Siemens Simatic S7-400 - Manual (Page 613)

Glossary
Glossary-7
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
Function
A function (FC) in accordance with IEC 1131-3 is a
³
code block without
³ static data. A function allows parameters to be passed in the user program.
Functions are therefore suitable for programming complex functions, such as
calculations that are frequently repeated.
Functional grounding
Grounding which has the sole purpose of safeguarding the intended function of
the electrical equipment. Functional grounding short-circuits interference voltage
that would otherwise have an impermissible impact on the equipment.
Function block
A function block (FB) in accordance with IEC 1131-3 is a
³
code block with
³ static data. Because an FB has a memory, its parameters (outputs, for
example) can be accessed from any position in the user program.
Fuse blown
Parameter in STEP 7 for digital output modules. When the parameter is enabled,
the failure of one or more fuses is detected by the module. With corresponding
parameter assignment, a
³
diagnostic interrupt is triggered.
Global data
Global data are data that can be addressed from any
³
code block (FC, FB,
OB). In detail, this refers to bit memories (M), inputs (I), outputs (Q), timers,
counters and data blocks (DB). Absolute or symbolic access is possible to global
data.
Global data communication
Global data communication is a method of transferring
³
global data between
CPUs.
Ground
The ground is the total number of all the interconnected inactive parts of a device
that cannot take on a hazardous voltage in the event of a fault.
Ground
The conductive ground whose electric potential can be set to zero at any point.
In the proximity of grounding electrodes, the ground can have a potential other
than zero. The term ”reference ground” is frequently used to describe such
circumstances.