External Timing Ports - Juniper ERX - RELEASE 11.1.X HARDWARE GUIDE 03-23-2010 Hardware Manual

ERX 11.1.x Hardware Guide
NOTE: The alarm function on the SRP I/O module is currently not implemented.
Only ERX7xx and ERX14xx models have external timing ports and alarm leads
located on the SRP I/O module. All ERX routers have console ports located on the
SRP I/O module. See Table 7 on page 50 for details on each component.
Table 7: SRP I/O Ports

External Timing Ports

NOTE: This section applies to ERX7xx and ERX14xx models only. The ERX310 router
does not support external timing.
The SRP I/O module has two input ports for external clock sources. These ports
provide a way to ensure that the router system clock remains synchronized with the
network's system clock. The primary clock is labeled A; the secondary, redundant
clock is labeled B.
Use the connectors appropriate for your locale (European or North American
standard):
NOTE: Use shielded cables to connect the external clock sources to the clock source
input ports.
50
Cabling the SRP I/O Module
Port
Alarm leads (ERX7xx and
ERX14xx models only)
External timing ports (ERX7xx
and ERX14xx models only)
Management console ports
European Two 75-ohm E1 2.048-Mbps inputs with BNC connectors
North American Two 100-ohm T1 inputs with three pin wire-wrap connectors.
Pins are labeled T (tip), G (ground), and R (ring). We recommend using 26-AWG
wire minimum.
Description
Six terminal blocks for external alarm contacts; use a
minimum 26-AWG for each (currently not implemented)
Two 3-pin wire-wrap posts for US external clock sources;
primary (A) and secondary (B)
Two BNC connectors for E1 clock sources; primary (A)
and secondary (B)
One 10/100Base-T Ethernet management port with an
RJ-45 connector
One RS-232 console port with a DB-9 connector for
VT100 management access