Ladder logic program, Figure 5.6 – Rockwell Automation 20-COMM-R Remote I/O Adapter User Manual
Page 72
5-14
Using Block Transfer Messaging
20-COMM-R Remote I/O Adapter User Manual
Publication 20COMM-UM004D-EN-P
Block Transfers are handled differently in the SLC 500 controller and
require the following data for the example program.
Formatting Block Transfer Messages on page 5-2
for more information
on block transfer messages.
Ladder Logic Program
Figure 5.6 SLC 500 Example Ladder Logic for Block Transfer Messaging
Address
Value (decimal)
Description
N12:1
20
Block Transfer Write Length
N12:2
100
Rack 1, Group 0, Slot 0
N13:1
20
Block Transfer Read Length
N13:2
100
Rack 1, Group 0, Slot 0
This rung executes once each time the SLC is switched into RUN mode. It resets any BTW control bits that might be set in the RIO
scanner.
0000
S:1
15
First Pass
MOV
Move
Source
0
0<
Dest
N12:0
0<
MOV
COP
Copy File
Source
#N12:0
Dest
#M0:1.300
Length
74
COP
This rung transfers the Block Transfer Write (BTW) status buffer from the RIO scanner to the memory in the SLC. When the BTW is
complete, the data in this file will indicate if the BTW was successful or not.
0001
COP
Copy File
Source
#M1:1.300
Dest
#N12:100
Length
74
COP
This rung enables the messaging BTW.
0002
N7:2
0
User
ENABLE MESSAGE
Input
OSR
B3:0
1
L
B3:0
0
Message
ENABLE
Bit
This rung enables a single BTW and then turns off the Message ENABLE bit.
0003
B3:0
0
Message
ENABLE
Bit
I:1.8
9
1747-SN
Message
BT Write
Available
I:1.8
10
1747-SN
Message
BT Read
Available
L
N12:0
15
Message BTW
BT EN (Enable)
U
B3:0
0
Message
ENABLE
Bit
This rung transfers the BTW information to the RIO scanner for execution.
0004
COP
Copy File
Source
#N12:0
Dest
#M0:1.300
Length
74
COP