Technical data

Glossary
System Software for S7-300/400 System and Standard Functions- Volume 2/2
A5E00739858-01
Glossary-9
OB Priority
The operating system of the CPU differentiates between various priority classes,
for example, cyclic program processing, hardware interrupt- controlled program
processing. Organization blocks (OB) are assigned to each priority class, in which
the S7 user can program a reaction. The OBs have different priorities, which allow
them to be processed in the correct sequence when two occur at the same time
and allow OBs with higher priority to interrupt those with lower priority. The S7 user
can change the standard priorities.
Organization Block (OB)
Organization blocks form the interface between the CPU operating system and the
user program. The sequence in which the user program is processed is specified in
the organization blocks.
Parallel Structure
The parallel structure is a special type of signal processing in the controller
(mathematical processing). The P, I and D components are calculated parallel to
each other with no interaction and then totaled.
-
Linear
combination
LMN_I
SP
PV
+
TI = 0
TD = 0
GAIN = 0
INT
DIF
LMN_D
GAIN
X
LMN_P
PID_OUTV
Parameter
1. A parameter is a variable of an S7 logic block
(see block parameter actual parameter formal parameter)
2. A variable for setting the behavior of a module
(one or more per module)
Every configurable module has a basic parameter setting when it is supplied
from the factory, but this can be changed using STEP 7.
(one or more per module).
There are two types of parameter:
static and dynamic parameters parameter, static/ parameter, dynamic).