Chapter 5 Remote Interface Reference

Alarm System Overview

∙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.

You can also initiate a scan sweep (no external wiring required) when an alarm event is logged on a channel. For complete details, refer to “Using the Alarm Output Lines” on page 128.

∙In addition to being stored in reading memory, alarms are also recorded in their own SCPI status system. You can configure the instrument to use the status system to generate a Service Request (SRQ) when alarms are generated. See “The SCPI Status System,” starting on page 275 for more information.

∙The default values for the upper and lower alarm limits are “0”. The lower limit must always be less than or equal to the upper limit, even if you are using only one of the limits.

To ensure that an error is not generated when using only an upper or lower limit, execute the following command sequence (this example assumes that you are setting only a lower limit):

CALC:LIMIT:UPPER MAX,(@101);LOWER 9,(@101);LOWER:STATE ON

 

∙ A Factory Reset (*RST command) clears all alarm limits and turns off

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all alarms. An Instrument Preset (SYSTem:PRESet command) or Card Reset (SYSTem:CPON command) does not clear the alarm limits and does not turn off alarms.

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