It has 5V power supply on USB connector for charging your PNA. It also converts TTL levels of serial communication to RS232 levels suitable for PNAs.
On one side there is a 5pin USB mini B connector. Use this to connect to your PNA. On other side there is 6-pin RJ11 cable. You should connect this to USER port on LX Era.
Note: Some PNAs (e.g. Vertica) are using 10 pin USB mini-B connectors. Use 5-pin to 10-pin extension cable which is usually supplied with the PNA device.
USB mini B pinout:
Pin 1 = +5V
Pin 2 = RX
Pin 3 = TX
Pin 4 = +5V
Pin 5 = GND