There is a new dual serial I/O board for the updated Honeywell PX4 industrial printer, the PX4ie. The part number is 50147018-001 and it is currently shipping. Unlike the old board, which was dual RS232 out of the box, you need to install two jumpers and two IC (integrated circuit) chips into the board.
You are working with static sensitive devices here, so make sure you ground yourself before touching the board or ICs.
For UART A the jumper connects the two pins on the right of P4 and the IC gets installed in the socket pictured here. Notice the semi circle on the bottom of the chip (it’s clearer on the next picture), it lines up with the semi circle on the board:
UART B installs the same way:
Again, note the semi circle cut out at the bottom of the IC. This time the jumper is installed at P8. Make sure that you don’t bend any of the pins on the IC when you insert it into the socket.
The rest of the installation is described in the Honeywell installation manual. Click on the documents tab to get this manual.