E280: Unexpected activation of zero position sensor on CEPH /
E281: Timeout of zero position sensor on CEPH /
E282: Zero position sensor for CEPH never active /
E283: Zero position sensor for CEPH always active

All the messages refer to the optical barrier that is sensing the zero
position of the Digital Ceph sensor holder; differences between their
meanings are that the first one (E280) may occur during the
examination, meaning that the senor activation has occurred before the
expected time. This can be caused by the loss of motion of the stepper
motor due to a collision with the patient or a fault of the motor stepper
driver. In case that no collision has been observed or the message is frequently

displayed, follow the procedure.

The last 3 messages are displayed during the power on phase, when the
system is controlling the functionality of the whole system.
E281 and E282 mean that the zero position sensor is never activated;
due to a motor not running or to a fault of the optical barrier (the sensor
or its harness); E283 means that this sensor is always activated. Also in
this case the fault can be the motor or the optical barrier.

•      Check that during the power on phase there are movements on these
       axes; the normal motion is going to engage the sensor and a reverse
       motion to disengage it. If no motion is observed, the fault can be the
       stepper motor or the cable connecting it to the main CPU. Check that
       the cables between the motor M8 and X6 of board A12 is well
       inserted, as for the cable X1-X2 of A12 to X23, X24 and X34 of the
       main CPU A5
•     Check continuity of the above cables, from M8 to board A12 and from
       X1-2 of board A12 up to X23, X24 and X34 of the main CPU (A5)
•     Repeat the power on sequence, verifying the motion.
If still there is no motion, replace the stepper motor and, if not fixed,
replace the CPU.

If a motion has been observed, but messages are displayed, this can be
the sensor or its wiring:

•        Power off the system and try to manually disengage the sensor,
          taking care of a smooth motion.
•         Power on the system and check the functioning of the sensor,
          measuring the DC voltage on the terminal of the sensor B10, with
          and without an obstacle manually inserted. A variation of about
          3.5 V minimum should be observed. If not, replace the sensor.
•        If the variation is observed and the message still continues to be
         displayed, check the correct insertion of cable X5 on A12 board and
         from X1-2 of the board up to X23, X24 and X34 of the main CPU;
         check the continuity of the interested wires and replace the faulty
         one (if any).
•        If all cables are OK, the fault is on the CPU, so replace it.