Advertisement
Control level and control point
3.3.1
As shown in Figure 3.3-1, the control hierarchy is distributed across three levels; the network
level having a remote-control center (RCC); the station level having operator and engineering
work stations (OWS/EWS); and the bay level† having an IED equipped with an LCD screen.
One of the three control-points (RCC, OWS/EWS, and LCD) is available to issue a control-
command.
†Note: We, hereafter, discuss only the operations at the bay level; that is, we focus only
on operations made from the bay level. The scope of this discussion does not
include operations from either the remote control center or the network levels.
Selector switches and bay operations
3.3.2
At the bay level, the 43BCU switch opens a path to permit the flow of the control-right.
LCD operation
(i)
When the user sets the 43BCU switch to "Local (L)", the issuing of a control-command from
the LCD is possible for the device.
RCC, EWS, or OWS operation
(ii)
Alternatively, suppose that the position "Remote (R)" is selected at the 43BCU switch. In this
case, the issuing of the control-command from the LCD is not possible.
Programming of control-right distributions
3.3.3
Figure 3.3-2 illustrates that the PLC function provides the means to distribute the control-
right for the control functions.
The part ○
1
distributed to the respective control applications. With regard to the LEDR function, PLC
connection point "LEDR01_CTRL_RIGHT" has been programmed using DOUT_BOOL feature
(for example). Therefore, the control-right signal is transferred to the select and operate-
condition logic‡ when the user connects the control-hierarchy with the LEDR function using
"LEDR01_CTRL_RIGHT".
‡Note: The select-condition and operate-condition logic are used to decide upon the
execution of a select command or an operate command in the LEDR function. For
more detail, see Chapter 3.4.1(iii) and 3.4.3(iii). As per the LEDR function, other
functions, such as DPOS, has the same logic itself; hence, the user is required to
do the connection.
and ○
logics are programmed so that, the control-right signal can be
2
- 363 -
6F2T0207 (0.01)
GRE200 (5,6)
Advertisement
