Siemens SIMATIC S7-400 Reference Manual page 447

Input delay
Parameter in STEP 7 for digital input modules. The input delay is used to suppress coupled
interference. Spurious pulses of 0 ms up to the selected input delay are suppressed.
The selected input delay is subject to a tolerance that can be found in the technical
specifications of the module. A high input delay suppresses longer spurious pulses, a lower
delay suppresses shorter spurious pulses.
The permitted input delay depends on the length of the cable between sensor and module. If,
for example, there are long unshielded cables to the sensor (over 100 m), a high input delay
must be set.
Integration time
The integration time is the reciprocal of the → interference frequency suppression in ms.
Interrupt
SIMATIC S7 recognizes 28 different priority classes that control the execution of the
user program. These priority classes include interrupts, such as hardware interrupts. When an
interrupt occurs, the operating system automatically calls an assigned organization block in
which the user can program the required reaction (for example, in an FB).
Interrupt reaction time
The interrupt reaction time is the time from the first occurrence of an interrupt signal to
executing the first statement in the interrupt OB. General rule: Higher priority interrupts are
serviced first. This means that the interrupt reaction time is extended by the program execution
time of the higher priority interrupts and interrupts with the same priority that were called earlier
(queue).
Linearity error
The linearity error indicates the maximum deviation of the measured/output value from the
ideal linear relationship between measured/output signal and digital value. This is specified as
a percentage related to the nominal range of the analog module.
Load memory
The load memory is part of a programmable module (CPU, CP). It contains the objects
generated by the programming device (local objects). It is implemented either as a plug-in
memory card or as integrated memory.
Local data
Local data is the data assigned to a → logic block that is declared in its → declaration section
or in its variable declaration. It includes the following (block-specific): Formal parameters,
→ static data, → temporary data.
S7-400 Automation System Module Data
Reference Manual, Ausgabe 11/2016, A5E00850736-08
Glossary
447