ADAM CPU 821x
Chapter 3 Deployment of the CPU 821x
ADAM 8000 Manual CPU 821x – Rev 1.1
3-13
Operating modes
The CPU can be in one of 3 operating modes:
•
STOP
•
START-UP
•
RUN
Certain conditions in the operating modes START-UP and RUN require a
specific reaction from the system program. In this case the application
interface is often provided by a call to an organization block that was
included specifically for this event.
•
Processing of the application program has stopped.
•
If the program was being processed, the values of counters, timers, flags
and the contents of the process image are retained during the transition
to the STOP mode.
•
Outputs are inhibited, i.e. all digital outputs are disabled.
•
RUN-LED
off
•
STOP-LED on
•
During the transition from STOP to RUN a call is issued to the start-up
organization block OB100. The length of this OB is not limited. The
processing time for this OB is not monitored. The start-up OB may issue
calls to other blocks.
•
All digital outputs are disabled during the start-up, i.e. outputs are
inhibited.
•
RUN-LED blinks
•
STOP-LED off
When the CPU has completed the start-up OB, it assumes the operating
mode RUN.
•
The application program in OB1 is processed in a cycle. Under the
control of alarms other program sections can be included in the cycle.
•
All timer and counters being started by the program are active and the
process image is updated with every cycle.
•
The BASP-signal (outputs inhibited) is deactivated, i.e. all digital outputs
are enabled.
•
RUN-LED on
•
STOP-LED off
Outline
Operating mode
STOP
Operating mode
START-UP
Operating mode
RUN
