Rockwell Automation 1747-BSN Backup Scanner Module - Manual (Page 155)

Publication 1747-UM010B-EN-P - September 2003
Programming Techniques 9-13
0029
B3:5
14
B3:6
14
COP
Copy File
Source
#N19:0
Dest #M0:1.5292
Length
128
COP
L
B3:7
14
0030
B3:6
14
U
B3:7
14
0031
B3:5
15
B3:6
15
COP
Copy File
Source #N19:128
Dest
#M0:1.5420
Length 128
COP
L
B3:7
15
0032
B3:6
15
U
B3:7
15
0033
MOV
Move
Source
B3:7
0000000010001000<
Dest
M0:1.3410
?<
MOV
0034 END
Virtual DTSW Bit
for Data Block #15
Virtual DTHW Bit for
Data Block #15
This rung monitors the DTCW and DTSW bits for Data Block #15. When a transfer of data using Data Block #15 is not in progress, copy
up to 128 words to the appropriate M-file location for Data Block #15 in the 1747-BSN module.
Virtual DTCW Bit for Data Block #15
Virtual DTCW Bit for Data Block #15 Virtual DTHW Bit for Data Block #15
Unlatch the virtual DTCW bit for Data Block #15 when the comparable virtual DTSW bit is set by the 1747-BSN module to indicate that it has
received the last data via Data Block #15. When B3:7/14 has been unlatched, the module is ready for the next data transfer via Data Block #15.
Virtual DTSW Bit
for Data Block #16
Virtual DTHW Bit for
Data Block #16
This rung monitors the DTCW and DTSW bits for Data Block #16. When a transfer of data using Data Block #16 is not in progress, copy
up to 128 words to the appropriate M-file location for Data Block #16 in the 1747-BSN module.
Virtual DTCW Bit for Data Block #16
Virtual DTCW Bit for Data Block #16
Virtual DTHW Bit for Data Block #16
Unlatch the virtual DTCW bit for Data Block #16 when the comparable virtual DTSW bit is set by the 1747-BSN module to indicate that it has
received the last data via Data Block #16. When B3:7/15 has been unlatched, the module is ready for the next data transfer via Data Block #16.
This rung copies the Virtual DTCW word (B3:7) to the actual DTCW word (M0:1.3410) located in the
1747-BSN module. M-file accesses 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 Word