Siemens SIMATIC S7-300 Manual page 120

Glossary
System memory
System memory is an integrated RAM memory in the CPU. System memory contains the
address areas (e.g. timers, counters, flags) and data areas that are required internally by the
operating system (for example, communication buffers).
Technology configuration data
The configuration that you have created with
configuration data.
Technology data block
The integrated technology provides current information on the status and on the values of
the technology objects via the technology data blocks.
Technology objects
Technology objects are the logical representation of axes, output cams, measuring inputs,
cams and external encoders, with which the drive components can be controlled. The
technology objects configured with the
definitions for the physical properties of the mechanical system, for limits, monitoring and
control.
Technology system data
Technology system data are the data of the technology objects, such as drive axis, output
cam, ...
Time-of-day interrupt
Interrupt, time-of-day
Timer
Times
Times
Times are part of CPU system memory. The content of "timer cells" is automatically updated
by the operating system, asynchronously to the user program. STEP 7 statements are used
to define the precise function of the timer cell (for example, ON delay) and to initiate their
execution (for example, start).
User memory
The user memory contains the code blocks and data blocks of the user program. User
memory can be integrated in the CPU, or stored on plug-in memory cards or memory
modules. However, the user program is principally processed from the working memory of
the CPU.
Glossary-10
STEP 7
is stored in the technology
SIMATIC S7-Technology
option package contain
S7-300 CPU Data: CPU 315T-2 DP
Manual, 12/2005, A5E00427933-02