GRAPHTEC gl7000 User Manual page 174

CHAPTER 3 Measure and Set
(12)-4 Level/Upper limit value/Lower limit value
Sets the trigger comparison level.
If the mode is "High" or "Low", it's set to a 1 field comparison level. If the mode is "Win in" or "Win out", its set
to a 2 field comparison level.
Hysteresis
A hysteresis is set up in the trigger levels in order to prevent false positives due to noise. The hysteresis is
as shown on the chart below.
Therefore, even for level sets, errors as shown in the chart below may occur.
<Ex.>
Combination : Edge OR
Mode : High
Level : 0.5 V
•
When the hysteresis is not provided
Trigger (alarm) level
* If the hysteresis is not provided, the rising may be detected even when the rising has been set.
•
When the hysteresis is provided (GL7000)
Trigger (alarm) level
Hysteresis level
* For Rising mode, when the signal level drops below the hysteresis level at a time, and then becomes greater
than or equal to trigger (alarm) level, the tigger (alarm) is detected.
Hysteresis level
Each Hysteresis level is as shown below.
•
<Mode: Rising>
Trigger (alarm) level
Hysteresis level
•
The upper limit values within the mode range and the lower limit values out of the mode range are hysteresis level as well.
•
An error of the trigger (alarm) level is the same as the voltage accuracy and temperature accuracy.
•
When the detected alarm drops below the hysteresis level, it is cleared. (When the alarm is retained).
•
For Pulse mode, the Hysteresis level is not provided.
3-108
The trigger (alarm) is detected here.
The trigger (alarm) is detected here.
Trigger (alarm) point
0.5000 V
0.5000 V
0.4900 V
0.5000 V
Hysteresis level
<Voltage>
• 1% of the level set value range
(1 V range: level set value -0.01 V)
<Temperature>
• Level set value -0.5ºC