CTP151 Multiservice Interface Module

The Juniper Networks CTP151 Circuit to Packet platform optionally includes a Serial Multiservice Interface module CTP150-IM-SER-MS. The module provides 4-KHz or high-quality analog audio, or interrange instrumentation group (IRIG) signals.

The multiservice card enables an IRIG time code (IRIG-B) signal to be transported through an IP network. The IRIG-B standard consists of a family of rate-scaled serial time codes with formats containing up to three coded expressions or words. The IRIG-B pulse code contains one frame of 100 elements per second for the time of the year and GPS receiver status. IRIG-B encodes day of year, hour, minute, and second data on a 1-KHz carrier frequency, with an update rate of once per second.

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 1). The lowest-numbered port (marked 0) is at the bottom left, and the highest-numbered port (marked 3) is at the top right.

Figure 1: CTP151 Serial Multiservice Interface Module

1 — Four small serial ports and one clock reference port

2 — STATUS LED

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.