Epson RC520 Manual page 22

Setup & Operation 1. Safety
Irregular Motor Torque (out-of-control manipulator) Detection:
The dynamic brake circuit is activated when irregularity with motor torque (motor output)
is detected (in which case the Manipulator is out of control).
Motor Speed Error Detection:
The dynamic brake circuit is activated when the system detects that the motor is running
at incorrect speed.
Positioning Overflow - Servo Error - Detection:
The dynamic brake circuit is activated when the system detects that the difference
between the Manipulator's actual position and commanded position exceeds the margin
of error allowed.
Speed Overflow - Servo Error - Detection:
The dynamic brake circuit is activated when the system detects that motor speed has
overflowed.
CPU Irregularity Detection:
Irregularity in the motor controlling CPU is monitored by a watch-dog timer. Also, the
system CPU inside the Control Unit and the motor controlling CPU inside the Drive Unit
are designed to constantly check each other for any discrepancies between the units. If a
discrepancy is detected, the dynamic brake circuit is activated.
Memory Check-sum Error Detection:
The dynamic brake circuit is activated when a memory check-sum error is detected.
Overheat Detection at the Motor Driver Module:
The dynamic brake circuit is activated when the temperature of the power device inside
the Motor Driver module is above the nominal limit.
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RC520 Rev.7