Specifications

Guide to Operation
21
GUIDE TO OPERATION
FRONT PANEL SUMMARY
POWER BUTTON
The SR400 is turned on by depressing the
POWER button. All instrument settings are stored
in nonvolatile memory and are retained when the
power is turned off. The model, firmware version,
and serial numbers of the unit will be displayed
briefly when the power is turned on. The recall
status is also dipslayed. If recall is OK, then the
instrument returned to the settings in effect when
the power was last turned off. If recall is ERR,
then the stored settings were lost and the default
settings are used. If recall is DEFAULT, then the
instrument is resetting to default conditions. This
is done if the STOP (RESET) key is held down
when the power is turned on. The default setup is
listed in the next chapter.
LIQUID CRYSTAL DISPLAY
The 2 line by 24 character LCD is the user
interface for data display and front panel
programming operations. The top line always
shows count data. The lower line is the menu line
and displays one line of setup information. The
LCD is backlit by an electroluminescent panel for
convenient operation in low light level conditions.
When in the SETUP menu, the contrast of the
LCD may be adjusted for optimum viewing.
MENU KEYS
All operating parameters of the SR400 are
grouped into six function menus. The six menu
keys select the group of functions to be
programmed. The four arrow keys select
individual parameters within each menu. The
selected parameter is displayed on the menu line
of the display.
The MODE menu selects the counting mode,
counter inputs, counter presets, scan mode and
length, dwell time, analog output, and display
mode. The LEVEL menu adjusts the
discriminator, trigger, and D/A levels. The A
GATE and B GATE menus program the gate
generators. The SETUP menu provides STORE
and RECALL of 9 different instrument setups and
adjustment of the LCD contrast. The COM menu
sets up the computer interface parameters and
displays received data. Detailed descriptions of the
menus are provided at the end of this section.
SPIN KNOB
All parameters are altered using the spin knob.
Whenever the menu line has an active or flashing
cursor, the displayed parameter can be adjusted
with the knob.
START, STOP, AND RESET
The two count keys, START and STOP, are used
to start, pause, and reset the counters.
A scan can be started only if the counters are in
the reset condition; all scanned parameters are at
their start values and the counters are reset to zero.