GE D90 Plus Instruction Manual page 165

CHAPTER 6: COMMUNICATIONS
Direct inputs and outputs for interlocking busbar protection
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
Figure 126: Direct input and output settings for IED 1
Plus
For UR -series IED 2:
Figure 127: Inter-relay communications settings for IED 2
Figure 128: Direct input and output settings for IED 2
The message delivery time is about 0.2 of power cycle in both ways (at 128 kbps); that is,
from device 1 to device 2, and from device 2 to device 1. Different communication cards
can be selected by the user for this back-to-back connection (for example: fiber, G.703, or
RS422).
A simple interlocking busbar protection scheme can be accomplished by sending a
blocking signal from downstream devices, say 2, 3, and 4, to the upstream device that
monitors a single incomer of the busbar.
DIRECT INPUTS AND OUTPUTS
155