1MRK505382-UEN Rev. K
If you use an S7FTP patch cable for ethernet, be aware that a cross-connected cable has only pairs
on pin 1-2 and 3-6 cross-connected. The two remaining pairs are not cross-connected.
Clock configuration switch
As of transceiver 21-216 revision 2, a rotary switch is added to the front panel to ease installation and
testing (see Figure 73).
When two transceivers 21-216 are used in a PDH system, they are set as slaves when an external
clock is used.
Clock synchronization configuration
The rotary switch on the front panel has 16 positions (HEX switch). At position 0 the switch's arrow,
visible through the adjusting hole, points straight down (see Figure 73). In this position, external clock
is selected (default).
IEC07000249 V1 EN-US
Figure 73:
Position
0
1
2
3
4–7
8–15
Back-to-back testing
When performing back-to-back testing with G.703 ports directly connected, one transceiver 21-216 is
set as a master (internal clock).
5.5.4
Power-up and LED statuses with transceiver 21–216
To power up transceiver 21–216, connect the power cord to the transceiver, and then connect the
other end of the cord to mains. If the link does not work, try to cross-connect the fibre at one end.
There are 12 LED indicators on the front panel.
Communication set-up, 670/650 series
Application Guide
Rotary switch for clock synchronization configuration
Function
External clock is selected (slave)
External clock is selected and inverted (slave)
Internal clock is selected (master)
Internal clock is selected and inverted (master)
Reserved for future use
Reserved for factory testing
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IEC07000249-1-en.vsdx
Section 5
Communication set-up
GUID-13DA5C8C-39C3-4643-87BF-31B9428DF496 v1
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