Справочник Пользователя для National Instruments FP-3000
Chapter 3
Example Applications
3-12
©
National Instruments Corporation
In the case of Analog Output blocks, you do not need to tell the block to use
the scaling parameters. The block will always use both
the scaling parameters. The block will always use both
XD_SCALE
and
PV_SCALE
parameters.
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, complete the
following 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, complete the
following 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.
Bring the Block Online
1.
Go to the
MODE_BLK
parameter and set the
TARGET
to
Auto
.
2.
Re-read the
MODE_BLK
parameter. The
ACTUAL
field should go to
Auto
. If it does not, refer to Appendix C,
, for
more information.
Once the block goes to
Auto
, it is fully operational. You can adjust the Set
Point by writing a value between 0 and 100 to SP. The current flow through
the heating element will vary.
the heating element will vary.
If you are only interested in making FP-3000 output current and not
interested in closed loop control, you are finished with this example.
interested in closed loop control, you are finished with this example.