Configuration
5-32 7SJ62 Manual
C53000-G1140-C121-1
5.3 Creating User Defined Functions with CFC
General The 7SJ62 relay is capable of implementing user defined logic functions (PLC) which
may be processed by the relay. The CFC feature (C
ontinuous Function Chart) is need-
ed to process user defined protective functions and logic conditions (e.g. interlocking
conditions for switching devices) or to process measured values. Interlocking condi-
tions and command sequences, for example, may be programmed, using predefined
function modules, by persons without any specialized software programming abilities.
A total of 21 functional modules (FM), with which the desired functions may be com-
posed, are saved in a library. Detailed explanations are in the CFC manual, order
number E50417–H1176–C098, or in the DIGSI
®
4 manual, order number E50417–
H1176–C097.
The creation of a logical PLC function is performed by means of a PC using application
DIGSI
®
4 and transferred via the user or service interface. In order to create user de-
fined logic functions, the indications and measured values required by these functions
must first be configured in the matrix with CFC as the source or destination (see Sec-
tion 5.2).
CFC can be started by double-clicking on &)&. The names of all available CFC charts
will appear. The desired CFC chart for processing can be selected via a double-click
of the mouse. The CFC program will begin, and the chart will be displayed. If no chart
is available yet, you can create a new chart via the menu &UHDWH → &)&²&KDUW.
Run-Time Proper-
ties
The functions to be implemented in CFC may be divided into four task levels:
• Measured Values: This task is processed cyclically every 600 milliseconds
(09B%($5% = measurement value processing) and might becomes slower if device
is in pickup-stage.
• System Logic: Operation is triggered by events (i.e. these functions are processed
for each change of state at one of the inputs). System logic has lower priority than
a protection function and will be suppressed as soon as the relay picks up
(3/&B%($5% = slow PLC processing).
• Protective functions: These functions have the highest priority, and, like the system
logic functions, are event-controlled and processed immediately after a change of
state (3/&B%($5% = fast PLC processing).
• Switchgear Interlocking: This task is triggered by commands. In addition it is pro-
cessed cyclically approximately every second. It might becomes slower if device is
in pickup-stage (6)6B%($5% = interlocking).
The function to be implemented must be one of these four types. To implement a func-
tion from the 6HWWLQJV → &)& menu, activate the menu by selecting (GLW, and then
5XQ6HTXHQFH, and then the desired run-time level (See Figure 5-31).
Figure 5-31 Establishing the Task Level
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