Possible problem and solution:

The VW3L3P01R40 cable has a five-volt DC input, which should be used if intermittent or no communication is encountered.
Use a 5 VDC regulated power supply with at least 50 mA current.
The power jack is for a 2.5 mm diameter plug center polarized connector.

Be sure to check the baud rate set in Lexum CT, and be sure it is the same as the Lexium ILP/ILT baud rate setting.