Appendix 3. Operating Principles of the CPU Module
A-7
A.3 Operating Principles of the CPU Module
A.3.1 Operation of the CPU Module
ļ¬ Procedure
The operation of the CPU module is described below.
The CPU module is supplied with power.
The system enables the initialization.
ļ¬ The non-latched memory is initialized.
ļ¬ The user program is checked.
ļ¬ The parameters in the CPU module are checked.
ļ¬ The parameters in the module table are checked.
ļ¬ The module table in the CPU module is compared
with the actual I/O configuration.
ļ¬ The I/O setting is downloaded to the I/O module.
ļ¬ If the memory card is installed, whether to execute
the system copy procedure or not is checked.
Diagnosis processing:
ļ¬ The memory card and other setting are checked.
ļ¬ The I/O bus is checked.
ļ¬ The system parameter is checked.
The data sent to the I/O module is refreshed.
ļ¬ The data sent to the digital I/O module is refreshed.
ļ¬ The data sent to the analog I/O module is
refreshed.
ļ¬ The data sent to other modules are refreshed.
Program execution:
ļ¬ The user program is executed.
ļ¬ The interrupt subroutine is executed.
The data sent from the I/O module is refreshed.
ļ¬ The data sent from the digital I/O module is
refreshed.
ļ¬ The data sent from the analog I/O module is
refreshed.
ļ¬ The data sent from other modules are refreshed.
Communication service:
ļ¬ The communication through the CPU module
ļ¬ The communication through other I/O modules
ļ¬ The internal communication between the CPU
module and the I/O module