Rockwell Automation 1747-BSN Backup Scanner Module - Manual (Page 108)

Publication 1747-UM010B-EN-P - September 2003
6-12 Module Control and Status Word
Program File 4
0000
MOV
Move
Source
M0:1.3410
?<
Dest
B3:5
0000000000000000<
MOV
MOV
Move
Source
#M1:1.3410
?<
Dest
#B3:6
0000000000000010<
MOV
0001
B3:5
0
B3:6
0
COP
Copy File
Source
#N12:0
Dest #M0:1.3500
Length
128
COP
L
B3:7
0
0002
B3:6
0
U
B3:7
0
0003
B3:5
1
B3:6
1
COP
Copy File
Source #N12:128
Dest
#M0:1.3628
Length 128
COP
L
B3:7
1
0004
B3:6
1
U
B3:7
1
0005
MOV
Move
Source
B3:7
0000000010001000<
Dest
M0:1.3410
?<
MOV
0006 END
The following rungs are meant to be executed only when this processor/1747-BSN is in the primary mode. When the 1747-BSN is acting as
the primary processor, this rung copies the DTCW and DTSW to an internal storage word (B3:5 and B3:6, respectively) within this SLC
processor.
Virtual And Actual DTSWs
This rung monitors the DTCW and DTSW bits for Data Block #1. When a transfer of data using Data Block #1
is not in progress, copy up to 128 words to the appropriate M-file location for Data Block #1 in the 1747-BSN
module.
Virtual DTSW Bit For
Data Block #1
Virtual DTHW Bit For
Data Block #1
Virtual DTCW Bit For Data Block #1
Unlatch the virtual DTCW bit for Data Block #1 when the comparable virtual DTSW bit is set by the
1747-BSN module to indicate that it has received the last Data Block #1. When B3:7/0 has been unlatched,
the 1747-BSN module is ready for the next data transfer via Data Block #1.
Virtual DTHW Bit For
Data Block #1
Virtual DTCW Bit For
Data Block #1
This rung monitors the DTCW and DTSW bits for Data Block #2. When a transfer of data using Data Block #2 is not in
progress, copy up to 128 words to the appropriate M-file location for Data Block #2 in the 1747-BSN module.
Virtual DTSW Bit For
Data Block #2
Virtual DTHW Bit For
Data Block #2
Virtual DTCW Bit For Data Block #2
Unlatch the virtual DTCW bit for Data Block #2 when the comparable virtual DTSW bit is set by the
1747-BSN module to indicate that it has received the last Data Block #2. When B3:7/1 has been unlatched,
the 1747-BSN module is ready for the next data transfer via Data Block #2.
Virtual DTHW Bit For
Data Block #2
Virtual DTCW Bit For
Data Block #2
This rung copies the virtual DTCW (B3:7) to the actual DTCW (M0:1.3410) located in the 1747-BSN module.
M-file acesses are interrupts to the processor. Using virtual words minimizes M-file accesses, thereby
minimizing the effects of these transfers on the ladder program scan time.
Virtual And Actual DTCW