Toshiba 6F3B0253 user manual Scanning

6F3B0253

5. Operating System Overview

5.3 Scanning

The flowchart below shows the basic internal operations performed by the T1-16S from the time power is turned on through program execution. As the diagram shows, executing a program consists of continuous scanning operations. One scan is a cycle starting with the self-diagnosis and ending with the completion of peripheral support.

Power ON
Hardware check
Initial load
Register/device
initialization
Self-diagnosis
Mode	HALT mode
control
RUN mode
Register/device	At the first
initialization	scan
Scan	At the first
Program check
	scan
I/O update
Timer update
User program
execution
Peripheral
support

Power-up Initialization (approx. 1 s)

Scan cycle

Basic Hardware and Function 69