Rs422 And Fiber Interface; And Fiber Interface - GE L60 Instruction Manual

3.3 DIRECT INPUT/OUTPUT COMMUNICATIONS
To recover the Rx clock from the data-stream, an integrated DPLL (digital phase lock loop) circuit is utilized. The DPLL is
driven by an internal clock, which is 16-times over-sampled, and uses this clock along with the data-stream to generate a
data clock that can be used as the SCC (serial communication controller) receive clock.
The following figure shows the combined RS422 plus Fiber interface configuration at 64K baud. The 7L, 7M, 7N, 7P, and 74
3
modules are used in two-terminal with a redundant channel or three-terminal configurations where channel 1 is employed
via the RS422 interface (possibly with a multiplexer) and channel 2 via direct fiber.
AWG 24 twisted shielded pair is recommended for external RS422 connections and the shield should be grounded only at
one end. For the direct fiber channel, power budget issues should be addressed properly.
When using a LASER Interface, attenuators may be necessary to ensure that you do not exceed maximum
optical input power to the receiver.
WARNING
Connections shown above are for multiplexers configured as DCE (data communications equipment) units.
The figure below shows the combined G.703 plus Fiber interface configuration at 64K baud. The 7E, 7F, 7G, 7Q, and 75
modules are used in configurations where Channel 1 is employed via the G.703 interface (possibly with a multiplexer) and
Channel 2 via direct fiber. AWG 24 twisted shielded pair is recommended for external G.703 connections connecting the
shield to Pin 1A at one end only. For the direct fiber channel, power budget issues should be addressed properly. See pre-
vious sections for more details on the G.703 and Fiber interfaces.
When using a LASER Interface, attenuators may be necessary to ensure that you do not exceed Maximum
Optical Input Power to the receiver.
WARNING
3-32
~ 1a
~ 1b
~ 2b
COM
~ 2a
Tx1 +
~ 3a
Rx1 –
~ 3b
Tx1 –
~ 4b
Rx1 +
~ 6a
Shield
Tx2 Rx2
~ 8a
Figure 3–39: RS422 AND FIBER INTERFACE CONNECTION
~ 1a
Shield
~ 1b
Tx –
2a
~
Rx –
~ 2b
Tx +
~ 3a
Rx +
3b
~
Tx2
Rx2
Figure 3–40: G.703 AND FIBER INTERFACE CONNECTION
L60 Line Phase Comparison Relay

3.3.6 RS422 AND FIBER INTERFACE

Clock
(channel 1)
RS422
channel 1
Fiber
channel 2
Surge
842777A1.CDR
3.3.7 G.703 AND FIBER INTERFACE
G.703
channel 1
Surge
Fiber
channel 2
842778A1.CDR
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GE Multilin