Triggering an indicator state, Single bit, Least significant bit – Rockwell Automation 2711-ND3 PanelBuilder v2.60 Software User Manual User Manual
Page 193
12–13
Creating Bar Graphs, Indicators, Numeric Displays
Publication 2711-6.0
Triggering an Indicator State
One of 3 data types can trigger the display of an indicator state:
•
Single Bit
•
Least Significant Bit
•
Value
Single Bit
Single Bit is only valid for 2-state multistate indicators. The state is
controlled by the status of a single bit. Turning the tag address bit on
or off toggles the indicator display between state 0 and state 1.
Least Significant Bit
The terminal displays the state corresponding to the Least Significant
Bit (LSB) at the tag address data words (0 to 1,999 bits). More than
one bit may be set at the tag address allowing states to display in a
priority sequence (state 0 displays when bit 0 is ON, state 1 displays
when bit 1 is ON, ..., state 1,999 displays when bit 1,999 is ON).
An error state occurs when all bits are OFF (low). The message
defined for the error state (State E) displays, if defined. The default
message is “Error”.
The controller program must clear the last bit displayed. The next
time the terminal reads the tag address, the state corresponding to the
next least significant bit is displayed. The following example 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
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 #1 Displayed
State #24 Displayed
Tag Address N7:2=2
Tag Address N7:2=0
Tag Address N7:2=0
Tag Address N7:3=256
Tag Address N7:3=256
Tag Address N7:3=256
1
Value
The controller triggers a state when the tag address contains a
specific value. The specified state is displayed until the value at the
tag address is changed.