YOKOGAWA UP35A, User Manual

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10-15
IM 05P02D41-01EN
Output (Control and Retransmission) Functions
10.10 Setting Hysteresis and Dead Band for Position
Proportional Control Output
Description
To prevent excessively frequent operation of the motor and relays, a dead band is
provided between two relay output operating points, and hysteresis is provided for each
relay output.
If position signal differs from the control computation output by less than the dead band
value, neither the “direct” nor “reverse” relay turns ON. If the difference is large enough
on the plus side, the direct relay turns ON; if on the minus side, the reverse relay turns
ON (in reverse action).
Reverse
output (ON)
Direct output (ON)
Neutral (OFF)
Dead band
0
(Control computation output value
–
Position signal)
Position proportional
output relay hysteresis
Position proportional
output relay hysteresis
Setting Details
Parameter
symbol
Name
Display
level
Setting range Menu symbol
HYS
Hysteresis (in ON/OFF
control, or Position
proportional control)
Heating-side ON/OFF
control hysteresis
(in Heating/cooling
control)
EASY
In ON/OFF control: 0.0 to
100.0% of PV input range
span (EUS)
In Heating/cooling control
or Position proportional
control: 0.0 to 100.0%
PID
DB
Output dead band (in
Heating/cooling control
or Position proportional
control)
EASY
In Heating/cooling control:
-100.0 to 50.0%
In Position proportional
control: 1.0 to 10.0%
Note1: The PID number (1 to 4, R) is displayed on Group display while each parameter is displayed.
10