Allen-Bradley Logix5000 Reference Manual page 510

Chapter 13 Special Instructions (FBC, DDT, DTR, PID)
Example 1
7
0 0 0 1 1 1 1 1 1 1 1 1 1 1 1
0
0
Current Scan
Previous Scan
0
The rung remains false as long as the input
510
Example:
When enabled, the DTR instruction masks value_1. If there is a difference in
the two values, the rung-condition-out is set to true.
1 8 3
1 8 3
1 8 3
value does not change.
A 0 in the mask leaves the bit unchanged.
Rockwell Automation Publication 1756-RM003N-EN-P - October 2011
Example 2
Source
9 1
Mask = 0FFF
0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1
Reference
1
0
0 1
The rung remains true for one scan when a
change is detected.
8 7
8 7
Current Scan
Previous Scan
8 3
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