In order for Electronic Technician to work with the Communication Adapter II, you must change the Settings to select the Caterpillar Electronic Technician as your Communication Interface Device:
Step 1 Start Caterpillar Electronic Technician
Step 2 Press the “Stop Connect” button when it appears
Step 3 Select the “Settings” menu (or the “Utilities” menu with Car Scanner Tool ET 2001A or later)
Step 4 Choose “Preferences…”
Step 5 Select the “Communications” tab
Step 6 Change the Communication Interface Device to SIP
Step 7 “COM1″ should be selected. This application firmware only supports Serial communications.