Rockwell Automation 1771-IFE , D17716.5.90 USER MNL. ANALOG INPUT Module - Manual (Page 28)

Module Programming
Chapter 3
3-4
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 3.3
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