Rs422 Interface - GE UR Series Instruction Manual

3 HARDWARE
returned as G.703 data. Because of the complete split in the communications path and because, in each case, the clocks
are extracted and reconstructed with the outgoing data, in this mode there must be two independent sources of timing. One
source lies on the G.703 line side of the interface while the other lies on the Differential Manchester side of the interface.
The following figure shows the RS422 2-Terminal interface configuration at 64K baud. For 2-Terminal configurations, chan-
nel 2 is not used. AWG 22 twisted shielded pair is recommended for external connections. This interface module is pro-
tected by surge suppression devices which optically isolated.
Shield Termination
The shield pins (6a and 7b) are internally connected to the ground pin (8a). Proper shield termination is as follows:
Site 1: Terminate shield to pins 6a and/or 7b.
Site 2: Terminate shield to 'COM' pin 2b.
The clock terminating impedance should match the impedance of the line.
NOTE
The following figure shows the typical pin interconnection between two RS422 interfaces. All pin interconnections are to be
maintained for a connection to a multiplexer.
RS422
CHANNEL 1
CLOCK
SURGE
Figure 3–30: TYPICAL PIN INTERCONNECTION BETWEEN TWO RS422 INTERFACES
GE Power Management
W 3b
Tx -
W 3a
Rx -
RS422
W 2a
Tx +
CHANNEL 1
W 4b
Rx +
W
6a
Shld.
W 5b
Tx -
W
5a
Rx -
RS422
W
4a
Tx +
CHANNEL 2
W
6b Rx +
W
7b
Shld.
W
7a
+
CLOCK
W
8b
-
W 2b
com
W 8a
SURGE
RS422.CDR
p/o 827831A6.CDR
Figure 3–29: RS422 INTERFACE CONFIGURATION
W 3b
Tx -
W 3a
Rx -
W
2a
Tx +
W
4b
Rx +
W
6a
Shld.
W 7a
+
W
8b
-
W
com 2b
+
W 8a
64 KHz
L90 Line Differential Relay
3.3 L90 CHANNEL COMMUNICATION

3.3.5 RS422 INTERFACE

W 3b
Tx -
W 3a
Rx -
RS422
W
2a
Tx +
CHANNEL 1
W
4b
Rx +
W
6a
Shld.
W 7a
+
CLOCK
W
8b
-
W
2b com
W 8a
SURGE
831728A3.CDR
3
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