Instrutech Hornet User Manual page 26

Instruction Manual
The program code control logic is such that when switching from DIGI controls to RS485 controls,
the device will invoke a 'safe state' if any RS485 command is sent to switch from DIGI to RS485. A
command sent to the IGM401 such as IG ON/OFF, DEGAS ON/OFF or SET ION GAUGE EMISSION
CURRENT will cause the IGM401 to automatically switch from the DIGI mode to the RS485 control
mode. Sending READ commands such as read gauge pressure will not accomplish this task. When
operating in the RS485 mode, all other inputs are ignored (i.e., the host has control).
Note - To change from the RS485 to another IG CNTL mode, the reset command must be sent to the IGM401 or
power must be turned off and on. This will reset IG CNTL to the DIGl/RS485 factory default setting with the
default state of this selection being the Digital Input (DIGI) again.
 FRONT PANEL
This mode of operation allows the user to manually turn the IG filament on/off, select emission
current and turn degas on/off using the front panel soft-keys. This is achieved by selecting FRONT
PANEL in the IG CNTL submenu of the SETUP UNIT menu. In this case the FRONT PANEL overrides
any other input and the DIGI/RS485 inputs are ignored. If FRONT PANEL is selected, the following
Top-Level Program Menu will be displayed after the MENU key is pressed. Compare the following
program selection menu to the selection choices shown at
parameters and settings.
- Top-Level Program Menu when FRONT PANEL is selected for IG CNTL:
(A)
IG ON/OFF [Factory default = OFF] If the IG is in the default OFF state, select the IG ON line in the
displayed menu and then press ENTER to turn the IG ON. The device will respond immediately to either
entry of IG ON or IG OFF when selected and ENTER is pressed.
(B)
EMISSION SEL [Factory default =100UA] Access setting to change emission current to 4 mA or 100 µA.
(C)
DEGAS ON/OFF [Factory default = OFF] Access setting to turn degas on or off. Degas operation may be
invoked immediately when the IG filament is in the ON state by pressing the ENTER key after selecting
DEGAS ON in the main TOP-LEVEL Program Menu. The device will respond immediately after the ENTER
key is pressed for either DEGAS ON or DEGAS OFF.
InstruTech, Inc.
(A)
IG ON
(A)
IG OFF
SETUP DISP
SETUP UNIT
SETUP IG
SETUP COMMS
SERVICE MENU
(B)
EMISSION SEL
(C)
DEGAS OFF
(C)
DEGAS ON
IGM401 Hornet
section 5.7 for default program
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