GE D90 Plus Instruction Manual page 74

ELECTRICAL INSTALLATION
64
Figure 34: RS422 interface connections
The following figure shows the typical pin interconnection between two dual-channel
RS422 interfaces. All pin interconnections are to be maintained for a connection to a
multiplexer.
Figure 35: Typical connection between two RS422 interfaces
Each channel of the RS422 interface accepts a clock input for transmit timing. It is
important that the rising edge of the 64 kHz transmit timing clock of the multiplexer
interface is sampling the data in the center of the transmit data window. Therefore, it is
important to confirm clock and data transitions to ensure proper system operation. For
example, the following figure shows the positive edge of the Tx clock in the center of the Tx
data bit.
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 3: INSTALLATION