Texas Instruments TI-83 Plus Manual Book page 102

Communication Error
This error indicates that the TI Connect™ software ("Unable to
communicate with device") or TIGRAPH LINK™ software ("Link
Transmission Error") is unable to communicate with the
TI83 Plus. The problem is usually associated with the
TIGRAPH LINK cable and its connection to the TI83 Plus
and/or to the computer.
• Make sure the cable is firmly inserted in the calculator I/O
port and the computer.
• Verify that the correct cable type is selected in the TI Connect
or TIGRAPH LINK link settings.
• Verify that the correct communications port (Com Port) is
selected in the TI Connect or TIGRAPH LINK link settings.
If this does not correct the problem, try a different
TIGRAPH LINK cable and reboot your computer. If you continue
to get this error, please contact TICares™ Customer Support
for assistance.
TI-83 Plus CellSheet™ Application Page 102