Toshiba GR200 Series Instruction Manual page 523

(2.36-1).
The delay difference (T dd ) between sending and receiving is determined with Equation
(2.36-2); you should set the difference (T dd ) as zero in all the IEDs when the upstream and the
downstream are carried out with the same route. On the other hand, suppose the route
between the upstream and the downstream is divided and their propagation times are different,
you are required that the values of T dd in all the IEDs are identical. Note that the T dd should
be less than 6000µs (6ms). When the user wishes to set T dd for the IED channel#1, use setting
[CH1_TCDT]. Likewise, the settings of other channels are treated as same to the channel#1
setting.
When three IEDs are operated on lines, their communications are linked as shown in
Figure 2.36-6. When IED_G is set as the master seen from Figure 2.36-3, the synchronization
control is performed between the master IED_G and the slave IED_H; likewise, the
synchronization control is performed between the master IED_G and the slave IED_R. The
slave IED_H and the slave IED_R both carry out the follow-up control with their channel#2.
Figure 2.36-6 Communication link in three terminal lines
Sampling address synchronization
(iii)
Once the synchronization between IEDs is established, all the IEDs start sampling address
synchronization function. This principle is shown in Figure 1.1-8; and this function is to make
symmetrical sampling addresses in the eniter IEDs. Keep in mind here that the sampling is
synchronized in the entire IEDs.
( �� ) + ( ��
− ��
�� ��
∆T =
T = T
dd d1
Terminal G
CH1
IED G
CH2
Master
- 500 -
)
− ��
��1 ��2
2
− T
d2
CH1 CH2
IED R
Slave
Terminal R
6F2S1914 (0.49)
(2.36-2)
(2.36-3)
Terminal H
CH1
IED H
CH2
Slave
GRL200 (Soft 033 & 037)