Azbil AVP200, Руководство пользователя

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4-15
Chapter 4: Communication-Based Operation
4.4.7 Travel Cutoff
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Travel Cutoff
Sets the input signal values (%) that force the valve fully open and fully closed. The
valve will be fully closed at input values less than the forced fully closed value, and will
be fully open at input values greater than the forced fully open value. The input signal
values (%) for the valve forced fully open and fully closed are set independently. An
overview of the input/output characteristics when forced fully closed/open values have
been set is shown below.
Figure 4-5. Forced Fully Open/Closed Settings
Note
•
Set these parameters such that the forced fully open setting (Travel Cutoff High) is
greater than the forced fully closed setting (Travel Cutoff Low).
•
If a span adjustment is performed after auto-setup has been executed, the forced
fully open setting will be 1 % less than the overstroke percentage.
•
The forced fully open and forced fully closed settings have a hysteresis difference of
0.1 %
•
As a result of configuring the forced fully closed setting, the control valve can be-
come fully closed when the input signal drops to the preset value or lower, so set
the output limiter (Lo) on the host to −1 % or higher.
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Travel Cutoff Low configuration procedure
Step Procedure
1 Select [Device] >> [Setup] >> [Travel Cutoff] >> [Travel Cutoff Low].
2 Specify the input signal value at which to force the valve fully closed.
3 Send the modified setting to the device using the transmission button.
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Travel Cutoff High configuration procedure
Step Procedure
1 Select [Device] >> [Setup] >> [Travel Cutoff] >> [Travel Cutoff High].
2 Specify the input signal value at which to force the valve fully open.
3 Send the modified setting to the device using the transmission button.