Yokogawa YVP20S - Manual (Page 98)

9-21
IM 21B04C50-01E
<Toc> <Ind> <9. CONFIGURATION SERVICES>
Compound Lever
The compound linkage has Lever1 attached at one end to the pivot (the position sensor in
the YVP) and at the other end to Link L2. In order to compute the proper correction curve,
the user must enter the stroke length, first lever segment length (L1), second lever segment
length (L2), the distance from the pivot to the valve stem pickup (L3), and the valve position
at horizontal. Most linkages use a linkage with L3 equal to L1, i.e. the second lever arm is
vertical when the first lever arm is horizontal. The correction computation will correctly
compute the correction curve when L3 is not equal to L1. However, L3 must be greater
than 0, which requires that the valve stem pickup not be lined up with the pivot and that the
pickup be on the same side of the pivot as the link between the first and second lever.
Click OK to compute the correction and display the curve. A Dialog will appear to show the
angle the linkage will move.
Figure 9.12 Rotation Angle Message
The (custom) define characterization must be the selected configuration option to use the
generated curve. Click OK to accept the displayed curve.
9.6.2 Pressure Frame
● Pressure Units
This is the unit code in TB_SPRING_RANGE parameter which affects output pressure unit
code as well. However, it has no effect in controlling function.
● Pressure Upper Range (EU100)
This is EU100 of SPRING_RANGE of TB parameter for upper end engineering unit value.
● Pressure Lower Range (EU0)
This is EU0 of SPRING_RANGE of TB parameter for lower end engineering unit value.
● Supply Pressure
This is the supply pressure in engineering units specified in SPRING_RANGE parameter. It
is for information only and has no effect on control.
9.6.3 Others Frame
● Bumpless Transfer
When this option is selected, returning from manual to normal operation state is deferred
until the current valve position and the position setpoint match. This is to assure the smooth
valve position transition when switching the operation state to avoid a process disturbance.
For most Foundation fieldbus installations, the initialization function built into the function
blocks will handle bumpless transfer. Leave the box unchecked unless there is a special
requirement.
● Display Language
It is currently unused.
● Temperature Units
This is the temperature unit used in the device which has choice of either degC or degF.