•   SET ALARMS...       W      Opens a window (shown in the following example) that allows you to set up the alarm status for each channel.  An alarm is triggered whenever the input to that channel violates certain conditions -- some fixed, some user-specified.  If alarms are set, warnings of alarm conditions appear in the upper right corner of chart output during data gathering.  Optionally, an audible buzzer can be triggered by an alarm condition.  Finally, a summary of alarms can be called up from the Options window at the end of a data run.  Note that alarms do not function with oscilloscope channels.

    Three types of alarms are possible:

    • Overrange (over-voltage) alarms are triggered when the input voltage exceeds the capacity of the A-D converter in use (plus or minus 5 volts with the Sable UI2; plus or minus 0.42 volts with the ADC-1, or plus or minus 3.5 volts with current DataTakers, etc.).  Optionally, the computer will sound an audible alarm when it encounters an overrange condition (note that this will slow acquisition when sampling at high rates). 
    • Upper limit alarms occur whenever the units (after conversion, NOT input volts) exceed a user-set limit. 
    • Lower limit alarms occur whenever the units (after conversion, NOT input volts) fall below a user-set limit. 

    Note that using alarms can slow the maximum possible sampling rate.  However, for most sampling rates, use of alarms has no effect on performance

    go to: