MSA SUPREMA - Displaying and Cancelling Messages

REV 0, June 2005Page 40
Operation Manual SUPREMA
4. Operation of the System
4.2.2 Displaying and cancelling messages
The messages displayed using LED’s are divided into messages that affect the whole system
(SYSTEM) and messages that affect the measurement signals (SIGNAL).
SYSTEM:
• POWER: power supply on/off
• FAIL: system-specific error (e.g. defective CPU)
• INHIBIT: one or more inputs are inhibited or require calibration
SIGNAL:
• AL 1–AL 4: collective messages for the input alarms
(each input can trigger up to four alarms)
• FAIL: collective message for specific input problems
(measurement values that are over the full-scale range, measurement
values below the measurement range and signal failures)
Alarm types are latching or non-latching (also see Measure Points).
Non-latching alarms:
As soon as a new alarm is triggered, the corresponding LED flashes at a frequency of 0.5 Hz.
Pressing the ACKNL key makes the LED change to ‘steady state’. When the signal is within the
limits again, the LED will be extinguished, regardless of whether the alarm has been
acknowledged or not. For non-latching alarms, the RESET key has no effect.
Latching alarms:
As soon as a new alarm is triggered, the corresponding LED flashes at a frequency of 0.5 Hz.
Pressing the ACKNL key makes the LED change to ‘steady state’. When the signal is within the
limits again, the LED remains at ‘steady state’ if the alarm has been acknowledged, or in the
‘flashing state’ if the alarm has not yet been acknowledged. If the signal is within the limits
again and the alarm has been acknowledged, the LED is extinguished by pressing the RESET
key. If the signal is still beyond the limit, or if the alarm has not yet been acknowledged, pressing
the RESET has no effect.
Signals that are above full-scale or signal failures, are latched alarms. All signals that have
exceeded the limit values are latching alarms. Signals below the measurement range are non-
latched.
If an audible alarm device is connected to the system, it sounds as soon as a new alarm is
triggered. It continues to sound even when the alarm condition no longer exists. Pressing the
ACKNL key silences the horn, regardless of whether or not the alarm condition still exists. The
RESET key has no effect on the horn.
Note: When a redundant system is used, the RESET resp. ACKNL buttons have to
be pressed for at least 1 second.