Rockwell Automation 1785-LTx,D17856.2.1 Classic PLC-5 Programmable Controllers Users Manual - Manual (Page 124)

Calculating Program Timing
Chapter 9
9-7
The time it takes for a processor to scan an instruction depends on the type
of instruction, the type of addressing, the type of data, whether the
instruction has to convert data, and whether the instruction is true or false.
This section provides timing and memory requirements estimates with
these assumptions:
direct addressing
integer data, except where noted
no data-type conversions
addresses within the first 4096 words of the data table of a PLC-5/10,
-5/12, -5/15, or -5/25 processor
execution times shown in
µ
s
Memory requirements refer to the number of words the instruction uses. In
some cases, an instruction may have a range of memory requirements. The
range of words exists because the instruction can use different types
of data.
Important: The tables are divided into instruction times and memory
requirements that are specific to PLC-5/10, -5/12, -5/15, and -5/25
processors.
Instruction Timing and
Memory Requirements