Marathon Computer AACC 2000 manual Alarms

Marathon Monitors Inc.

Alarms

Alarm annunciation

Alarms are flashed as messages in the Home display. A new alarm is displayed as a double flash followed by a pause, old (acknowledged) alarms as a single flash followed by a pause. If there is more than one alarm condition, the display cycles through all the relevant alarm messages. Table 2-1 and Table 2-2 list all of the possible alarm messages and their meanings.

Alarm acknowledgement and resetting

Pressing both and at the same time will acknowledge any new alarms and reset any latched alarms.

Alarm modes

Alarms will have been set up to operate in one of several modes, either:

∙Non-latching,which means that the alarm will reset automatically when the Process Value is no longer in the alarm condition.

∙Latching, which means that the alarm message will continue to flash even if the alarm condition no longer exists and will only clear when reset.

∙Blocking, which means that the alarm will only become active after it has first entered a safe state on power-up.

Alarm types

There are two types of alarm: Process alarms and Diagnostic alarms.

Process alarms

These warn that there is a problem with the process which the controller is trying to control.

Alarm		What it means
Display
FSL	*	PV Full Scale Low alarm
_
FSH	*	PV Full Scale High alarm
_
dEv	*	PV Deviation Band alarm
_
dHi	*	PV Deviation High alarm
_
dLo	*	PV Deviation Low alarm
_
LCr	*	Load Current Low alarm
_
p.FLt		Probe impedance test
		fault.

Alarm		What it means
Display
FL2	*	Input 2 Full Scale Low
_		alarm
FH2	*	Input 2 Full Scale High
_		alarm
LOP	*	Working Output Low
_		alarm
HOP	*	Working Output High
_		alarm
LSP	*	Working Setpoint Low
_		alarm

*In place of the dash, the first character will indicate the alarm number.

Table 2-1 Process alarms

AACC 2000 Carbon 44 Nov. 1, 1997