Rockwell Automation 1747-BSN Backup Scanner Module User Manual

Page 77

Publication 1747-UM010B-EN-P - September 2003

Configuration and Programming 5-15

COP

Copy File
Source

#M1:1.100

Dest

#B3:0

Length

COP

Copy File
Source

#M1:1.110

Dest

#N10:0

Length

COP

MOVE

Source

B3:3

0000000000000000

Dest

N10:64

MOV

END

To decrease program scan time, copy the first four words of the M1 file to a binary file and use these addresses throughout the
program to access block transfer done, error, data, etc. information without interrupting the program scan many times.

Examine B3/13 (B3: 0/13), an internal storage bit, to determine when a block transfer is done. Note that examining multiple individual
M-file bits directly (every scan) can measurably increase processor scan time

Examine B3/12 (an internal storage bit) to determine if a BT error occurred. Buffer the BT status from B3:3 if an error does occur.

BT DONE

IMPORTANT

If you are using an SLC 5/02 processor, M file data
cannot be directly monitored. To monitor M files, you
must move the M file words into an SLC file that can
be monitored, e.g., an integer “N” file. SLC 5/03 or
later processors allow you to monitor M files directly.
However, do not address M file bits more than
necessary throughout your application program. The
processor accesses M files like immediate I/O.
Therefore, excessive addressing of M files can greatly
increase SLC processor scan time. For more
information on M files, refer to Appendix B.