Rockwell Automation 1747-BSN Backup Scanner Module - Manual (Page 186)

Publication 1747-UM010B-EN-P - September 2003
B-6 M0-M1 Files and G Files
SLC 5/03 Processor Example
The SLC 5/03 processor access times depend on the instruction type.
Consult the table on page B-4 for the correct access times to add. As
an example, if you use a COP to M file instruction like the one shown
above, add 772 µs plus 23 µs per word. This adds 1554 µs to the
SLC 5/03 processor scan time due to the COP instruction.
SLC 5/04 and SLC 5/05 Processor Example
The SLC 5/04 and SLC 5/05 processors access times depend on the
instruction type. Consult the table on B-5 for the correct access times
to add. As an example, if you use a COP to M file instruction like the
one shown above, add 735 µs plus 23 µs per word. This adds 1517 µs
to the SLC 5/04 and SLC 5/05 processor scan time due to the COP
instruction.
Minimizing the Scan Time
You can keep the processor scan time to a minimum by economizing
on the use of instructions addressing the M0 or M1 files. For example,
XIC instruction M0:2.1/1 is used in rungs 1 and 2 of the figure below,
adding approximately 2 ms to the scan time if you are using an
SLC 5/02 Series B processor.
COP
Copy File
Source
#B3:0
Dest #M0:1.0
Length 34
COP
COP
Copy File
Source
#B3:0
Dest #M0:1.0
Length 34
COP
M0:2.1
1
B3
10
B3
10
B3
12
M0:2.1
1
XIC instructions in rungs 1 and 2 are
addressed to the M0 data file. Each of
these instructions adds approximately
1 ms to the scan time (SLC 5/02 Series B
Processor).