T1/E1 & C37.94 Fiber Service Units

  • T1/E1 and C37.94 thumb
T1/E1 and C37.94

Product Description

Fiber Service Units – T1/E1 and C37.94

RFL offers two types Fiber Service Units (FSU) for substation or industrial applications, this includes one for protective re-laying that complies to the IEEE C37.94 standard and another for T1/E1 applications. The C37.94 units offer a multitude of electrical interfaces for diverse applications (X.21, V.35, RS-449, G.703 and E1) and are also available with non-standard single mode fiber options. The T1/E1 units can be used with multi-mode and single mode fiber over varying distances and are also compatible with the optics on IMUX 2000 multiplexers. Both standard units are designed for wall mounting, however, rack mount options are available for both FSU’s with 1RU (1.75") and 3RU (5.25") 19" rack mount chassis.

T1/E1 FSU

Low Cost Fiber

  • Low cost fiber solution for T1/E1 fiber extension or point-to-point long haul applications. Ability to add fiber connectivity to other manufacturer's multiplexers.

Multiple Fiber Interfaces

  • The RFL T1/E1 FSU can be configured with 1300nm multimode or singlemode LED emitters or 1300nm and 1550nm LASER singlemode emitters.

Long Transmission Distances

  • Depending on the fiber emitters used, T1 or E1 signals can be transmitted up to a maximum of 90 km (55.9 miles) based on typical loss calculations. All fiber options feature automatic gain adjust so the receiver cannot be saturated, meaning no attenuators are required.

Wide Range Supply

  • Wide Range 38-150 VDC Power Supply

Rack-Mountable

  • Available for wall, 1RU x 19", or 3RU x 19" mount

C37.94 FSU

Low Cost Solution

  • Low cost solution to interface compliant Teleprotection equipment to existing non-compliant digital communication equipment

Multiple Electrical Interfaces

  • The RFL unit converts the optical signal into an electrical signal that will be accepted by the multiplexer. It is available with RS449, G.703, V.35, X.21 and E1 interfaces.

Multiple Transmission Speeds

  • The data is typically 64kb/s but the standard provides for speeds up to 768kb/s or (12 x 64 kb/s). The gross bit rate is 2.048 Mb/x and the frame complies with G.704 (E1) rules.

Wide Range Supply

  • Wide Range 38-150 VDC Power Supply

Rack-Mountable

  • Available for wall, 1RU x 19", or 3RU x 19" mount

T1/E1 FSU

Electrical and Enviromental

Operating Temperature: -20 C to +55 C
Operating Humidity: 90% RH Non-Condensing @ 40 C
Supply Voltage: 38 to 150 Vdc
Power Consumption: Less than 5W
ESD Withstand: ANSI C.37.90.3
RFI Withstand: ANSI C.37.90.2
SWC Withstand: ANSI C.37.90.1
Dielectric Withstand: 2500 VDC (Power and Alarm Inputs)

Regulatory Requirements

MTBF: Bellcore TR332 Issue 5, Method 1
>1,000,000 Hours
Case 3, Temp = 25 C

Alarms

Alarm Relay Output: Form "C" (SPDT)
Alarm Relay Open Circuit Voltage: 300 VDC
Alarm Relay Current (Continuous): 1 Amp
Alarm Relay Breaking Current: 1 Amp, Non- inductive

T1 Interface

Electrical Specification: ANSI T1.104
Frame Format: ANSI T1.104
Line Coding: AMI/B8ZS (Jumper/Switch selectable)
Signaling: Transparent to product
Interface Impedance: 120 Ohm Twisted pair
Connector: D-Subminiature 15 position male connector
Multiframe Format: ESF or SF

E1 Interface

Electrical Specification: ITU G.703
Frame Format: ITU G.704
Line Coding: AMI/HDB3 (Jumper/Switch selectable)
Interface Impedance: 120 Ohm Twisted Pair or
75 Ohm Coax (selectable)
Connector: D-Subminiature 15 position male connector
and 2 BNC coax connectors.

Dimensions:

Width: 5.13 inches (13 cm)
Height: 1.77 inches (4.5 cm)
Depth: 8.51 inches (21.6 cm)

C37.94 FSU

IEEE Standard:

C37.94 for N times 64 kilobit per second optical fiber interfaces between Teleprotection and multiplexer equipment.

Electrical and Enviromental

Operating Temperature: -30 C to +60 C
Operating Humidity: 95% RH Non-Condensing @ 40C
Supply Voltage: 38 to 150 Vdc
Power Consumption: Less than 5W
ESD Withstand: ANSI C.37.90.3
RFI Withstand: ANSI C.37.90.2
SWC Withstand: ANSI C.37.90.1
Dielectric Withstand: C37.90

Regulatory Requirements

MTBF: Bellcore TR332 Issue 5, Method 1
>1,000,000 Hours
Case 3, Temp = 25 C
Wavelength and Emitter Type: 820/850nm LED (Short Haul)
Fiber Type: 50 or 62.5 Micron Multimode
Optical Budget: 62.5
Micron Core: 13db
Digital Connectors: 15-pin male type D subminiature for G.703 and X.21
37-pin male type D subminiature for RS-449 and V.35
15-pin male type D subminiature or dual BNCs for E1
Optical Connector Type: ST

Dimensions:

Width: 5.13 inches (13 cm)
Height: 1.77 inches (4.5 cm)
Depth: 8.51 inches (21.6 cm)

850 nm Short Haul Fiber Interface

The RFL 9745 is typically located close to the protective relaying equipment. The communications equipment could be located in a different room or building in the substation. The RFL 9745 when configured with the Short Haul Fiber Interface eliminates the ground potential rise and induced voltage concerns associated with routing a copper communications cable between two sites. A pair of 850 nm multimode fiber optic cables are routed between the two locations. The fibers can be up to 1 kilometer (3,280 feet) long and terminated with ST type connectors.

There are two ways to implement short haul fiber communications between the RFL 9745 and a multiplexer. The Short Haul Fiber Interface for the RFL 9745 is compliant to the ANSI C37.94 Short Haul Fiber Standard and will directly communicate to a multiplexer with a compliant interface. If the multiplexer does not support the standard, RFL can provide a remote Fiber Optic Service Unit that converts the optical signal into an electrical signal that will be accepted by the multiplexer.

The digital output of the Fiber Optic Service Unit is connected to the communications equipment by a short electrical cable as shown in Figure 1. If the communications equipment supports the ANSI 37.94 Short Haul Fiber Interface standard the fiber optic cables can be interfaced directly to it as shown in Figure 2.

Short Haul Fiber Interface

Ordering Information

Product information chart

    * The stated "Typical Distances" are based on the following assumptions:
  • 0.05 db splice loss every 2Km
  • 2 db Connector loss for ST connector (total both ends)
  • 1 db/Km loss for 1300 nm Multimode fiber
  • 0.5 db/Km loss for 1300 nm Singlemode fiber
  • 0.25 db/Km loss for 1550 nm Singlemode fiber
FSU Part Numbers

Available Files

Files Available in the Customer Area

Please visit Operating Manuals or Product/Software Downloads to download relevant files. Requires RFL Customer Account.

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