configuration page, and set #1 at 38400 and #2 at 4800. Could this be a factor?

4) Will using 4800 baud transfer of AIS data really be noticed in the real world?

5) As before, the concern is whether or not the unit as a whole has been damaged or can be trusted as reliable.

Thanks for all help.
Wimpress,

As the MFD is receiving GPS data via its SeaTalkng communications interface, you can indeed assume that the the MFD's SeaTalkng communications interface is operational and the SeaTalkng backbone is powered. However, it does not necessarily mean that the SeaTalkng backbone is properly terminated. A backbone which has not been properly terminated backbone may yield partial or intermittent communications. Accordingly, it is recommended that you verify that the SeaTalkng backbone has been properly terminated with a SeaTalkng Termination plug or SeaTalkng Inline Terminator at each of the backbone's two end nodes.

Q3) Assuming the STNG port on the AIS has indeed failed, why does its NMEA port also appear affected (limited to only NMEA 4800)? The AIS Installation Manual refers to "High Speed" and "Low Speed" ports, but does not identify them specifically as Port 1 or 2. I assumed the "High Speed" port is Port 1 on on the ProAIS configuration page, and set #1 at 38400 and #2 at 4800. Could this be a factor?
Q4) Will using 4800 baud transfer of AIS data really be noticed in the real world?

A3 / A4) You appear to have an incorrect understanding of the AIS650's NMEA 0183 ports. As configured at the factory, the AIS650's Port 1 is configured for 38400 BAUD NMEA 0183 communications and its Port 2 is configured for 4800 BAUD NMEA 0183 communications.
- The AIS650 is designed to multiplex data received via its 4800 BAUD NMEA 0183 input port - Port 2 (ex. 10Hz heading data, DSC VHF radio reports, multiplexed 4800 BAUD NMEA 0183 data, etc.) with NMEA 0183 AIS sentences and then transmit the combined data stream at 38400 BAUD via the AIS650's Port 1.
- Additionally, the AIS650 is designed to transmit data received via its 38400 BAUD NMEA 0183 input port - Port 1 (ex. GPS data, navigational data, instrument data, etc.) at 4800 BAUD via the AIS650's Port 2.

When interfaced in the manner specified above, this capability essentially provides the system with an additional bi-directional 4800 BAUD NMEA 0183 communications port. The AIS650/350/500/250's 4800 BAUD NMEA 0183 Port - Port 1 is most commonly used support bidirectional VHF radio communications within systems having a limited number of NMEA 0183 ports.

AIS receivers must communicate at the high data rates supported by 38400 BAUD NMEA 0183 or NMEA 2000 communications protocols to ensure sufficient data communications bandwidth to support the high bandwidth requirement of AIS data communications.

Q5) As before, the concern is whether or not the unit as a whole has been damaged or can be trusted as reliable.
A5) As indicated within the prior response, failure of the AIS650's SeaTalkng communications circuitry (assuming no other damage the AIS650) should have not effect upon its NMEA 0183 communications. Accordingly, should your AIS650 be interfaced to the MFD via NMEA 0183 communications as specified above and your MFD then be observed to be receiving AIS data, then can be assumed that the AIS650's NMEA 0183 Port 1 communications circuitry is operational. Similarly, should your AIS650 be interfaced to the MFD via NMEA 0183 communications as specified above and your MFD then be observed to be receiving data from a 4800 BAUD NMEA 0183 device or be observed to be providing data to 4800 BAUD NMEA 0183 listener, then can be assumed that the AIS650's NMEA 0183 Port 2 communications circuitry is operational.
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