Chapter 5. Cables And Connections; Overview - Comtech EF Data CRS-170A Installation And Operation Manual

5.1

Overview

When assembling a Comtech EF Data 1:1 Redundancy System, in addition to purchasing the modem pair
(one Redundant Modem, one Traffic Modem), you must also purchase a redundancy kit tailored to that
modem choice. Each kit provides the CRS-170A L-Band 1:1 Redundancy Switch module, plus all cables
and components required for interconnection of the redundant configuration to various interfaces (i.e.,
control, IF, and data). This excludes Ethernet operation, which requires user-provided cabling and Layer
2 switching.
1) The cables required between each modem and Switch should be of shielded, twisted-
pair construction, with the grounded shield bonded to the back shell. All data cables
should be wired correctly using the pinout and connection information as specified in
Appendix A. CABLE DRAWINGS.
2) It is physically impossible to connect all available data interface solutions within a single
1:1 redundancy system at a given time. For example, when using the CDM-625A or
CDM-625 in a 1:1 system, you are unable to establish an ASI interface together with a
G.703 Unbalanced interface, or an EIA-422/232 interface together with an HSSI
interface. The quantities of cables and accessories supplied with each redundancy kit
take such operational limitation into consideration.
3) The type of 1:1 Y-Splitter cable required for modem-to-user interconnection depends on
your data interface. It is essential to ensure that the control and IF connections, both Rx
and Tx, are made correctly.
4) The Electronic Industries Association (EIA) designations supersede the Recommended
Standard (RS) designations. References to the old designations may be shown when
depicting actual text (e.g., RS-232) displayed on Switch or the individual modem Web
Server pages, serial remote interfaces, Telnet Command Line Interfaces (CLIs), or unit
rear panels. All other references in the manual refer to EIA designations.
5) The modem-specific sections in this chapter identify the required redundancy kit:
• Section 5.2 Common CRS-170A 1:1 Redundancy Control / IF Interface Cabling Kits
•
Section 5.3 Cabling the CDM-625A or CDM-625
•
Section 5.4 Cabling the Heights Remote Gateway
•
Section 5.5 Cabling the Advanced VSAT CDM-850
•
Section 5.6 Cabling the Advanced VSAT CDM-840
Chapter 5. CABLES
5–1
CONNECTIONS
AND