3
Features and Functions
180
Keysight 34980A Mainframe User’s Guide
You can configure the behavior of the alarm output lines as described below. The
behavior of the alarm annunciators on the front panel also tracks the alarm output
configuration. The configuration that you select is used for all four alarm output
lines. A Factory Reset (
*RST
command) clears all four alarm outputs but does not
clear the alarm queue in either configuration.
–
Latch Mode
: In this mode, the corresponding output line is latched true when
the first alarm occurs and remains asserted until you clear it by initiating a new
scan or cycling power. You can manually clear the output lines at any time
(even during a scan) and the alarm data in memory is
not
cleared (however,
data is cleared when you initiate a new scan).
–
Track Mode
: In this mode, the corresponding output line is asserted only when
a reading crosses a limit and remains outside the limit. When a reading returns
to within limits, the output line is automatically cleared. You can manually
clear the output lines at any time (even during a scan) and the alarm data in
memory is
not
cleared (however, data is cleared when you initiate a new scan).
The alarm outputs are also cleared when you initiate a new scan.
– You can control the slope of the pulse from the alarm outputs (the selected
configuration is used for all four outputs). In the falling edge mode, 0V (TTL
low) indicates an alarm. In the rising edge mode, +5V (TTL high) indicates an
alarm. A Factory Reset (
*RST
command) will reset the slope to falling edge.
Note
:
Changing the slope of the output lines may cause the lines to change
state.
Front Panel Operation:
– To manually clear all four alarm output lines, select:
Alarm > CLEAR ALARM OUT? > YES|NO
– To select the output configuration for all four output lines, select:
Alarm > ALARM OUT SIGNAL > TRACK|LATCH
– To configure the slope of all four output lines, select:
Alarm > ALARM OUT SLOPE > NEGATIVE|POSITIVE