KEYENCE EX-V Series User Manual
Page 88
Chapter 4 Use of Data Processing Functions
4
78
Bottom hold function [b-2]
Measures the "minimum value" during a specified period (sampling period).
For the bottom hold function, the sampling period can be specified with the
combination of the trigger mode and delay time settings.
➮ For the details of the trigger mode and delay time, refer to pages 69 and 70.
➮ For the details of flicker delay, refer to pages 70 to 73.
Timing diagram
■ External trigger mode
•
The sampling period is between the UP edge of the timing input (hold-reset
input) and the UP edge of the next timing input.
•
The value measured at the instant when the timing input turns ON is displayed/
output.
Reference: To clear the measured value being held and to start the measurement
again, short-circuit the hold-reset and GND terminals.
■ Internal trigger mode (Example of internal trigger DOWN )
•
The sampling operation starts when the sampling delay time elapses after the
measured value falls below the trigger level. When the sampling period elapses,
the internal timing signal is turned ON and the bottom value is displayed/output.
•
For the internal trigger up operation, the trigger point is the instant when the
measured value exceeds the trigger level.
•
The instant when the sampling starts, the strobe output turns ON.
•
Turning the strobe output from ON to OFF results in the off-delay of 2 ms for
updating the comparator output.
Reference: To clear the measured value being held and to start the measurement
again, short-circuit the hold-reset and GND terminals.
(t)
0
ON
OFF
When the power is turned ON or the hold-reset signal is input,
the display shows " " until the first timing signal is input.
Displayed value
Timing input
Sampling period
Sampling period
Sampling
period
(t)
0
ON
OFF
ON
OFF
ON
OFF
When the power is turned ON or the hold-reset signal
is input, the display shows " " until the first
measured value is determined.
Displayed value
Internal data reset
Internal timing
Strobe output
Trigger
point
Bottom hold value
Sampling delay
Sampling period
Sampling delay
Sampling period
Trigger level