YOKOGAWA UTAdvanced UT55A, User Manual

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10-9
IM 05P01C31-01EN
Output
(Control
and
Retransmission)
Functions
10.6 Reducing 4-20 mA Current Output to 0 mA
(Tight Shut Function)
Description
Tight shut function fully closes the control valve (or other actuators) (i.e., so that output is
zero) beyond its positioner dead band.
When the output low limit is set to “SD,” the output is as follows in MAN or AUTO mode.
• In MAN mode
When the output is reduced with the Down arrow key and “SD” is displayed as the
output value, the output level reaches tight shut level. The control output delivers a
tight shut signal (about 0.0 mA).
• In AUTO mode
The output is limited by the output low limit (OL). It does not decrease to 0.0 mA.
Control output
20.0 mA
–
5.0%
100.0%
Displayed output value
3.2 mA
4.0 mA
0.0 mA
Setting Details
Parameter
symbol
Name
Display
level
Setting range Menu symbol
OL
Control output low limit
Heating-side control
output low limit (in
Heating/cooling
control)
EASY
-5.0 to 104.9%, (OL<OH), SD:
Tight shut (0 mA output in
MAN mode)
In Heating/cooling control: 0.0
to 104.9% (OL<OH)
PID
PIDN
PID number selection EASY 1 to 8 SP
PIDG. Number of PID groups STD 1 to 8 CTL
Note1: The PID number (1 to 8, R) is displayed on Group display while each parameter is displayed.
Note2: In Cascade control, the LP2 lamp is lit while the Loop-2 parameter is displayed.
Note
When changing the setpoint of the parameter PIDG., if the setpoint of the parameter PIDN
which belongs to the SP menu is larger than that of the parameter PIDG., the PIDN setpoint is
changed to the PIDG. setpoint.
10