Alarms

Introduction

This section is a description of the Alarms system settings.

Alarms and Warnings

The Alarms settings define the upper and lower Alarm and Warning limits for process monitor signals.

The table below describes the difference between Alarms and Warnings.

If the signal exceeds...

then...

the Alarm limits

  • an alarm sounds

  • an alarm message is displayed

  • the process is paused (i.e. the method execution is suspended and all pumps are stopped)

  • the alarm is noted in the logbook.

The situation must be acknowledged and corrected before the process can be continued.

the Warning limits

  • a warning message is displayed

  • the process continues

  • the warning is noted in the logbook.

Note: The message text in an Alarm dialog box and the corresponding text in the logbook are both color-coded in red. Warning texts are color-coded in orange both in the dialog box and in the logbook. The text in the logbook is changed into black when the Alarm or Warning is acknowledged.

Note: The Alarms are not active unless the mode is set to Enabled.

Alarms in a network

Alarms and warning messages are displayed on all stations with a connection to the concerned system. This is regardless of the activity that is currently performed in UNICORN and regardless of the identity and access rights of the current user.

Alarms and warnings can only be acknowledged from the station that is connected in control mode.

The hysteresis setting

The hysteresis setting (not available for ÄKTAdesign systems) for a warning determines to which extent the signal can oscillate up or down from the warning limit threshold without re-activating a warning.

After the signal has activated a warning, the warning will not be repeated as long as the signal remains within a window defined by the hysteresis setting above and below the warning limit. This prevents repeated warnings from noisy or oscillating signals close to the warning boundary.

Note: Hysteresis is only relevant for warnings, since an alarm puts the system into Pause mode at the first alarm.

2005-06-15