CTC Union ET100/NRZ, User Manual

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ET100/NRZ LAN-WAN Bridge
The next example connects the pair of ET100/NRZ bridge units to existing NRZ transmission
equipment which already supplies the NRZ clock to the tributary equipment.
NRZ
Transmission
Equipment
TD
TC
RD
RC
RD
RC
TD
TC
NRZ Receive NRZ Receive
Figure 7: Point to Point, over existing NRZ equipment (recovery clock)
In this final example, the ET100/NRZ is operated without any dedicated clocking lines. In the point
to point example, one unit is configured with internal transmit clock and the data rate is set by DIP switch
for n x 64. The slaved unit uses PLL (Phase-Locked Loop) timing to recover the clock from the received
NRZ data stream. In environments where there may be long data streams of all zeros, the PLL recovered
clocking may not be stable. This can be corrected by enabling the "scrambling" function on both units. The
scrambling function will ensure that the data stream has adequate pulses for clock recovery by using
special line coding. Note: Both units must have the scrambling setting either enabled or disabled, or they
will not be able to communicate properly with each other.
TD
TC
RD
RC
RD
RC
TD
TC
Internal PLL Mode
Figure 8: Point to Point, without clock lines by using a PLL to recover clock
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