Need to expand data on RDP-148

[erikh]

So I need some help figuring this out. I have a RDP-148 display and dome radar. I want to get NMEA Output data for VHF and Yamaha gauges, eventually I’d be looking into getting an autopilot setup and possibly AIS etc.

Currently, the GPS antenna is hooked up to Data 1. PG1000 heading sensor hooked up to Data 2. Data 3 is empty. Data 4 is hooked directly to the DFF1. Somewhere along the line someone hooked the VHF Nmea to the PG1000 Nmea Port, which won’t work because that’s only sending heading data...

From reading up in the manuals it looks like Data 1 will give me NMEA Output, but the GPS cable is there. Is there a way to switch that GPS antenna cable to Data 3? Then buy a cable for Data 1 that I can tie NMEA into? Which cables would I need? I have the latest software installed for the RDP-148. Or, can the GPS antenna cable be converted so it can plug into a network hub? Also, can any network hub be used or must it be the Furuno box? Thanks!

 

[C-Bass]

Good afternoon Erikh,

Thank you for your inquiry.

I understand your troubles, Data Port 3 is explained as an RS232 data port so the voltage levels will accommodate a RS232 data signal.

If your radio can use a RS232 data signal you should be ok, if the radio only supports an RS422 voltage and signal then you will need to purchase a RS232 to RS422 data converter. That will be the safest way to achieve what you are trying to do.

C-Bass

 

[erikh]

Hi C-Bass. Thanks for the insight. So I can get an adapter from RS-232 to a NMEA cable, it looks like the Icom radio I have will take a RS232 signal. What Furuno cable do I need to get that will hook up to Data Port 3? I think then I just need to just the right lead from that cable or is there a RS232 connector on the end that I can just hook into an NMEA adapter?

 

[erikh]

So I’ve been going through the installation manual and it appears I need the 7P cable 000-154-028-10 to connect to Data 3. Can I just do NMEA0183 directly to the Yellow and Green of that cable? Please see the attached photo from the manual. Thanks!

 

[C-Bass]

Good morning Erikh,

Thank you for the info.

Can you provide the Icom radio model so we can double check to see if it is RS232.

The reason I bring this up, if it is not native RS232 their can be a different ground potential between 422 and 232 which can blow out the NMEA PCB on the RDP148 if an opto-isolator is not used. We want to verify.

But yes, if the radio is native 232, then you would use the White, Blue, and shield wire to interface with the radio.

Data Port 3: White-------------------------------->ICOM RS232 RX
Data Port 3: Blue---------------------------------->ICOM RS232 TX
Data Port 3: Bare Shield wire-------------------->ICOM RS232 GND


A 7-pin data cable is what you need. The part number you provided is no longer available. Please use this part number: 000-154-028. This is a 5m cable with a 7-pin connector on one end and bare wires on the other. You will use the bare wires to connect to the radio wires.


Kind Regards,
C-Bass

 

[erikh]

That’s C-Bass! The radio is an Icom M402 with NMEA + and - wires. I’d also be hooking it up to my Yamaha round gauges with their bare ended cable as well to get GPS speed.

 

[C-Bass]

Good morning ErikH,

Thank you for providing the model of radio. After investigation the ICOM 402 appears to use NMEA Version 2.0 with 2 wires for data input. Without calling ICOM we don't know for sure if their port is RS232 or RS422. My guess would be RS422 but it would be prudent to contact Icom to find out for sure. As mentioned before, if the Icom uses a common ground which has a different potential than the RS422 ground there is potential to blow out the NMEA port/driver on the radio or the plotter.

So depending on what Icom says you may need to purchase a RS232 to RS422 converter. If you have to go that route I would purchase a NMEA port expander that takes an RS232 input and can provide multiple RS422 outputs. When the RDP-148 is outputing at RS232 mode you are restricted to Single Talker/Single Listener. So if you have to take the data to (2) locations this may be needed.

Kind Regards,
C-Bass