Rockwell Automation 1771-IFF/A,D17716.5.116 FAST ANALOG INPUT MODULE - Manual (Page 48)

Module Programming
5-4
Publication 1771Ć6.5.116 - July 1996
The PLC-5 program is very similar to the PLC-3 program with the
following exceptions:
1. You must use enable bits instead of done bits as the conditions on
each rung.
2. A separate control file must be selected for each of the block
transfer instructions. Refer to Appendix B.
Figure 5.3
PLCĆ5 Family Sample Program Structure
BTR Enable
EN
DN
Pushbutton
Power-up Bit
BTW Enable
1
2
Bit
ER
EN
DN
ER
BTR
BLOCK TRANSFER READ
RACK:
GROUP:
MODULE:
CONTROL:
DATA FILE:
LENGTH:
CONTINUOUS: N
BTW
BLOCK TRANSFER WRITE
RACK:
GROUP:
MODULE:
CONTROL:
DATA FILE:
LENGTH:
CONTINUOUS:
N
XX:XX
X
X
X
X
XX:XX
XX:XX
X
X
X
X
XX:XX
10956ĆI
Program Action
Rungs 1 and 2
At powerĆup, the program enables a
block transfer read and examines the
powerĆup bit in the BTR file (rung 1).
Then, it initiates one block transfer write
to configure the module (rung 2).
Thereafter, the program continuously
reads data from the module (rung 1).
A subsequent BTW operation is
enabled by a pushbutton switch (rung
2). Changing processor mode will not
initiate a block transfer write.
PLCĆ5 Programming