Siemens siprotec 7SA522, User Manual

Page: 88 / 628

SIPROTEC
®
4 Devices
4-24
7SA522 Manual
C53000-G1176-C119-2
4.9 Programmable Logic CFC
The CFC program in DIGSI
®
4 can be used to create additional logic in SIPROTEC
®
4 devices. For example, special interlocking conditions for controlled equipment can
be designed. Limit checks for measured values can be created, and corresponding
control can be designed.
SIPROTEC
®
4 devices may have some CFC functions set at the factory, according to
the type and version of the device.
User-defined CFC functions are done in graphical form. Generic logic modules (AND,
OR, NAND, etc.) and analog modules that are specially created for the requirements
of process control engineering (e.g., MAX, MIN, etc.) are available.
The CFC-modules are combined to form complete CFC-logic functions in order to
q
perform system-specific checks (e.g. interlocking),
q
generate messages if measured values approach a critical value, or
q
build group messages for transfer to a substation control systems.
k4122.gif
Figure 4-19 DIGSI
®
4, CFC basic options — example
CFC Designing Figure 4-20 shows the graphical nature of the CFC logic tool, and some of the com-
ponents that can be used to build the logic.
Details about designing with the CFC program can be found in the instruction book,
order number E50417-H1176-C098.
Note:
CFC settings are protected in DIGSI
®
4 by Password No. 7 (Password for parameter
set).