Rockwell Automation 2711 PANELBUILDER SOFTWARE USER MANUAL - Manual (Page 235)

Information and Alarm Windows
Chapter 7
7-27
Triggering Alarm Messages for Bit Position Data Type
To trigger a message, the PLC program must set the PLC bit that
corresponds to the desired message number in the Alarm Message List. If
the PanelView terminal detects any bit change from 0 to 1, the Alarm
window appears, containing the defined message. If the Alarm window is
not cleared by the operator, and additional alarm bits change from 0 to 1,
they will be listed in the order of occurrence. If more than one bit changes
from 0 to 1 during a single PLC I/O scan, the alarms will be listed in order
from lowest to highest message number. Avoid situations in which the
same alarm bit can keep toggling rapidly. The Alarm window would be
triggered repeatedly and the same message repeatedly listed.
Acknowledged Alarm Number Address
When you enable the Acknowledged Alarm Number Address, an address
definition window opens. You can define a PLC Input address that
PanelView will use to indicate to the PLC controller which alarms have
been acknowledged.
Data Type can be Binary, BCD or Bit
for Bit: When the user acknowledges an alarm from the Alarm
window or the Alarm History screen, the acknowledge bit
corresponding to the alarm (the first bit or start bit corresponds to
alarm 1; the 496th bit corresponds to alarm 496) is set to 1. This
acknowledged bit will remain on until the corresponding alarm is
triggered again, which in turn will reset the acknowledge bit to 0.
for Binary or BCD: When the user acknowledges an alarm from
the Alarm window or the Alarm History screen, the number of the
acknowledged alarm is put into the Acknowledged Alarm Number
Address. Pressing the Acknowl Alarm button on the Alarm
History screen when there are no unacknowledged alarms resets
the value of this address.
Number of Bits varies with the Data Type:
for Bit data type, the number of bits that can be assigned ranges
from 1 to 496
for Binary data type, the number of bits assigned can be from 1 to
16
for BCD data type, the number of bits must be a multiple of 4,
from 4 to 32