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