Front: FIMO-232 RS232 to Fibre Optic Modem
Rear: FIMO-232 RS232 to Fibre Optic Modem

RS232 to Singlemode Long Haul Fiber Optic Modem

Metrodata now offers an enhanced converter with features providing the benefits of supporting RS232 asynchronous data rates up to 256kbps and covering distances up to 70km (using singlemode long haul fibre).

RS232 to Singlemode Long Haul Fibre Modem

  • Asynchronous RS-232 up to 256kbps
  • Standard 9 way D-type RS-232 connector
  • DTE or DCE interface
  • Must be used in pairs
  • Data rate agile
  • Payload and protocol transparent
  • Minimal configuration of unit needed
  • Easy to install & maintain
  • Integral auto-sensing power supply (100-250V AC or -40V DC versions)
  • 12-24V DC power supply available on request
  • External alarm relay port
  • Compact modem style unit, built to European standards
  • Rack mounting kits for 2 or 18 units available
  • Alternate product for Probot 3008
  • FIMO-232 Fibre Optic Modem product range
Extending RS232 over fibre
FIMO-232 as an RS232 over multimode fibre converter

There are many RS232 interface devices such as terminals, printers, computers, video displays and ticketing machines that can be easily connected over the increasing use of Fibre links.

Often converters only offer 19.2kbps, 38.4kbps or up to 115.2kbps and operate as a DCE whereas the Metrodata FIMO-232 increases the asynchronous data rate up to the higher rate of 256kbps and has a cross over function supporting DCE to DTE, DCE to DCE and DTE to DTE configurations. The FIMO-232 is a standalone unit with one used at each end of the fibre link

There are three models in the range:

  • FIMO-232/MM: RS232 over multimode fibre up to 5km
  • FIMO-232/SMSH: RS232 over short haul singlemode fibre up to 30km
  • FIMO-232/SMLH: RS232 over long haul singlemode fibre up to 70km

The maximum operating distance of the FIMO-232 is up to 30km or 70km using singlemode fibre, although specific installations may only operate over lower distances due to the variations in losses of different types of fibre cable, the use of connecting fibre cables, or patch panels. When operating over 50% of the maximum distances it is advisable to calculate all fibre optic connector and cable losses and compare these with the fibre optic loss budget specified for this product.

All Metrodata fibre modems are supplied as standard with SC connectors operating at a nominal wavelength of 1300nm. Other wavelengths are available on request, e.g. 850nm, 1550nm, 1550/1300 WDM. Other connectors are also available on request, e.g. ST, FC.

The FIMO-232 can easily be rack mounted in either a 1U two unit rack mount kit, or in a 6U eighteen unit rack mount kit.

The FIMO-232 is part of a range of products from Metrodata, offering fibre conversion solutions ranging from 300 baud RS-232, via Nx64kbps rates, through 2Mbps and up to 155Mbps for electrical to fibre conversion; or 155Mbps, 622Mbps or Gigabit Ethernet for fibre mode or wavelength conversion.

Terminal extension over singlemode fibre
FIMO-232/SMLH: RS232 extension over long haul singlemode fibre

This application shows a terminal session being extended over a long haul singlemode fibre using a pair of FIMO-232/SMLH units. This singlemode fibre could be across a city, or between cities (e.g. over a rented fibre).

RS-232 Electrical Interface
Presentation 9 way D-type, Male DTE or Female DCE
Maximum data rate 256Kbps
Singlemode Long Haul Fiber Interface
Interface Dual SC singlemode 8/125um
Wavelength 1300nm
Bit Rate 155 Mbps +/- 15ppm
Tx Power 0 to -5 dBm
Max Rx Power -8 dBm (may need an attenuator)
Rx Sensitivity -8 to -34 dBm
Optical loss budget -5 - (-34) = 29 dB
Compliance & Approvals
Safety EN60950
Temperature 0-50 deg C
Humidity0-95% RH, non condensing
Pressure 86-106 kPa
Power Supply Options
-48 VDC -40 to -72 DC, 200-100 mA
AC Mains 100-250 VAC, 50-400Hz, 60-25mA IEC connector
Power Consumption 6 watts approx when operating
Type Modem, 1U high without feet, IP30C
Dimensions W x D x H (mm)
Rack mount 202 x 132 x 44 (without feet)
Tabletop 202 x 132 x 48 (with feet)
Part Number
Product AC Mains DC Power
FIMO-232/SMLH 80-05-926
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2 Unit Rack mount Kit80-05-256
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18 Unit Rack mount Kit80-05-250
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Product variants with 12V to 24V DC operation are also available on request.

Product Downloads


Further Information

Related Products

Serial Converters
Fibre Converters
  • E1/T1 G703 BNC/RJ45 equipment, e.g. routers or PBXs - FC1X00
  • Multimode Fibre interfaces at 155Mbit/s, e.g. routers - FC2X00: MM to SM SH/LH Fibre Mode Converter (100baseF, 155Mbps)
  • E3/DS3 G.703 equipment, e.g. routers or broadcast video equipment - FC3X00
  • STM-1/OC-3 BNC G703 equipment, e.g. core switches - FC4X00
  • Multimode Fibre interfaces at 622Mbit/s, e.g. routers - FC6X00
  • RS232, e.g. terminals - FIMO-232
  • V.35, V.36, X.21, e.g. routers or video conferencing equipment - FIMO2100
  • 1000BaseSX to 1000BaseLX Gigabit Ethernet Converter - FC-GigE
  • Simple method of delivering 4, 8 or 16 E1 services over redundant fibre - EMUX
  • Multiple Ethernet, E1 and T1 equipment - MetroLAN1000
  • Multiple Ethernet, E1, T1, E3 and DS3 equipment - MetroLAN2000

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