Yokogawa digitalYEWFLO (DY-FF) - Manual (Page 78)

<APPENDIX 2. APPLICATION, SETTING AND CHANGE OF BASIC PARAMETERS>
A2-4
IM 01F06F00-01EN
A2.4 Setting the Transducer Block
To access the digitalYEWFLO-specifi c functions in
the transducer block, the Device Description (DD)
for the digitalYEWFLO needs to have been installed
in the confi guration tool used. For installation, refer
to Section 4.4 “Integration of DD.”
(1) Setting the damping time constant
FA0208.ai
Access the PRIMARY_VALUE_FTIME
parameter.
Set the damping time constant (in units of
seconds).
(2) Setting the output low cutoff level
FA0209.ai
Access the OUTPUT_CUT_FLOW parameter.
Set the cutoff level of the flow rate output.
Low cut value
Flow rate
Hysteresis 20%
(3) Setting the limit switch functions
Set up limit switches 1 and 2. Limit switch statuses
can be read from a host as outputs of DI blocks.
FA0210.ai
Access the LIMSW_1_SETPOINT parameter
and set the threshold for turning on limit switch
1. As necessary, the on/off hysteresis can be
modified by changing the value of the
LIMSW_1_HYSTERESIS parameter (only a
positive value can be set).
Access the LIMSW_1_ACT_DIRECTION
parameter and select the direction of limit
switch 1’s actions.
1: HI LIMIT High limit switch
2: LO LIMIT Low limit switch
Access the LIMSW_1_TARGET parameter and
select the flow rate or temperature to be
monitored by limit switch 1.
1: PRIMARY_VALUE Flow rate
2: SECONDARY_VALUE Temperature
The above shows the setting procedure for limit
switch 1. As necessary, also set up limit switch 2.
(4) Setting up the LCD display
Select the data to be displayed on the LCD indicator
and the display refresh cycle.
FA0211.ai
First, select the data to be displayed on the
upper row of the LCD. Access the
UPPER_DISPLAY_MODE parameter and
select an item.
1: Flow Rate (%) Instantaneous flow rate
as a percentage
2: Flow Rate Instantaneous flow rate
in the specified unit
3: Temperature(%) Temperature as a
percentage (needs the
option /MV which adds a
built-in temperature
sensor).
4: Arithmetic Out
Access the LOWER_DISPLAY_MODE
parameter and select the data to be displayed
on the lower row of the LCD.
1: Blank
2: Total
Totalized flow rate
3: Temperature Temperature as a
percentage (needs the
option /MV which adds a
built-in temperature sensor).
4: Integrator Out
Access the DISPLAY_CYCLE parameter and
set the display refresh cycle. The cycle can be
set to a multiple of 500 milliseconds in a range
from 1 to 10 (= 500 ms to 5 s), and is set to 1
(= 500 ms) by default. Prolong the cycle as
necessary to improve legibility such as when
used in a low temperature environment which
makes the indications hard to read.