Canon C2050 Service Handbook page 279

E711
Main cause The DADF/editor has an IPC communication error.
Condition of
detection
At power-on, an IPC communication error has occurred 10 times or more
between the reader unit and DADF/editor within a specific period of time
(1.5 sec).
E712
Main cause The DADF/editor has an IPC communication error.
Condition of
detection
The IPC communication with the reader unit is interrupted for a specific pe-
riod of time (5 sec) or more.
ERROR CODE
E-15