Program Management; Kinds Of Programs; Program Composition - Toshiba V Series User Manual

Chapter 3 Checking Switches

3.4 Program Management

3.4.1

Kinds of programs

3
3.4.2

Program composition

88
The L1 has main scan programs. Scan programs are repeated on a specific cycle, which
can be set as desired.
Type of scan Purpose
Main scan To register normally used
programs
The program structure is of 3 layers consisting of a task, programs, and functions
(function blocks).
• The task represents the type of work (type of execution) and manages the programs.
• A program represents a unit of execution, and consists of standard instruction words
and an assembly of program components, that is, functions and function blocks.
• The functions have the meaning of a function in mathematics, and consist of prepared
instruction words and a function program of standard format to be created by the user
as desired. The former is called the standard function and the latter, the user function.
The user function may call other standard functions and standard function blocks.
• The function blocks have the meaning of an advanced function in mathematics, and
consist of advanced function instruction words available as standard components and
advanced function programs to be created by the user as desired.
The former is called the standard function block and the latter, the user function block.
The user function may call other standard and user function blocks and standard and
user functions.
Program
Task
Program
Table 3-1 Kinds of Programs
ID
Entry No.
symbol
MS 0 to 7
Program proper Function/function block
User
function
User function
block
User
function
User function
block
User function
block
User function
block
User
function
User
function
Figure 3-1 Program Organization
model 1000 Loop Controller L1 User's Manual - Basic Hardware
Remarks
Cycle: 50 to 5000 ms
(at 50 ms intervals)
Standard
function
Standard
function block
Standard
function
Standard
function block
Standard
function
Standard
function block