Rockwell Automation 1336-GM1 Remote I/O Communications Module - Manual (Page 55)

Using Block Transfer Messages 5–3
Understanding Data Storage In order to use the block transfer instructions in the ladder program, it
is necessary to reserve several words for data storage. Some of these
words are required for internal use by the block transfer function, and
some contain the block transfer message information. Refer to
Appendix B for detailed information on the required data in data files
for different block transfer messages.
Example PLC Block Transfers Figure 5.3 and Figure 5.4 are examples of block transfer
programming from PLC controllers to a Remote I/O communications
module. The BTW_AVAIL and BTR_AVAIL bits from the module
status word (I:010 in these examples) are used in these examples. The
examples also show how user logic can be used to enable or disable
the block transfer operations.
Figure 5.3 Example for a PLC-5/15 or PLC-5/25
This rung performs a Block Transfer Write to the 1203-GD1 at Rack Address 1, Starting Group 0
(the Module number is always 0 with these adapters). The data instructs the adapter to send a SCANport message.
When this message has completed, the response can be read with a BTR.
0000
B3:0
0
User
Logic
I:010
15
BTW
Available
I:010
12
BTR
Available
EN
DN
ER
BTW
Block Transfer Write
Module Type Generic Block Transfer
Rack
001
Group 0
Module 0
Control Block N11:0
Data File N12:0
Length 64
Continuous No
BTW
This rung performs a Block Transfer Read from the 1203-GD1 at Rack Address 1, Starting Group 0
(the Module number is always 0 with these adapters). The response contains the data read from the SCANport
Product (as instructed by the previous BTW).
0001
I:010
12
BTR
Available
EN
DN
ER
BTR
Block Transfer Read
Module Type Generic Block Transfer
Rack
001
Group 0
Module 0
Control Block N11:5
Data File N12:70
Length 64
Continuous No
BTR
0002 END