Siemens SIMATIC S7-300 Manual page 115

Global data
Global data can be addressed from any code block (FC, FB, OB). These include flag F,
inputs I, outputs Q, timers, counters and data blocks DB. Global data can be accessed either
absolutely or symbolically.
Global data communication
Global data communication is a method of transferring global data between CPUs (without
CFBs).
GSD file
The device data file (GSD file) contains all slave-specific properties. The format of GSD files
is specified in EN 50170, Volume 2, PROFIBUS.
Instance data block
The STEP 7 user program assigns an automatically generated DB to every call of a function
block. The instance data block stores the values of input, output and in/out parameters, as
well as local block data.
Integrated inputs/outputs for integrated technology
The Technology CPU has 4 digital inputs and 8 digital outputs integrated. You use these
inputs and outputs for technology functions, e.g. reference point acquisition (BERO) or high-
speed output cam switching signals. The integrated inputs and outputs can also be used with
technology functions in the
Integrated technology
In addition to the standard PLC functions, the Technology CPU has been expanded with
integrated technology functions. The operating system of the Technology CPU has also
been expanded in order to guarantee fast processing times for these technology functions.
Intelligent DP slave
Signal preprocessing field device. One of its features is that the input/output range provided
for the DP master does not correspond to an actually existing I/O, but an input/output range
that is mapped by a preprocessing CPU.
Interrupt
The CPU's operating system knows different priority classes for controlling user program
execution. These priority classes include interrupts, e.g. process interrupts. When an
interrupt is triggered, the operating system automatically calls an assigned OB. In this OB
the user can program the desired response (e.g. in an FB).
Load memory
Load memory is part of the CPU. It contains objects generated by the programming device. It
can be implemented either as a plug-in memory card or as integrated memory.
S7-300 CPU Data: CPU 315T-2 DP
Manual, 12/2005, A5E00427933-02
STEP 7
user program.
Glossary
Glossary-5