HP 34970A Alarm System Overview Alarm Output Commands, OUTPut ALARmMODE LATChTRACk ALARmMODE?

Chapter 5 Remote Interface Reference

Alarm System Overview

Alarm Output Commands

Four TTL alarm outputs are available on the rear-panel Nv 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 any of the associated channels will pulse the line).

OUTPut

:ALARm:MODE {LATChTRACk}

: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 line is automatically cleared. The :MODE? query returns the alarm output configuration. Returns “LATC” or “TRAC”.

OUTPut

:ALARm:SLOPe {NEGativePOSitive}

: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”. b vv”” z z

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OUTPut :ALARm{1234}: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 lines at any

time (even during a scan) and the alarm data in memory cleared (however, data is cleared when you initiate a new scan). The alarm outputs are also cleared when you initiate a new scan.

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