Rockwell Automation 2711-ND3 PanelBuilder v2.60 Software User Manual - Manual (Page 241)

15–19 Creating Alarms
Publication 2711-6.0
Bit or LSBit Triggered Alarms
This section shows an alarm setup using a Bit type trigger. The
value/bit range for a bit trigger is 0 – 255 (bit, signed/unsigned
integer, BCD data types). For bit array, the range is the array size.
If using the Ack tag, the value/bit range begins with 1, instead of 0.
The following setup shows 3 alarms (A,B,C) assigned to the alm_tag
trigger. The Trigger Type is Bit. In this case, the Value/Bit field is a
bit offset from the Trigger Tag address (not a value).
In the Tag Editor, the trigger tag definition for alm_tag is:
Tag Name Data Type Tag Address Node Name
alm_tag Bit N15:0/0 SLC_1
This tag handles up to 256 consecutive bits/alarms (0 – 255),
N:15:0/0 to N15:15/15.
The controller address of the alarm trigger bit is the number in the
Value/Bit field plus the Trigger Tag address.
Trigger Tag Address + Value/Bit = Trigger Bit Address
•
Alarm C triggers when N15:0/1 changes from 0 to 1.
1 + N15:0/0 = N15:0/1
•
Alarm B triggers when N15:0/2 changes from 0 to 1.
2 + N15:0/0 = N15:0/2
•
Alarm A triggers when N15:0/3 changes from 0 to 1.
3 + N15:0/0 = N15:0/3
For the LSBit trigger, an alarm triggers when the trigger bit changes
from 0 to 1 and all other bits between the Trigger Tag address and
the trigger bit address are cleared. If the Trigger Tag address is
N7:12/4 and the Value/Bit is 6, an alarm is triggered when N7:12/10
changes from 0 to 1. It is the only bit set between N7:12/4 and
N7:12/10 inclusive.
If N7:12/4 is 1 when N7:12/10 changes to 1, the alarm corresponding
to N7:12/10 will not trigger until N7:12/4 is reset to 0.