Examples Of Block-Transfer Ladder Logic - Allen-Bradley PLC-5 User Manual

7-14 Communicating with a PLC-5 Adapter Channel
Enter the following parameters in the
block-transfer instructions in the
supervisory processor.
Set the length to 0.
Use the remote I/O rack number for
which you configure the
adapter-mode processor.
Use the group and module numbers for
which the adapter-mode processor is
configured.
Condition the use of BTR data with a
"data valid" bit.
All address comments for contacts shown in
the following examples represent the set (1)
state of the bit in the PLC-5 processor.
You may have to execute the BTR in the
PLC-5 scanner channel twice if the BTR's
time delay is greater than 2-3 program
scans. If you do not run the BTR twice, the
BTR will read old data from the
adapter processor.
Publication 1785-UM012D-EN-P - July 2005
If you want to transfer controller-resident local I/O data of the adapter mode
controller channel to a supervisory controller or if you want to transfer data
from the supervisory controller to controller-resident local I/O of the adapter
mode controller channel, you must use MOV or COP instructions within the
adapter-mode controller channel to move the data in or out of the data file
used in the adapter block-transfer control file.

Examples of Block-Transfer Ladder Logic

Example Bidirectional Repeating Block Transfer in
PLC-5 Supervisory Controller
Read data from adapter-mode processor
BTR and BTW enable bits
BT17:15
BT17:10
EN
EN
Send data to adapter-mode processor
BTR and BTW enable bits
BT17:15
BT17:10
EN EN
Buffer read data from adapter-mode processor to work area
BTR Done Bit Data Not Valid Bit
BT17:10
DN
PLC-5 adapter-mode processor channel is configured as rack 2
I:020
10
BTR
BLOCK TRANSFER READ
RACK 2
GROUP 0
DN
MODULE 0
CONTROL BLOCK BT17:10
DATA FILE N7:100
0
LENGTH
CONTINUOUS N
BTW
BLOCK TRANSFER WRITE
RACK 2
GROUP 0
DN
MODULE 0
CONTROL BLOCK BT17:15
DATA FILE N7:200
0
LENGTH
N
CONTINUOUS
COP
COPY FILE
SOURCE #N7:100
DEST #N7:300
LENGTH 64
EN
ER
EN
ER