Correction...dislike posting incorrect info...pin 4 & 6. 5 is blank on the later cable.
And IIRC the Furuno weather station (rebranded Airmar) WS200 has stuck to the early system
of a pin & terminating resistor in the WS activated by a pin in slot 5 on the head unit.
Mods, please correct me if I am wrong here.
It seems Furuno & Airmar must have collaborated on this.
Also if you could clarify if the WS2- C30 cable is compatible with the WS200/ early PB200?