Hopefully this will save others hours/ days of time.
Confirms this works for HD1024 and XT1144 players.
If using an LS424/5 player use Port 2. The documentation is wrong saying that the USB enumerates to Port 0 on these players using the USB-C to USB-A and 3.5MM Serial Out dongle. Also, the serial out of this dongle does NOT work at this time. But if you connect something like a Sabrent USB to DB9 Serial Adapter to the USB-A connection on the dongle then the LS424/5 will send out serial controls.
I recommend using screw terminal 3.5mm connectors, and BTX Technology screw terminal DB9 connectors. Commercially labeled serial cables are unreliable.
Please Note: PANASONIC PT-RZ Series projectors use a straight-through cable:
Rx to Rx / Tx to Tx / Gnd to Gnd
There is no need to short pins 7 & 8 or do anything else. Only these three conductors are needed. If you're using the 3.5mm output from the player, connect Rx to the TIP, Tx to the RING, and Gnd to the SLEEVE. On the DB9 connector to the projector (you'll need a DB9 MALE connector for the PT-RZ Series projectors) connect Rx to PIN 2, Tx to PIN 3, and Gnd to PIN 5.
For the BA Connected project:
PRESENTATION SETTINGS > CONNECTORS > SERIAL
PORT:
0 (FOR 3.5MM / PORT 2 FOR USB)
PROTOCOL:
BINARY
BAUD RATE:
9600
DATA BITS:
8
PARITY:
NONE
STOP BITS:
1
IN A PROJECT, ADD TO ANY ACTION/ EVENT HANDLER:
ADVANCED > COMMAND
COMMAND:
SEND > SERIAL BYTES (COMMA SEPARATED)
PORT:
0
BYTES:
2,65,68,90,90,59,80,79,78,3 [THIS IS FOR POWER ON]
2,65,68,90,90,59,80,79,70,3 [THIS IS FOR POWER OFF]
If this isn't working, confirm the Baud Rate is set to 9600 in the Panasonic projector menu settings.