Rockwell Automation 1747-BSN Backup Scanner Module - Manual (Page 145)

Publication 1747-UM010B-EN-P - September 2003
Programming Techniques 9-3
Program File 3
0000
MOV
Move
Source
M1:1.3410
?<
Dest
B3:3
0000001001100000<
MOV
0001
B3:3
0
COP
Copy File
Source #M1:1.3500
Dest
#N12:0
Length 128
COP
B3:4
0
0002
B3:3
1
COP
Copy File
Source #M1:1.3628
Dest
#N12:128
Length 128
COP
B3:4
1
0003
B3:3
2
COP
Copy File
Source #M1:1.3756
Dest
#N13:0
Length 128
COP
B3:4
2
The following rungs are meant to be executed only when this processor/1747-BSN is in the backup mode. When the 1747-BSN is acting
as the backup processor, this rung copies the DTSW (Data Table Status Word) to an internal storage word (B3:3) within the SLC processor.
This rung copies the "new" Data Block #1 data from the secondary 1747-BSN to a file within the secondary processor. When the copy is
complete, the DTHW (Data Table Handshake Word) for Data Block #1 (B3:4/0 = M0:1.3411/0) must be set to inform the secondary
1747-BSN that the secondary processor has received the latest Data Block and is now ready for the next block of data via Data Block #1.
This rung copies the "new" Data Block #2 data from the secondary 1747-BSN to a file within the secondary processor. When the copy is
complete, the DTHW (Data Table Handshake Word) bit for Data Block #2 (B3:4/1 = M0:1.3411/1) must be set to inform the secondary
1747-BSN that the secondary processor has received the latest Data Block and is now ready for the next block of data via Data Block #2.
This rung copies the "new" Data Block #3 data from the secondary 1747-BSN to a file within the secondary processor. When the copy is
complete, the DTHW (Data Table Handshake Word) bit for Data Block #3 (B3:4/2 = M0:1.3411/2) must be set to inform the secondary
1747-BSN that the secondary processor has received the latest Data Block and is now ready for the next block of data via Data Block #3.
Virtual DTHW bit for Data Block #1
Virtual DTHW bit for Data Block #2
Virtual DTHW bit for Data Block #3
Virtual and Actual DTSWs
Virtual DTSW bit for Data Block #1
Virtual DTSW bit for Data Block #2
Virtual DTSW bit for Data Block #3