Texas Instruments TI-73 Explorer User Manual page 20

Communication Error
This error indicates that the TI™ Connect software ("Unable to
communicate with device") or TI-GRAPH LINK™ software ("Link
Transmission Error") is unable to communicate with the
calculator. The problem is usually associated with the
TI-GRAPH LINK cable and its connection to the calculator or to
the computer.
• Make sure the cable is firmly inserted in the calculator link
port and the computer.
• Verify that the correct cable type is selected in the software
link settings.
• Verify that the correct communications port (Com Port) is
selected in the software link settings.
If this does not correct the problem, try a different
TI-GRAPH LINK cable and restart your computer.
TI-73 / TI-83 Plus Logic Ladder Page 20