Siemens SIMATIC S7-300 Hardware And Installation Manual page 236

Glossary
Interrupt, status
A status interrupt can be generated by a DPV1 slave and causes OB 55 to be
called on the DPV1 master. For detailed information on OB 55, see the Reference
Manual "System software for S7-300/400: System and Standard Functions"
Interrupt, time-of-day
The time-of-day interrupt belongs to one of the priority classes when processing
programs in SIMATIC S7. It is generated depending on a specific date (or daily)
and time-of-day (e.g. 9:50 or hourly, or every minute). A corresponding
organization block is then executed.
Interrupt, diagnostic
--> Diagnostic interrupt
Interrupt, Process
--> Process Interrupt
Interrupt, Delay
The delay interrupt belongs to one of the priority classes when processing
programs in SIMATIC S7. It is started on expiration of a time generated in the user
program. A corresponding organization block is then executed.
Interrupt, watchdog
A watchdog interrupt is generated periodically by the CPU in configurable time
intervals. A corresponding --> organization block is then executed.
Analog Module
Analog modules convert process values (e.g. temperature) into digital values, so
that they can be processed by the central processing unit, or convert digital values
into analog manipulated variables.
START-UP
RESTART mode is activated on a transition from STOP mode to RUN mode. Can
be triggered by the --> mode selector switch or after power on, or by an operator
action on the programming device. An S7–300 performs --> a restart.
13-2
S7-300 Programmable Controller Hardware and Installation
A5E00105492-02