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F232C: Duplex Multimode Fiber to RS232C Full Duplex Serial Converter


F232C in Box

F232C Label

"Let me spin a very large
RS485 network for you!"


Product Features

  • This unit features full duplex serial conversion from RS232C to a pair of ST 62.5 micron multimode ports.

  • Designed for use in environments not requiring the internal opto isolation, yet maintaining the high isolation features of fiber cable.

  • A pair of these units will allow an extented distance connection, 1Km minimum, typically 1mile, with extreme isolation, between two RS232C devices.

  • The inherent noise immunity of the fiber cable allows reliable communications in environments that are hostile to other methods.

  • Transparent to all asynchronous data, with any combination of data, parity, and stop bits, at data rates up to 115.2Kbps. Faster speeds are available, in this, and our other products. No Jumpers or settings ordinarily required.

  • Jumpers J1-J4 allow the RS232C port to be configured as DTE or DCE.

  • Jumpers J6 and J7 can be used to optimize performance under certain speed and fiber cable conditions.

  • The control signals CTS, RTS, and DSR are provided to be used as required by the user set up. These signals are not required, nor used in any way, by this converter.

  • Edge mounted LEDs display power and data activity at the fiber interface.

  • Broad environmental range. -40C to +80C ambient, 10 to 90% RH(non-condensing)

  • Four(4) easy mount through hole standoffs, which accept #6 hardware, are provided on the circuit board.

  • User connections are the two fiber ports, an RJ11/12 jack for the RS232C port, and a terminal strip and barrel connector for the input power.

  • Accessories available are an enclosure, a wall wart power supply, fiber cables, RJ11/12 to DB9(M or F) adapter cable, and conformal coating. Contact us for options help.

  • R E Smith Inc makes a wide variety of isolated converters that address the electrical noise problems that contribute to unreliable communications, and product failure. If what you see here is not exactly what you need, don't hesitate in calling us at 513-874-4796.

  • We also have a new series of Converters and Repeaters that extend the RS232C communications distance far beyond conventional limits. Contact us for information on these leading edge problem solvers.

  • WARNING: Do NOT connect this device to a telephone system under any circumstances. Damage could result to the circuit board and/or your telephone system.

About R E Smith, Inc:

R E Smith, Inc. engineers and manufactures a comprehensive line of isolated and non-isolated converters, repeaters, multiport repeater hubs, fiber optic based products, and I/O boards. All our products are designed, built, tested, and shipped from our facility in the Greater Cincinnati Ohio area. We ship small quantities of most products from stock the same day, and larger quantities in a few business days.

We listen to you. We are customer driven. Many of our products were developed and improved due to suggestions and feedback from our word-wide customer base. They are being used at the South Pole, at the bottom of the sea, at the edge of space, and everywhere in between. Typical uses are very large networks, monitor and control of elevators, machinery, lighting, security, fire and alarm, access, cameras, military ground support, and much more. We provide free technical support, no-argument warranty repairs, and recommendations for your application. Challenge us with your communications problem. We may already have the solution. If your system keeps failing, or is unreliable, we have isolated, doubly isolated, noise resistant, cost effective, and proven solutions for difficult environments.

Related Files:

pdf icon F232CrevD.pdf Converter schematic/physical Rev. D

Physical Properties and Features:

Fiber: Two ST Connectors
RS232C: RJ11/12 Telephone style jack
Power: Barrel and 2 pin screw terminal strip.
LEDs RS485: Power(Yellow), data activity(TX: red, RX: green)
Fiber: Power(Yellow), data activity(TX: red, RX: green)
Aux control: 2.2K Ohm pull-up outputs for CTS, RTS, and DSR control


Distance: Fiber: 1Km Min, RS232C: Consistant with the RS232C distance/speed specification
Operation: Fiber to full duplex RS232C
Format: Asynchronous data with any combination of bits, parity, and stop (auto mode)
Speed: Up to 115.2Kbps
Environmental: -40C to +80C ambient, 10-90% RH(non-condensing)
Supply Voltage: 9-35 VDC
Power: Under 1/2 Watt(typical) + external load
Size: 3.50" X 2.75" X 0.9" (PC Board), with connectors: 3.50" X 3.50"
Mounting: 4 Holes at 2.25" X 3.00" (built-in standoffs for #6 hardware)

Options and Ordering Information:

F232C: $175.00 ea. (Circuit board only)
Enclosure: $10.00 ea. (medium)
Cable: $7.50 (7ft RJ11/12, telephone style, to DB9M or DB9F)
Power Adapter: $8.50 ea (wall wart type which meets most
California, and most world wide safety and efficiency standards)

This is the complete order number for the F232C with all options, except fiber cables:

F232C with options (Power Supply, RS232C cable, and enclosure): Order Number: F232C-B9FSPS @ $201.00 ea. (Qty. 1-9)

Need a different configuration or more information? Give Ron a Call at 513-874-4796 or 513-638-0228(Cell)


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