AB Quality Allen-Bradley 1771-IJ, User Manual

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6–9 Block Transfer Programming
Publication 1771ĆUM006B-EN-P - June 2002
PLCĆ5 Family Processors
You can use the following ladder logic with PLC-5 processors. This
program assumes that your application requires a single BTR and
BTW to pass data between the processor and the module.
Ladder logic alternates the execution of BTR and BTW instructions.
The processor checks data validity before accepting read data, and
sets one enable bit at a time.
Refer to Figure 6.7 for generalized ladder logic, and to Figure 6.8 for
example ladder logic with entered values.
Figure 6.7
Generalized Ladder Logic for PLCĆ5 Block Transfer
BTW
EN
BTR
EN
1
2
15047
BTW
Control Block
Data File
yyy
xxx
Continuous no
BTR
Control Block
Data File
aaa
zzz
Continuous no
BTW
EN
BTR
EN