Allen-Bradley Logix5000 Reference Manual page 307

Move/Logical Instructions (MOV, MVM, BTD, MVMT, BTDT, CLR, SWPB, AND, OR, XOR, NOT, BAND, BOR, BXOR, BNOT)
Description:
Arithmetic Status Flags:
Fault Conditions:
Condition
Prescan
Instruction first scan
Instruction first run
EnableIn is cleared
EnableIn is set
Postscan
Target 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0
Dest 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0
Source 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0
Dest 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
When enabled, the BTD instruction copies a group of bits from the Source to the
Destination. The group of bits is identified by the Source bit (lowest bit number of the
group) and the Length (number of bits to copy). The Destination bit identifies the lowest
bit number bit to start with in the Destination. The Source remains unchanged.
If the length of the bit field extends beyond the Destination, the instruction does not save
the extra bits. Any extra bits do not wrap to the next word.
Arithmetic status flags are affected
None
Execution:
Function Block Action
No action taken.
No action taken.
No action taken.
EnableOut is cleared, the instruction does nothing, and the
outputs are not updated.
The instruction executes.
EnableOut is set.
No action taken.
Example:
1. The controller copies Target into Dest.
2. The SourceBit and the Length specify which bits in Source to copy into
Dest, starting at DestBit. Source and Target remain unchanged.
Rockwell Automation Publication 1756-RM003N-EN-P - October 2011
Structured Text Action
No action taken.
No action taken.
No action taken.
N/A
EnableIn is always set.
The instruction executes.
No action taken.
DestBit
Chapter 7
SourceBit
307