Creating User Defined Functions With Cfc - Siemens SIPROTEC 7SJ62 Instruction Manual

Configuration
5.3

Creating User Defined Functions with CFC

General
Run-Time Proper-
ties
5-32
The 7SJ62 relay is capable of implementing user defined logic functions (PLC) which
may be processed by the relay. The CFC feature (Continuous 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
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.
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
5XQ 6HTXHQFH, and then the desired run-time level (See Figure 5-31).
Figure 5-31 Establishing the Task Level
®
4 manual, order number E50417–
C53000-G1140-C121-1
7SJ62 Manual