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Multi-Mode RS232 / RS485 / RS422 to Fiber Optic Converter

Model: SER-FIBER-MM - $135.95

Category: Fiber Optic Media Converters



Multi-mode ST Serial to Fiber Optic Converter

Multi-Mode (MM) RS232 / RS485 / RS422 to Fiber Optic Converter - ST Connector

Multi-mode SC Serial to Fiber Optic Converter

Multi-Mode (MM) RS232 / RS485 / RS422 to Fiber Optic Converter - SC Connector



30 Day Money Back Guarantee!
5 Year Replacement Warranty!



ST Type


The SER-FIBER-MM is an industrial grade bi-directional externally powered multi-functional RS232/RS485/RS422 to Multi-Mode Fiber Optic Converter which converts either full-duplex RS232, half-duplex RS485 or full-duplex RS422 to a Multi-mode SC or ST connector type fiber optic link. A data direction auto-turnaround feature automatically enables the serial transmit and receive data signals when data is present, avoiding the need for software drivers, and making the device fully plug-and-play. The SER-FIBER-MM has a 8 position terminal block for the serial port, and either an ST type or SC type connector for the fiber optic link. The unit extends the maximum distance of any RS232/RS485/RS422 signal up 1.2 miles (2.0 km) using MM fiber optic cable. The unit is enclosed in a rugged steel housing. An external power supply is included.  This converter operates from 300 to 460K bps.


  • Plug-and-Play (Hot-pluggable)
  • Externally Powered DC or Included AC Adapter
  • Fiber Optic Range of Up to 1.2 miles (2.0 KM)
  • Available with ST or SC Type Connectors
  • Free Optional DIN Rail Mounts
  • RS-232/RS-485/RS-422 Can Be Mixed or Matched
  • Data Direction Auto-turnaround - No Flow Control Necessary
  • Built-in 600W Surge and 15KV Static Protection
  • 5 Year Manufacturer's Warranty
  • RoHS, CE, and FCC Certified



Our internationally recognized ISO 9001:2015 Quality Management System (Cert. No. 743003912) with a scope of “Design, Sales and Distribution of Data Communication Products” was recognized and certified by TÜV Rheinland of North America known for its very demanding and stringent requirements. For more details see our Quality Policy.


We are a full service company offering the highest quality converters at a low price.



Quality Guarantee - SerialComm converters are low priced, high quality products and made to last a lifetime. They are manufactured in a ISO-9001 certified facility using surface mount technology with lead free components.  All converters are pretested prior to shipment and are fully guaranteed for 5 years.  There are no converters, Commercial or Industrial that surpass SerialComm's quality standards at any price tag. Satisfaction Guarantee - We offer a 100% 30 Day Money Back Guarantee which most companies do not offer.  If for any reason, you 're not satisfied with your purchase within 30 days, you can return it with no penalties.  We will return the full value of the order minus shipping costs. We do not reimburse express shipping fees.  We do not add restocking fees when returning a purchase within 30 days. Manufacturer's WarrantySerialComm offers a 5-year Workmanship Warranty.  We are so confident our product are built to last, within a 5 year period from the time of purchase, if a rare event of a malfunction should occur; we will replace your product for free.  Fill out our RMA form and we will issue you a RMA number for return of your product.   We do not issue refunds after 30 days of purchase. Express Shipping Guarantee - We specialize in shipping express orders on-time.  If FEDEX express shipping is selected before 6:30 PM E.S.T. and the items are in stock; we guarantee that we will get the order delivered to FEDEX on-time for the scheduled express delivery.  If we fail do to so, we will ship you the package the next day and credit you the full value of the order. (LIMITED TO $100 PER ORDER).  Please refer to our Terms for full details.

Free Worldwide Shipping - We offer FREE shipping with all SerialComm products with TRACKING!  Not just to the U.S., we ship our products worldwide for FREE.   Given availability of items, they are shipped the next business day with an ETA of 2-5 days for domestic and 5-15 days for International orders using USPS, FEDEX or DHL couriers.  Express Shipping is extra and shipped the same day ordered.


Sales & Technical Support -We offer sales and technical support by phone, live chat and email 24/7.  Our sales team  provides immediate customer support such as taking orders or assisting in expedited shipping requirements.  If you need technical help, an experienced Electrical Engineer can offer assistance.  Our technical support team can be an invaluable service which we provide for free.


Purchase Orders - We accept purchase orders as well as credit cards and PayPal. We understand that many companies prefer to issue purchase orders rather than using credit cards.  We accept purchase orders with NET 30 terms in most cases.    Not too many companies on the internet are willing to accept purchase orders but we do.  Purchase orders can be faxed or emailed.


Fully Certified - Certifying Data Communication Products is extremely important for compatibility, safety and standards compliance.  All of our products are fully certified and passed CE, FCC and RoHS compliance tests.  These certificates provide confidence that our products are the highest quality while also environmentally safe and compatible with other devices.