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Publication 1766-RM001A-EN-P - October 2008
Chapter
11
Application Specific Instructions
This chapter contains general information about the application specific
instructions and explains how they function in your application program.
Each of the instructions includes information on:
•
what the instruction symbol looks like.
•
how to use the instruction.
These instructions simplify your ladder program by allowing you to use a
single instruction or pair of instructions to perform common complex
operations.
In this chapter you will find a general overview preceding groups of
instructions. Before you learn about the instructions in each of these
groups, we suggest that you read the overview that precedes each
section. This chapter contains the following overviews:
RHC - Read High Speed
Clock
Instruction Type: Output
Application Specific Instructions
Instruction
Used To:
Page
RHC
Provide a high performance time-stamp for performance
diagnostics and performing calculations such as velocity.
RPC
Copy the program checksum from processor memory or from the
memory module into the data table.
TDF
Calculate the number of 10 µs "ticks" between any two
time-stamps captured using the RHC instruction.
AB
S
Read High
S
peed Clock
Dest
N9
:
0
RHC
Execution Time for the RHC Instruction
Controller
Data Size
When Rung Is:
True
False
MicroLogix 1400
word
2.5910 µs
0.2150 µs
long word
3.1210 µs
0.1802 µs
efesotomasyon.com - Allen Bradley,Rockwell,plc,servo,drive
