Toshiba 6F3B0253 - Manual (Page 71)

6F3B0253
Basic Hardware and Function
69
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
Self-diagnosis
Register/device
initialization
Mode
control
Register/device
initialization
Program check
I/O update
Timer update
User program
execution
Peripheral
support
Power-up
Initialization
(approx. 1 s)
HALT mode
Scan cycle
RUN mode
At the first
scan
At the first
scan
Scan