Glossary
Glossary-10
ET 200S Interface Module IM 151/CPU
A5E00058783-01
Restart
When a CPU is started up (e.g. by switching the mode selector from STOP to
RUN or by switching the power on), the organization block OB 100 (complete
restart) is executed before cyclic program scanning (OB 1) commences. On a
complete restart, the process image input table is read in and the
STEP 7
user
program is processed starting with the first command in OB 1.
Runtime Error
Error which occurs during processing of the user program on the programmable
controller (i.e. not in the process).
Scan Cycle Checkpoint
The point during CPU program scanning at which the process image is updated,
for example.
SFC System Function
Slave
A slave can only exchange data with a master when requested by it to do so.
By slaves we mean, for example, all DP slaves such as ET 200S, ET 200B, ET
200X, ET 200M, etc.
Stand-Alone Operation
The device is operated on a stand-alone basis without data exchange to a
superordinate master and without direct communication with other DP slaves. All
the modules power up using default parameters and with the maximum
configuration (32 slots, 64 bytes consistently).
Start Event
Start events are defined events such as faults, time stamps or interrupts. They
cause the operating system to start a corresponding organization block (if
programmed to do so by the user). The start events are displayed in the header
information of the corresponding OB. The user can respond to start events in the
user program.