Omron K6CM User Manual page 53

Trigger example with moving average (moving average times = 2)
During
startup
Motor
of the
Before
motor
operation
Rotation
of the
speed
motor
Measured
value
Measured
value after
moving average
Trigger timing
Measurement and monitoring are not possible.
Sampling period
If the trigger condition is
satisfied during calculation of
"Measured value 4", the
measured value is updated with
"Measured value 2 and 3" which
have been calculated during startup
of the motor.
As shown above, if the moving average times = 2, stable measured value can be measured when trig-
ger is started after the sampling period × (moving average times + 1) = sampling period × 3 or more has
elapsed after the motor entered stable operation.
Also, in accordance with the purpose and operating state of the motor, determine the measurement
time as the number of seconds for which measurement is to be performed after trigger start (when the
trigger type is Rising edge or Falling edge).
Stable measured values can be measured by making the settings so that the measurement time fits
within the motor stable operation. Consider the timing of trigger release and determine the measure-
ment time.
The sampling period differs for each measurement target. When you determine the trigger start timing,
consider which sampling period of measurement target should be used according to the purpose.
Example) When the moving average times = 2 for the vibration & temperature type
Sampling period of acceleration: 50 ms
Sampling period of velocity: 0.5 s
Sampling period of temperature: 0.5 s
When you want to measure acceleration, velocity, and temperature at the same time, calculate the
trigger start timing as follows using the sampling period 0.5 s of the speed and temperature which is
the longest sampling period.
Sampling period × (moving average times + 1) = 0.5 s × (2 + 1) = 1.5 s.
If you want to measure only the acceleration, you can calculate the trigger start timing with sampling
period 50 ms.
Note When the time during which the motor is performing stable running is short, you may not be able to release
the trigger during stable motor operation if the measurement time is lengthened. Measure with long opera-
tion time of the motor in accordance with the actual usage, or shorten the measurement time.
K6CM Motor Condition Monitoring Device User's Manual (N219)
During stable motor operation
Sampling period × 3
Measurement and monitoring are possible.
Measured Measured Measured Measured
value 1 value 2 value 3 value 4
Trigger start
If the trigger condition is satisfied after calculating "Measured value 4", the
measured value can be updated with "Measured value 3 and 4" which is
calculated during stable operation of the motor.
If the trigger condition is satisfied after sampling period × 3, the measured
value is a value secured after calculation of "Measured value 4".
3 Measuring and Monitoring Mechanism
Sampling period × 3
Measuring time
Trigger release
Changing
motor
rotation
During stable
speed
motor operation
Can
Cannot measure
measure
and
and monitor
monitor
Trigger start
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