Toshiba GR200 Series Instruction Manual page 213

Common controls (CMNCTRL)
Double command blocking (DCB)
3.4.1
For control functions, the operating principle is that priority is given to the first command
received and shall be executed first. In other words, successive commands received do not have
the right to run until the first command received has failed to complete its operation (that is,
the principle of double command blocking (DCB) is established). The principle is significant for
protection and control devices in the sub-station†. Figure 3.4-1 illustrates how each control
function generates a STSELD signal; the aggregation of STSELD signals is performed in the
CMNCTRL1 function. The resultant signal is output at PLC connection point "DCB SND OR".
The resultant signal is returned to the respective control function as feedback.
"From 61850
communication
"stVal" message 2
LEDR function
LEDR function
Reception of "DCB"
Figure 3.4-1 DCB operation in CMNCTRL1 function
†Note: Let us assume that the control function in IED-1 controls CB1, as shown in Figure
3.4-2. IEDs -2 to -10 are forbidden to operate their CBs throughout the period that
IED-1 is in operation.
In Figure 3.4-1, the CMNCTRL1 function generates a message denoted with the number
1; Figure 3.4-2 exemplifies that the IED-1 generates the "stVal" message 1. In addition, IEDs-
2 to -10 are also required to receive message 1, this is denoted with the number 2. For
IEC61850 communication, the "stVal" messages 1 and 2 are carried by GOOSE publish and
GOOSE subscribe. Thus, for all IEDs (i.e., IED-1 to IED-10 of Figure 3.4-2), it is required to
set the GOOSE publish destination corresponding to the message.
stVal message
1
IED-1
CB1
Figure 3.4-2 Sending and reception of stVal message
Figure 3.4-3 demonstrates how the GOOSE publish destination is set with regard to the
DCB message. The user is required to set the destination for each respective IED by selecting
510001 0001011001 DCB RCV OR
Output of "StSeld"
LEDR01_STSELD
Ring LAN network constructed for the SAS
2 2
IED-2 IED-3
CB2 CB3
- 199 -
CMNCTRL1 function
To 61850
communication
DCB SND OR
≥1
To control functions
in its own
(510001 0008001F42)
2
IED-10
CB10
Centralized GRB200
(Soft: 030, 031, 032, 033, 034)
6F2S1931 (0.20)
"stVal" message 1