GP33 PC connection


Furuno Super Fan
Could someone shed some light on the interconnection of a PC (RS-232) with a RD33. I got the special cable but the documentation is not clear to me. I expected to see to equivalence of:


But the doc says:


Could someone help me establish the equivalence please :respect
The RD33 uses a RS422 NMEA 0183 and the PC connection on the RD33 uses a RS232 NMEA 0183. It is VERY important that the device you are using is designed to convert the one standard to the other. You could damage something if you “Jump” standards without a proper conversion. I don't want to blindly provide guidance that might cause you problems. Do you mind providing some details about the "Special cable" you are attempting to use? I am sure I can help, but I need a bit more info to work with.
Thanks Johnny
Hi Johnny,

I am so sorry i wanted to meant GP33. I have an RD33 for display but i am using the GP33 to drive all my ICOM radios with the gps position. This i why i want to connect the GP33 to both the ICOM 602 and the ICOM802. Those radios are RS232. I'm sure the GP33 support RS232 because the documentation says so. I am using the cable 000-156-405 Power cable Assy FCV585 FCV620 to which i have cut the fuse cables (red and black) as documented.

Thanks for your help ! :respect
The IC-602 and IC-802 are RS422 to the best of my knowledge. We always connect them to them to the GP33 White (+) and Blue (-) NMEA 0183 wires. Both radios can connect to this one output but NOTHING more. Radios tend to pull more current than a standard NMEA listener so that output is maxed out, once you put these on. (Your RS232 output is still open for 1 suitable RS232 device) If you need to run more RS422 devices (like a plotter) from the GP33; you would require a NMEA expander (amp). Your connection to the radios would look like this.

White (+) output to ---> IC602 NMEA IN (+) AND IC802 NMEA IN (+)
Blue (-) output to -----> IC602 NMEA IN (-) AND IC802 NMEA IN (-)

Hi Johnny

Thanks for the information. Agreed there would be no more than 2 radios connected to the GP33. I would also need to know which wire to use to send the DSC information from the radio to the GP33 (only from one radio = the ICOM 602).

These are the yellow and green wire; which one is the NMEA OUT+ and NMEA OUT-

thanks !
The GP33 is a GPS not a plotter, so it will not accept DSC information from your radios. The Yellow and Green wires are part of the RS232 communications port designed for a Serial PC connection. The input part of the RS232 connection is ONLY for inputting waypoints and routes from a suitable PC software package. You should strap these wires back and not use them unless wiring up a PC/RS232 connection.
Hi Johnny

Oups this is bad news, i tought the GP33 could do the NMEA0183 conversion of the DSC sequence and put it on the NMEA2000 network. My navnet diagram has been validated by the dealer and probably this as passed unnoticed. So from what you say i should rather use the MFD12 NMEA0183 serial interface to complete that function.

Thanks for straightening the subject ! :sail

When you wire the DSC to your MFD, you do NOT need to put any checkmarks for the input of the data in your setup. DSC will automatically be seen by the system when wired properly at the same baud rate. I just wanted to let you know, because some customers have been looking for a DSC block to checkmark for the input port.