CRS Series 1:1 Modem Redundancy Switches

Comtech EF Data

CRS Series 1:1 Modem Redundancy Switches

Master Distributor

Contact Us For Pricing

  • Full bridging architecture, with configuration synchronization
  • TX Clock and Data signals fed to both online and standby units
  • RX IF signal fed to both online and standby units

SKU: CMT123 Tags: , ,
  • Description
  • Technical Specifications
  • Support Documents

Overview

Our 1:1 Modem Redundancy Switches purpose is to continuously monitor a pair of modems in a redundant configuration, so that the unit automatically switches data and IF signals from the primary unit to the standby unit if an equipment failure or undesired traffic condition occur. This fully protects traffic paths, and the operator can have increased confidence that equipment failures will not adversely affect system availability.

There are two types of 1:1 switches; active and passive. The CRS-150 is an active type, which provides a copy of the TX traffic data that is delivered to the offline modem so that both modems units see identical traffic signals. The CRS-170A and CRS-180 are both passive switches that perform IF switching, and the data is passively switched within the pair of modems interconnected by a Y-cable. The net result is the same: both modems see the identical TX and RX traffic signals permitting the continual comparison of fault status.

Details

  • Full bridging architecture, with configuration synchronization
  • TX Clock and Data signals fed to both online and standby units
  • RX IF signal fed to both online and standby units
  • Continuous fault comparison of online and standby units (The configuration of online and standby units is synchronized via the Auxiliary Serial link between the two Modems)

CRS-150 Specifications
Fault Detection Time (maximum) 1 second
Switchover Time (after fault detection) CRS-150: Within 0.5 seconds typical with RS-422
Main Data Interfaces RS-422/EIA-530 DCE (25-pin D-type female, per EIA-530) to 10 Mbps, V.35 DCE to 10 Mbps, synchronous RS-232 to 300 kbps, serial LVDS to 20 Mbps (A standard HSSI interface is provided with the addition of the Comtech EF Data CIC-20 LVDS/HSSI Interface Converter module, for operation up to 20 Mbps)
G.703 Interfaces G.703, T1, E1, T2 and E2, bal. and unbal. (BNC connectors for 75 Ω unbal., and
15-pin D-type for 120 Ω balanced) Note that for T1 and E1 Drop and Insert applications the unit supports RX, TX connections, Drop Data Out (DDO), and Insert Data In (IDI) ‘G.703-like’ signals at 512 kbps and 1024 kbps (through DDO and IDI ports)
Overhead Interface Intelsat IESS-308/-309/-310 Open Network overhead signals, including: IDR overhead data channels (64 kHz, 8 kHz, and Octet clocks), IBS ESC and high-rate ESC, balanced external reference input, IDR backward alarm inputs, (25-pin Dtype male)
IF Switching Transmit IF: Switched by RF relay (0.3 dB max. loss)
Receive IF: Passive power splitting (3.5 dB max. loss)
IF Impedance Optimized for 50 Ω (> 20 dB return loss on external IF ports) 75 Ω supported with the use of external RF transformers (supplied)
IF Connectors BNC female
IF Freq. Range 52 - 176 MHz
Dimensions (1RU) (height x width x depth) 1.75” x 19” x 4.2” (4.45 x 48.25 x 10.7 cm)
Weight 4.6 lbs (2.1 kg)
Power Requirements 4.5 W maximum
+ 12 volts DC @ 250 mA, -12 volts DC
@ 120 mA
Power is supplied by the online and standby Modems, and the unit current shares when both an >A= and >B= unit are present. These power supplies are electronically fused and protected. A pair of auxiliary DC inputs are provided for powering external equipment connected to main data interface, such as a CIC-20 Interface Converter.
Approval CE as follows: EN 55022 Class B (Emissions), EN 50082-1 (Immunity), EN 60950 (Safety) FCC Part 15 Class B
Fault Detection Time (maximum) 1 second
CRS-170A Specifications
Fault Detection Time (maximum) 0.5 seconds
Switchover Time (after fault detection) Within 0.1 seconds typical with RS-422 or HSSI
Main Data Interfaces Refer to the modems’ datasheets
IF Switching Transmit IF: Switched by RF relay (1.5 dB max. loss)
Receive IF: Passive power splitting (7.0 dB max. loss)
Dimensions (height x width x depth) 1.7” x 5.7” x 4.1” (4.3 x 14.3 x 10.4 cm)
Weight 1.1 lbs (0.5 kg)
Power Requirements +12 VDC @ 200 mA (max.)
Approval CE
CRS-180 Specifications
Fault Detection Time (maximum) 0.5 seconds
Switchover Time (after fault detection) Within 0.1 seconds typical with RS-422 or HSSI
Main Data Interfaces Refer to the modems’ datasheets
IF Switching Transmit IF: Switched by RF relay (1.5 dB max. loss)
Receive IF: Passive power splitting (4.0 dB max. loss)
Dimensions (height x width x depth) 1.7” x 5.7” x 4.1” (4.3 x 14.3 x 10.4 cm)
Weight 1.1 lbs (0.5 kg)
Power Requirements +12 VDC @ 80 mA (max.)
Approval CE
(View our PDF Datasheet for more information)

Quote Request - CRS Series 1:1 Modem Redundancy Switches


Name:

E-mail: *required

Phone:

Quantity:

Additional Products/Notes/Questions: