True heading AIS CTRX

[Masjaf]

I am wiring a True heading AIS CTRX Class B transponder to a Quark-Elec A034 NMEA multiplexer. The multiplexer calls for a RS-422 wiring. In the AIS manual, and I have attached a screenshot of the page, the relevant wires as I understand it are Orange and Black.
Orange being called TXA (-),
Black being called TXB (+)

I am a bit confused because normally the TXA would be + and TXB would be -. So, reading from the A034 multiplexer manual, I have first tried connecting the Orange to IN3 + and the black to IN3 -, then Orange to IN3 - and black to IN3 +. The IN3 port is by default set to 38400 baud rate and I checked that. There are no filters.

The led for IN3 port on the multiplexer never blinks and there is no AIS NMEA data received on the laptop, neither VDM nor VDO sentences, which is connected over wifi to the multiplexer. Other NMEA2000 sentences from other devices are coming through without problem. I have no other NMEA0183 devices wired to the multiplexer.
There is a pilot boat that is transmitting AIS data right next to the boat, the AIS transponder LEDs are showing normal operation and marinetraffic.com is also showing a few cargo ships in the port in addition to mine, so there are AIS talkers in the vicinity and AIS is being transmitted from my boat.

My next step is to try and find the adapter to USB to connect the transponder to the computer although as I read from the manual, there is no configuration that I can do. Can anyone check if my wiring is correct or is there something that I am missing? Any other tips on how to troubleshoot this problem?

 

[Masjaf]

I have found another manual online that has a slightly different wiring diagram. The Orange TXA is + and the black TXB is -.

 

[Masjaf]

I have solved the issue. Just in case anyone else needs to know here's the solution.

It turned out that the Orange wire was TXB and it went to NMEA IN -. Black wire was TXA and it went to NMEA IN +. The real problem lay in the AIS for some reason transmitting the NMEA data at 4800 baud rate. Using the ProAIS software downloaded from True Heading website, I connected the AIS to the computer and set the baud rate to 38400. Everything worked afterwards.