CDU Qty
Set this to the number of CDU's you have attached to your PC.
Comm Port & Baud Rate
Set this to the comm port and baud rate for the relevant CDU (the Windows device is Silicon Labs CP210x USB to UART Bridge). The CDU itself needs its baud rate configured to match (Press EXEC + S on the CDU).
Position
Choose which aircraft CDU the device is to be attached too.
Emulation
Firmware - the CDU runs as per its setting designiated in the firmware of the unit.
CDU737 - the CDU acts like a 737 unit.
CDU747 - the CDU acts like a 747 unit.
Disconnect Timeout
The time in milliseconds the interface waits for an "alive" message from the CDU before considering it disconnected.
Timeout Threshold
The number of times communication has failed to the CDU before considering it disconnected.
Never Disconnect CDU(s)
Having this option ticked will stop an Interface restart if the status of any of the attached CDU's changes from OK.
Display Delay Time
The CDU screen data is pushed into the interface in waves (a quirk of the PMDG SDK). To enable a smooth screen update, a delay is introduced to stop the display updating in waves. PC's faster than an i5 4.7Ghz may be able to lower the setting from default 100 milliseconds whilst slower PC's may need to increase it.
Text Styles
PMDG aircraft make use of colour CDU's. Various text styles can be used to mimic the text styles of the PMDG aircraft. Not all text styles work with all CDU's.