DH Instruments COMPASS FOR MOLBOX, User Manual

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COMPASS

for molbox™ User’s Manual
Page 117
© 1998-2003 DH Instruments, Inc .
Table 40. Hardware Definition , <Edit Controller> Screen Fields
FEATURE FIELD TYPE DESCRIPTION
K Factor to N2 Optional Numeric
Entry This is the flow controller’s gas conversion factor from the selected
<Calibration Gas> to N2. A new value can be entered for every
<Calibration Gas> gas selected. The values entered are used to
improve the control accuracy when the flow controller is used
during
[Run DUT] and [Run Test] run modes.
Remote Interface Drop Down
Selection
The choices available are <RS232> , <IEEE-488> and <Voltage/Current> .
To set up the flow controller for remote communications, select the
appropriate interface. When an interface type is selected, the rest of the
<Remote Interface> and command information panels change as
appropriate to accommodate definition of the interface characteristics.
<RS232> and <IEEE-488> selections require set command
information. Use <Voltage/Current> when the flow controller
requires an analog power supply to set the flow. If this is the
selection, V, mV, A or mA must be the flow controller
<Set Units> .
RS-232 Settings Conditional Display
Panel
If the remote interface selection is RS-232, the <RS232 Settings>
information is shown. When creating a new flow controller
Definition, the settings are loaded with
COMPASS default settings.
Port settings are listed baud rate, parity, data bits, stop bits.
Clicking on any setting field causes the <RS232 Settings> Editor to
appear. Select the correct settings for the device from the drop
down list and click
<OK> (see Section 13.3.1).
IEEE-488
Address
Conditional Entry
Field If the remote interface selection is IEEE-488, the <IEEE-488
Address> entry field is shown. When creating a new reference
device, the IEEE-488 address is set to the default address, 10. The
address can be edited directly in the entry field.
Initialization
Commands
Action Button Click this button to display the <Remote Command Editor> form (see
Section 13.6). Enter the desired commands then close the form. These
commands are issued during the initialization process if required by the selected
flow controller. Each device may or may not require a specific initialization.
Refer to the device’s remote interface manual to determine the necessity
of initialization commands. Some devices may require a unit, range and/or
gas selection before being used. If this is the case, and the device has the
necessary commands to complete the task, enter the commands in the
remote command Editor. The response of these commands is not used
by
COMPASS .
Set Commands Action Button Click this button to display the <Remote Command Editor> form (see
Section 13.2.3). Enter the desired set commands then close the form.
Set commands typically require the
<Set Unit Variable> to specify
where the numerical target flow information should be located in the
command string. Enter the command string then
drag and drop or type
the <Set Unit Variable> text into the appropriate location in the
command string. COMPASS substitutes the current numerical set point
in the <Set Units> with the <Set Unit Variable> to create the final set
command. This command is sent as needed to control the flow. Up to
10 commands can be issued as part of the target flow process.
Communications
Test
Action Button This feature can be used only when the <Output Type> is RS-232 or IEEE-488.
Press this button to send the <Initialization Commands> and a single
target flow. When the option is first selected, a dialog box prompts for
the desired target flow. A
<Spy Window> will display with the command
response information used (see Section 6.7.7). This feature is designed
to provide on the spot troubleshooting of the remote command setup. If
a command is not properly entered or the response format is not correct,
the problem should be visible in the spy window. Use the
<Remote
Communications> option for further troubleshooting (see Section 13).