Rockwell Automation 1785-Lxxx Enhanced and Ethernet PLC-5 Programmable Controllers - Manual (Page 66)

Publication 1785-UM012D-EN-P - July 2005
4-22 Addressing I/O and Controller Memory
Optimizing Instruction Execution Time and Controller Memory
TIP
For the best instruction-execution performance, store your
most frequently used addresses as shown below:
output image
input image
status
binary, timer, counter, control,
integer, floating point
File Type
PLC-5/30
Physical Word # Default File #
0 0-63
1 32-127
2
3-999
according to your
application
PLC-5/40, -5/40L
-5/40E
0-127
32-255
PLC-5/60, -5/60L
-5/80, -5/80E
0-191
32-383
PLC-5/11,
-5/20, -5/20E
0-31
32-63
block transfer, message, PID,
SFC status, ASCII string
Physical Word # Physical Word # Physical Word #
The minimum size of the file is 32 words.
The status file is always the last physical file in the data table.
word 256
word 2048
frequently
used bit
addresses
frequently
used
element
addresses
Address bit instructions between the end of the input image file and physical word 256.
Bit addresses located in words greater than 256 require one extra word in the
controller's memory for storage and execute 0.16ms slower than bit addresses stored in
words 0-255.
Address element instructions between the end of the input image and physical word 2048.
Addresses stored in words greater than 2048 require more words in the
controller's memory for storage.
2
1
2
1
1