Omron C200H-MC221 Operation Manual page 41

Failsafe Circuits
Example 1
PC
Ladder
programming
Example 2
Error Counter Alarm
PC
bit is turned ON.
Ladder
programming
External
output
External Emergency Stop Circuit
Error Counter Alarm
bit is turned ON.
External Immediate
output stop input
In the Example 2, when the Error Counter Alarm Bit is turned ON, the dynamic
brake of the motor is actuated by an external output from the PC to stop the mo-
tor.
MC Unit
Amp
Error
counter
In either of the above examples, the motor makes a sudden stop when the error
counter overflows. Make sure that this sudden stop will not result in damage to
the system.
In addition to the failsafe circuits shown above, a failsafe circuit is normally set up
using monitoring sensors installed at the edges of the workpiece's range of
movement to detect abnormal workpiece movement and stop operation if a run-
away occurs.
Monitoring sensor Limit input
Monitoring sensors are installed outside of the limit inputs. If the workpiece
reaches one of the sensors, the power is turned off to the servodriver and then
the dynamic brake is applied to stop the motor.
MC Unit
Speed
control
voltage
Error
counter
Operation
command
output
Voltage
output
Servo
driver
Normal operating range
Maximum range of movement
Section 3-4
Servodriver
Servomotor
Limit input Monitoring sensor
27