Glossary - Siemens Simatic S7-300 Technical Data Manual

Glossary

Accumulator
Accumulators represent CPU register and are used as buffer memory for download, transfer,
comparison, calculation and conversion operations.
Address
An address is the identifier of a specific address or address area. Examples: Input I 12.1;
Flag Word MW 25; Data Block DB 3.
Analog module
Analog modules convert process values (e.g. temperature) into digital values which can be
processing in the CPU, or they convert digital values into analog manipulated variables.
Application
An application is a program that runs directly on the MS-DOS / Windows operating system.
Applications on the PG include, for example, the STEP 5 basic package, GRAPH 5 and
others.
See User program
ASIC
ASIC is the acronym for Application Specific Integrated Circuits.
PROFINET ASICs are components with a wide range of functions for the development of
your own devices. They implement the requirements of the PROFINET standard in a circuit
and allow extremely high packing densities and performance.
Because PROFINET is an open standard, SIMATIC NET offers PROFINET ASICs for the
development of your old devices under the name ERTEC .
Backplane bus
The backplane bus is a serial data bus. It supplies power to the modules and is also used by
the modules to communicate with each other. Bus connectors interconnect the modules.
CPU 31xC and CPU 31x, Technical data
Manual, Edition 08/2004, A5E00105475-05
Glossary-1