Plc 5 Family Processors - AB Quality ALLEN-BRADLEY 1791 User Manual

PLC 5 Family Processors

The following PLC-5 program is very similar to the PLC-3 program with
the following exceptions:
You must use enable bits instead of done bits as the conditions on each
rung.
Rungs 2 and 3 have been replaced with 1 rung.
A separate control file must be selected for each of the block transfer
instructions.
Figure 6.4
PLC 5 Family Sample Program Structure
BTR Enable BTW Enable
1
Pushbutton
2
Powerup Bit
BTR
Enable
3
Note: In rungs 2 and 3 the BTW instructions would have the same data files, but different control files.
* Length = (number of outputs + 1) words.
Chapter 6
Programming Your Analog Module
BTR
BLOCK XFER READ
RACK:
GROUP:
MODULE:
CONTROL:
DATA FILE:
LENGTH:
CONTINUOUS:
BTW
Enable
BTW
BLOCK XFER WRITE
RACK:
GROUP:
MODULE:
CONTROL:
DATA FILE:
LENGTH:
CONTINUOUS:
BTW
Enable
BTW
BLOCK XFER WRITE
RACK:
GROUP:
MODULE:
CONTROL:
DATA FILE:
LENGTH:
CONTINUOUS:
EN
X
X
DN
X
XXX:XX
ER
XXX:XX
00
N
EN
X
X
DN
X
XXX:XX
ER
XXX:XX
00
N
EN
X
X
DN
X
XXX:XX
ER
XXX:XX
*
N
6-5