Alarm Output Commands
Four TTL alarm outputs are available on the rear-panel Alarms
connector. You can use these hardware outputs to trigger external
alarm lights, sirens, or send a TTL pulse to your control system.
Each alarm output line represents the logical “OR” of all channels
assigned to that alarm number (an alarm on a ny of the associ ated
channels will pulse the line).
OUTPut
:ALARm:MODE {LATCh|TRACk}
:ALARm:MODE?
Select the configuration of the four alarm output lines (the configuration
applies to all four alarm output lines). In the “LATCh” mode (default),
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. In the “TRACk” 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 li ne i s a u tomat ica ll y
cleared. The :MODE? query returns the alarm output configuration.
Returns “LATC” or “TRAC”.
OUTPut
:ALARm:SLOPe {NEGative|POSitive}
:ALARm:SLOPe?
Select the slope of the pulse from the alarm outputs (the selected
configuration is used for all four outputs). If you select NEG (default),
0V (TTL low) indicates an alarm. If you select POS, +5V (TTL high)
indicates an alarm. The :POL? query returns the alarm output
configuration. Returns “NEG” or “POS”. Note that changing the slope of
the output lines may cause the lines to change state.
OUTPut
:ALARm{1|2|3|4}:CLEar
:ALARm:CLEar:ALL
Clear the specified alarm output lines. Send :CLEAR:ALL to clear all
four alarm output lines. You can manually clear the output lin es 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.
Chapter 5 Remote Interface Reference
Alarm System Overview
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