2020-04-05, 07:00 PM
Since you want to only receive from the Garmin depth sounder and transmit to the VHF, you can possibly use the same converter. RS422 is a protocol based on differential signal; if all devices actually use the wire pairs you should be Ok and could just try it out.
But possibly you don't fully use those differential wire pairs. In that case it's more like an RS232 connection. That can work just fine between OP, Garmin and VHF. You do need to make sure that all these device are grounded properly.
Of course, the baudrate of all three devices need to be programmed to match.
Alternatively, you get yourself a separate serial<->USB converter. I myself apply simple/cheap RS232<->USB converters, and make sure all devices are properly grounded. E.g.:
https://www.amazon.com/JANSANE-PL2303TA-...ics&sr=1-2
(BeerCanSailing on hold due to Corona virus)
But possibly you don't fully use those differential wire pairs. In that case it's more like an RS232 connection. That can work just fine between OP, Garmin and VHF. You do need to make sure that all these device are grounded properly.
Of course, the baudrate of all three devices need to be programmed to match.
Alternatively, you get yourself a separate serial<->USB converter. I myself apply simple/cheap RS232<->USB converters, and make sure all devices are properly grounded. E.g.:
https://www.amazon.com/JANSANE-PL2303TA-...ics&sr=1-2
(BeerCanSailing on hold due to Corona virus)