Siemens Simantic ET 200S Manual page 263

Equipotential bonding
Electrical connection (equipotential bonding conductor) that brings the exposed conductive
parts of electrical equipment and other conductive parts to the same or approximately the
same potential in order to prevent troublesome or dangerous voltages arising between these
parts.
ET 200
The ET 200 distributed IO system with the PROFIBUS DP protocol enables distributed IO
devices to be connected to a CPU or an appropriate DP master. A feature of the ET 200 is
its fast response times, since only a small amount of data (bytes) is transferred.
The ET 200 is based on IEC 61784-1:2002 Ed1 CP 3/1.
The ET 200 works on the master/slave principle. Examples of DP masters are the IM308-C
master interface or the CPU 315-2 DP.
DP slaves can be the distributed IO devices ET 200M, ET 200X, ET 200L, or ET 200S or DP
slaves from Siemens or other vendors.
FREEZE
This is a control command of the DP master to a group of DP slaves.
When a DP slave receives the FREEZE control command, it freezes the current status of the
inputs and transfers them cyclically to the DP master.
After each subsequent FREEZE control command, the DP slave freezes the status of the
inputs again.
The input data is not transferred from the DP slave to the DP master again cyclically until the
DP master sends the UNFREEZE control command.
Ground
The conductive mass of earth, the electrical potential of which is equivalent to zero. In the
vicinity of grounding electrodes, the potential may not be zero. The term "reference ground"
is often used here.
Grounding
Grounding means connecting an electrically conductive part to a grounding electrode by
means of a grounding system.
GSD file
The properties of a PROFINET device are described in a GSD (General Station Descriptor)
file that contains all required information for configuration.
As with PROFIBUS, you can link a PROFINET device in STEP 7 by means of a GSD file.
In PROFINET IO, the GSD file is always in XML format. The structure of the GSD file
corresponds to ISO 15734, the worldwide standard for device descriptions.
In PROFIBUS, the GSD file is in ASCII format (as defined in IEC 61784-1:2002 Ed1 CP 3/1).
ET 200S
Manual, Edition 10/2005, A5E00514527-01
Glossary
Glossary-3