Stand Alone RS130

I am attempting to interface a RS130 to a vYacht WiFi Multiplexor
This is outside of the boat as I wanted to test it was working before installation.
The boat has an existing ST1 network of knotmeter, compass, depth, compass.
This first attempt is from my Living Room so no other instruments are currently available.

Step 1 - The RS130 is connected to a E22158 STng -> ST1 convertor.
Powered up. No other connection. Attached image shows connections

RS130 flashes Red/Orange indicating it is unable to communicate with the STng buss.

Is this because there is no other equipment currently connected to the network?

Will the GPS only broadcast when it sees other devices on the network?

Step 2 - I powered the E22158/RS130 through the ST1 port. This freed up one of the STng ports to interface to the multiplexor via its NMEA2000 input.
No Signal was detected.
This could be explained by the errors I am seeing in Step 1 but wanted to see if there could be any other cause.

Any insight greatly appreciated.

  RLRS130STNGTOST1toseatalkinasystem.jpg (Size: 21.75 KB / Downloads: 1)