POS Technical Documents
What does USB Hub and DM-D mean with Epson USB Connect-It Interface Cards?
The DM port allows you to connect an external Epson pole display.When the Connect-It interface card includes Type A USB ports, one can connect to these ports a scanner, MSR, keyboard, etc.
The Type A connectors are called "USB Downstream" ports as the data is going from the USB device "down" to the PC. The Type B connector is called a "USB Upstream" port as the data is going from the PC "up" to the printer.