American Magnetics 185 & 186 Liquid Level Instruments (CE-Marked) - Manual (Page 67)

Rev. 3 57
Virtual Instrument Operation
IEEE-488 Virtual Instrument
primary address (see page 44 for instructions on setting the Model 185/186
primary address). If only one GPIB interface is present in the host
computer, the GPIB bus is normally set to 0. Refer to your LabVIEW
documentation for more information on how to determine the GPIB bus
setting appropriate for your computer. After setting the initialization
parameters, the user may then start the VI. Please refer to your LabVIEW
documentation for instructions on how to start and control the execution of
VI’s.
6.2.2 Interacting with the running VI
While the VI is running the user may manipulate the virtual toggle and
rotary switches in the same manner as required for the front panel
operation of the actual instrument. See the Operation section of this
manual for instructions on operating the front panel controls, however,
please note that there are some minor differences discussed below.
The RAISE/LOWER toggle switch functions slightly different in the VI. If
the RAISE/LOWER toggle switch is moved from the center position to the
RAISE or LOWER position, then the display changes to show the
appropriate parameter. After approximately 4 seconds in the RAISE or
LOWER position, the display will begin incrementing or decrementing by
tenths. After approximately 12 additional seconds, the display will begin
incrementing/decrementing by ones. Move the RAISE/LOWER toggle
switch back to the center position to stop the incrementing or
decrementing function.
The virtual instrument’s FILL LED indicator is only accurate if the fill
toggle switch is in the AUTO position. There is no remote monitoring or
control of the manual override states of the fill toggle switch available
through the communication command set.
As a more convenient option for controlling the settings, the user may
scroll to the area above the VI and enter the values for the Sensor Length,
Hi Setpoint, A Setpoint, B Setpoint, Lo Setpoint, and Fill Interval directly
in the control fields (please observe the specified units). Any changes in
the fields are recognized and sent to the actual instrument in the form of
the appropriate command string. Any settings changed by the VI virtual
panel toggle switches or control fields are saved in permanent memory in
the actual instrument. The control fields and toggle switches function
whether the VI is run exclusively or non-exclusively on the GPIB bus.
If the VI is executed exclusively, then the VI may be gracefully stopped by
using the STOP toggle switch in the lower left corner of the VI. After
stopping the VI, this switch must be placed back in the up position in order
to restart the VI. If you are executing the VI in a non-exclusive polling loop
on the GPIB bus, then the STOP toggle switch has no function and the
user should control the execution of the VI from the controlling parent
VI(s).