Microcom 438 Operator's Manual page 44

Chapter 3 Getting Started
You would connect to the printer using the active port. The example above shows that the
active port is the USB port, so connect to this port and send the appropriate command to
enable ethernet use.
Sending a ^A1^D108 would set the printer to the 2 Port Autoselect between the USB or the
XPORT Ethernet port.
Sending a ^A5^D108 or ^A6^D108 command would set the printer to either use the
Microcom Ethernet Option board or to the 3 Port Auto Select (Serial, USB, or Microcom
Ethernet).
438 Operator's Manual - 880052-0103 3-27