Yokogawa digitalYEWFLO (DY-FF) - Manual (Page 75)

<APPENDIX 2. APPLICATION, SETTING AND CHANGE OF BASIC PARAMETERS>
A2-1
IM 01F06F00-01EN
APPENDIX 2. APPLICATION, SETTING
AND CHANGE OF BASIC
PARAMETERS
A2.1 Applications and Selection of Basic Parameters
Setting Item (applicable parameters) Summary
Tag numbers (PD-TAG) Set the physical device (PD) tag and block tags. Up to 32 alphanumeric characters can be set for
each of these tags. Refer to Section 5.4 “Setting of Tags and Addresses.”
Calibration range setup
(XD_SCALE of AI block) Sets the range of input from the transducer block corresponding to the 0% and 100%
points in operation within the AI1 function block. The maximum fl ow rate range in the registered
sizing data is the factory default setting.
Set four data: the unit of the range, the input value at the 0% point (always 0 for a
digitalYEWFLO), the input value at the 100% point (equal to the fl ow span), and the decimal
point position.
Output scale setup
(OUT_SCALE of AI block) Set the scale of output corresponding to the 0% and 100% points in operation within the
AI function block. It is possible to set a unit and scale that differ from the measurement range.
Set four data: the unit of the scale, the output value at the 0% point (i.e., the lower output scale
limit), the output value at the 100% point (i.e., the upper output scale limit), and the decimal point
position.
Output mode setup
(L_TYPE of AI block) Select the calculation function of each AI function block from the following:
• Direct:
The output of the transducer block is directly output only via fi ltering without
scaling and square root extraction (in the range set in XD_SCALE).
• Indirect: Proportional scaling is applied to the input to the AI function block, and the
result is output (in the range set in OUT_SCALE).
• IndirectSQRT: Square root extraction is applied to the input to the AI function block and the
result is output (in the range set in OUT_SCALE). This setting is not used for a
digitalYEWFLO.
This output mode setting also applies to the scale and unit of indications on the LCD indicator.
Damping time constant setup
(PRIMARY_VALUE_FTIME of
TR block) Set the time constant of damping in seconds. The setting of PRIMARY_VALUE_FTIME affects
not only the fl ow rate but also the totalization. In comparison, the setting of parameter PV_FTIME
in an AI function block works as the damping time constant for the AI block’s OUT. As the
damping feature of the fl owmeter itself, it is advisable to use PRIMARY_VALUE_FTIME.
Output signal low cut mode setup
(LOW_CUT_FLOW of TR block) This setup is used for zeroing fl ow rate readings in a low fl ow rate area. The value of LOW_
CUT_FLOW (the cutoff level) is set in the same unit as that for PRIMARY_VALUE_RANGE. In
comparison, the setting of parameter LOW_CUT in an AI function block works as a low cutoff
level setting for the AI block’s OUT. As the low cutoff feature of the fl owmeter itself, it is advisable
to use LOW_CUT_FLOW.
Simulation setup
(SIMULATE of AI/DI block) Simulation of each AI/DI block can be performed in such a way that the value and status of the
input to the block can be set arbitrarily. Use this function for loop checks or the like. Refer to
Section 7.3 “Simulation Function. ”
LOD display setup
(UPPER_DISPLAY_MODE,
LOWER_DISPLAY_MODE, and
DISPLAY_CYCLE of TR block) Set the units of data to be displayed on the LCD, and the display refresh cycle. Adjust DISPLAY_
CYCLE to improve legibility such as when used in a low temperature environment causing
hard-to-read indications.
Calibration range change
(CAL_POINT_HI and
CAL_POINT_LO of TR block) Set the 0% and 100% points for calibrations, i.e., the calibration range. The output can be
calibrated precisely to the output of a user’s reference device.