Using The Alarm Cutoff Feature; Forcing On Relays Or Led's - Emerson LMS1000 User Instructions

Section 5847
Issue AL, July 24, 2006

USING THE ALARM CUTOFF FEATURE

Note: This feature is not the same as the ACO provided on the MCA's Interface Pad of a
An Alarm Cut-Off Feature allows users to temporarily cut-off existing alarm conditions
from affecting certain relay channels of the system. This feature prevents any analog,
function, or binary channel alarm condition from affecting the control programs of the
relay channels. This feature is intended for applications where programmable relays are
being used as MAJOR and MINOR alarm relays. This feature must be programmed
when the relay channels are configured to be operable. It is important to know that if a
cut-off alarm clears, such as a low voltage going away, the cut-off feature for that alarm is
automatically released, or "uncanceled". That is, if the alarm were to turn in again, the
user must initiate another alarm cut-off to prevent that alarm from affecting the relay.
Activating the ACO: If a relay energizes due to an alarm condition active on an analog,
function, or binary channel; the user can "cut-off" (de-energize) the alarm by issuing the
command SET ACO. The system responds with a listing of alarms that are cancelled
and makes an entry in the event log. This command is available to users programmed
for access to level 4 commands.
Clearing the ACO:

FORCING ON RELAYS OR LED'S

Relay's and LED's are normally controlled by control programs. They can also be forced
on through the commands SET RLY and SET LED, respectively. If a relay or LED has
been manually forced on, it can be turned off through the commands CLR RLY and CLR
LED, respectively. You cannot turn off a relay or LED that has been turned on through a
control program. If a relay must be turned off in this situation, configure the associated
relay channel to be inactive.
Note: The relay circuit card contains a jumper which may be set to disable the use of the
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a) Manual: The command CLR ACO releases, or "uncancels", the alarm cut-off
feature thereby enabling analog, function, and binary channel alarm conditions to
again affect the relay channels' control programs. This command is available to
users programmed for access to level 4 commands. An entry is recorded in the
event log that tags a user's name to this action.
b) Automatic: Also, any relay channel configured to be "Affected by ACO" can also
be configured so that it can only remain cancelled for a selectable amount of
time. This is accomplished by setting the "cycle frequency" of the relay channel
for the desired time period. An alarm relay cancelled by the SET ACO command
is automatically reset by the system at a time determined by the relay's "cycle
frequency". Basically, the system uncancels all alarms by performing the
equivalent of a CLR ACO command each time that the total number of minutes in
a day (that have elapsed since midnight) is evenly divisible by the relay's "cycle
frequency". For example, a relay with a "cycle frequency" of 480 minutes cycles
off at midnight, 8 AM, and 4 PM. This feature is designed to automatically
restore cancelled major or minor alarm relays at selected time intervals.
SET RLY and CLR RLY commands.
Chapter 2. Operating LMS1000
Spec. Nos. 586505000 and 5865055000 (Model LMS1000)
User Instructions