Справочник Пользователя для National Instruments FP-3000
Chapter 3
Example Applications
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National Instruments Corporation
3-9
You can avoid setting the
XD_SCALE
value manually if you set the
CFG_OPTS
option called Automatically adjust XD_SCALE. This
allows the FP-3000 to copy the value from
FP_TC_120_RANGE
straight into the
XD_SCALE
parameter.
2.
Determine the output scale. If you want to output the temperature in
degrees Kelvin, you can set
degrees Kelvin, you can set
OUT_SCALE
to the same values as
XD_SCALE
above. If you want to change to Celsius, you can do so by
setting
OUT_SCALE
as follows:
OUT_SCALE
EU at 100%
1775.00
EU at 0%
-273.15
Units Index °C
Decimal
2
3.
Tell the block to use the scaling parameters. The block is flexible
enough to either ignore scaling (
enough to either ignore scaling (
Direct
), use linear scaling
(
Indirect
), or use square root scaling (
Indirect square root
).
Since you want the block to use linear scaling, set the
L_TYPE
parameter of the block to
Indirect
.
Set Up Scheduling
Before the block will operate, you need to schedule the block to execute.
All Fieldbus function blocks (including function blocks on the FP-3000)
execute according to a schedule. You can specify the order of function
blocks in the schedule and the rate at which the schedule is repeated. To
make the configurator create a schedule for your block, follow these steps:
All Fieldbus function blocks (including function blocks on the FP-3000)
execute according to a schedule. You can specify the order of function
blocks in the schedule and the rate at which the schedule is repeated. To
make the configurator create a schedule for your block, follow these steps:
1.
Double-click on Function Block Application in the tree view of the
configurator.
configurator.
2.
Drag the block from the tree view to the application view. The
configurator automatically generates a schedule for the block that
causes it to run every second (refer to the documentation that came
with your configurator for information about changing the execution
period).
configurator automatically generates a schedule for the block that
causes it to run every second (refer to the documentation that came
with your configurator for information about changing the execution
period).
3.
To download this schedule to the device, select Configure»Download
Configuration. A dialog box appears that enables the configuration to
be downloaded. Go through the download process, as described in the
documentation that came with your configurator. Since the block is not
scheduled when you start the download, its actual mode does not
change until the download is complete.
Configuration. A dialog box appears that enables the configuration to
be downloaded. Go through the download process, as described in the
documentation that came with your configurator. Since the block is not
scheduled when you start the download, its actual mode does not
change until the download is complete.