Triggering a list entry, Single bit, Least significant bit – Rockwell Automation 2711-ND3 PanelBuilder v2.60 Software User Manual User Manual
Page 199
12–19
Creating Bar Graphs, Indicators, Numeric Displays
Publication 2711-6.0
Triggering a List Entry
One of 3 data types can trigger the display of a list indicator entry:
•
Single Bit
•
Least Significant Bit
•
Value
Single Bit
Single Bit is only valid for a 2-entry indicator list. The highlighted
entry in a list is controlled by the status of a single bit. Turning the
tag address bit on/off toggles the highlight between the 2 list entries.
Least Significant Bit
The terminal highlights the entry corresponding to the Least
Significant Bit (LSB) at the tag address data words (0 to 254 bits).
Setting more than one bit at the tag address allows entries to display
in a priority sequence (state 0 is highlighted when bit 0 is ON, state 1
is highlighted when bit 1 is ON,..., state 254 is highlighted when bit
254 is ON).
An error state occurs when all bits are OFF (low). No entry in the
list is highlighted when an error occurs.
The controller program must clear the last bit displayed. The next
time the terminal reads the tag address, the list entry corresponding
to the next least significant bit is highlighted. The example below
shows what happens if bits 1 and 24 are set at tag address N7:2.
0
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Controller Program Clears Bit 1
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
24
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
24
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
24
State 0
State 1
State 2
State 3
State 25
State 24
State 26
State 27
Tag Address N7:3=256
Tag Address N7:3=256
Tag Address N7:3=256
Tag Address N7:2=2
Tag Address N7:2=0
Tag Address N7:2=0
State #1 Displayed
State #24 Displayed
Value
The controller triggers a list entry when the tag address contains a
specific value. The entry is highlighted until the value at the tag
address changes.