[DG] [DG11] AIS 700 with C80 and USB PC laptop connection.

[marlahe]

Hi. I just recently purchased an AIS 700. I previously owned an AIS 500 that worked flawlessly together with my C80 MFD and a PC with the COM port connection until the 500 suddenly decided to give up permanently. OK so life goes on and as I need the multiplexer function to connect my S3G autopilot heading datat (4800 baud) to the C80 I opted for the new Raymarine 700 with the SOTDMA protocol. Done deal. I connect the new AIS 700 exactly the same way as the 500 and with an USB cable to the PC. I program the AIS with all required data and everything seems to work perfect. That is until I shut off the PC! Then I lose a lot of targets on the C80, targets come and go and most of them display only the MMSI number. I may see some targets in a far distance but not the one just close ahed of me. As soon as I switch on the PC again everything goes back to normal on the C80. I don't need to start the ProAIS software or anything, just start the PC so the USB connection gets power. I have tried to disconnect cables, reprogrammed the AIS 700 but nothing helps. To see all AIS targetsI I need to constantly have the PC in sleep mood to "activate" the USB port. This is most annoying. We are currently on a circumnavigation and need to resolve this problem. Please assist.
Sincerely,
Lars Hellman

[Derek - Raymarine - Moderator]

Dear Sir,

As I indicated in my previous response, without a circuit diagram it is difficult to be precise, but it sounds likely that through your PC there is a ground loop that is affecting the data. the current products all confirm the the latest EU specs and it is possible you had not seen the issue in the previous unit due to a small change in the power system wiring or system interconnection.

Test with the PC completely disconnected from the ship's main power supply.

Regards
Derek