GE D90 Plus Instruction Manual page 168

DIRECT INPUTS AND OUTPUTS
158
Figure 135: Direct input and output settings for IED 3
Plus
For UR -series IED 4:
Figure 136: Direct input and output settings for IED 4
Message delivery time is approximately 0.2 of power system cycle (at 128 kbps) multiplied
by the number of bridges between the origin and destination. Dual-ring configuration
effectively reduces the maximum communications distance by a factor of two.
In this configuration, the following delivery times are expected (at 128 kbps) when both
rings are healthy.
Table 9: Delivery times for healthy rings
Path
IED 1 to IED 2
IED 1 to IED 3
IED 1 to IED 4
IED 2 to IED 3
IED 2 to IED 4
IED 3 to IED 4
If one ring is broken (say TX2-RX2), then the delivery times are as follows.
Table 10: Delivery times for rings with break in TX2-RX2
Path
IED 1 to IED 2
Delivery time
0.2 of a power system cycle
0.4 of a power system cycle
0.2 of a power system cycle
0.2 of a power system cycle
0.4 of a power system cycle
0.2 of a power system cycle
Delivery time
0.2 of a power system cycle
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: COMMUNICATIONS