Juniper CTP151 Platform, Hardware Manual, Page: 22 / 104

NOTE: Only ports 0 and 2 (the bottom two ports) on the front of the serial module can be used
for the multiservice features. You can configure direction, output high and low levels, and data
range for this module.
The four-port serial interface module supports individual cabling for each port. The CTP151 ports have
small serial ports for HD-26 26-pin connectors (see Figure 6 on page 11 ). The lowest-numbered port
(marked 0) is at the bottom left, and the highest-numbered port (marked 3) is at the top right.
Figure 6: CTP151 Serial Multiservice Interface Module
g100916
2 1
2
—
1
—
STATUS LED Four small serial ports and one clock reference port
The software-selectable interfaces for the module on all ports are RS-232/V.24, EIA530/X.21, EIA530A,
and V.35. Software-selectable rates range from 50 bps to 12.228 Mbps. On ports 0 and 2 there are also
options for 64Khz (4WTO) analog, high-quality analog, or IRIG.
The module also includes an external clock reference port (CLK) for an HD-26 connector. Note that only
one external clock reference is required even if there are two interface modules, serial or T1/E1.
On the CLK port, differential clock signals are output on the pins 4 and 17 of the HD-26 connector. When
an EIA-530A DCE-F serial cable (CTP150-CBL-DB25-DCE-F) is connected to the CLK port, the TT pins
24 and 11 of the DB25 connector output clock signals. If you configure a 32 kHz reference output, an
RS-422 32 kHz clock signal is generated on the pins. Even if you disable the 32 kHz reference output and
configure an external clock reference, the module expects an RS-422 clock input (of the configured
frequency) on the same pins.
NOTE: The external clock reference port must be used only on the module in slot 0, the left-most
slot on the front of the CTP151 chassis. For information about the CTP151 modules slot
numbering, see “CTP151 Modules Slot and Port Numbering” on page 57 .
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