Canon CXDI-1 Operation Manual page 161

If connecting an unregistered sensor unit
The message "Sensor Unregistered Error" is displayed if a sensor unit having serial
number that has not already been registered is connected. After confirmation, touch
[OK] to close the window and connect a sensor unit having a registered serial number.
4
Complete connecting the sensor unit.
Touch [OK] on the dialog box.
The sensor unit icon display will change.
C. Using the Sensor Unit Attach/Detach Function
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