Denso Intelligent Tester IT2 Communication Errors (Solved)

Just purchased $285 Denso Intelligent Tester IT2 V2015.07 for my 2011 Toyota RAV4 from Shipped for 5 days, items including the main unit Denso Intelligent Tester IT2, some cables and three cards in a plastic box.
I am new to diagnosis, and have some puzzles at beginning. Connection with vehicles is a big headache for me. But luckily, I have succeeded in it. And today, I post here for sharing with you.

When I use the Intelligent Tester II , this communication error below displayed.
Denso intelligent tester-communication error
Denso intelligent tester-retrieving error
With the help of the technician of wobd2 and the user manual, I deal with it as follows:
1. Touch [OK] at the top right of the error message window. This closes the window and returns to the head screen of the function in which the communication error occurred.
2. Turn the vehicle ignition switch OFF.
3. Turn the Intelligent Tester II power switch OFF. A connection defect for the datalink cable may be the cause of a communication error. Check the datalink connector (DLC 3) connection at the Intelligent Tester II and vehicle sides.
4. I restart the Intelligent Tester II, and no the communication error occurs again.

Hope it help you also.

Note: according to the technician, if the communication error occurs again, have a try to connect the Denso Intelligent Tester IT2 to another vehicle of the same model and check if a communication error occurs with that vehicle.
If no communication error occurs, there may be a problem with the vehicle. Inspect and repair the vehicle as necessary, in accordance with the vehicle repair manual.
If a communication error occurs, there may be a problem with the Intelligent Tester II.