Industrial RS-232/422/485 To Dual Fiber Ports Converter, Multi-Mode 2km, with ST Connector. 2.5KV Isolation. EOT: -40° ~ 75°C

The Antaira STF-500C Series are Industrial Grade Design Serial-to-Fiber Media Converters that provide rugged solution to extend asynchronous RS-232, or RS-422/485 serial data transmissions over a distance of up to 2Km in Multimode fiber, or up to 30Km in Single mode fiber.

The converter is capable of selecting interface modes for connection to RS-232 (3 or 5 wire), RS-485 (2 or 4 wire, half or full duplex) or RS-422 (4 wire, full duplex). With the High Performance design, the STF-500C series provide:

High Data Protection:

  • Secures Asynchronous Serial Data transmissions over EMI resistant fiber at speeds up to 1024Kbps
  • Built-in RS-485 auto detection feature, 8KV ESD Protection and 2.5KV Isolation for Serial data transmission protection; and 10 positions Rotary Switch for RS-422/485 Pull high/low feature.


Secure Serial Network:


  • Supports Point-to-Point, Daisy Chain, and Half Duplex Ring Topology Fiber Network
  • STF-502C series supports Point-to-Point, Single Duplex Fiber connection (without Protection), or Dual Duplex Fiber connection (with Fiber Protection) - Redundancy Serial Fiber Network with Dual Fiber connections


Easy Monitoring and Maintenance:


  • Built-in Dual alarm relay contacts and Dual redundant DC power inputs
  • Front LED indicators for any Power, TD/RD, or Fiber Link failure monitoring


The STF-500C Series is a high performance & protection solutions for critical applications, such as


  • High Serial Isolation Protection for Outdoor Equipment data extension in ITS Signaling, or VMS;
  • Dual Fiber Ring Redundancy Serial Network in Firm Alarm Panels control;
  • EMI resistant for IEDs data transmission in Substation Automation;
  • Industrial Control in Process Control Automation, such as WWTP and Oil/Gas/Mining.
  • Supports Point-to-Point, Daisy Chain or Ring Connection
  • Supports RS-232, RS422/485 (2/4 Wire) Transmission to Single or Dual Fiber Connections
  • Enhanced Serial Baud Rate up to 1024Kbps
  • Supports ST Multi-Mode in 2Km
  • 2.5KV Isolation Protection for Serial Signal
  • Supports Relay Output for Power or Link Failure Warning
  • 10 Position Rotary Switch for RS-422/485 Pull High/Low Transmission
  • Hardened housing with IP30 protection
  • Fan-less and Din-Rail design for harsh industrial environment
  • Redundant Dual Power Inputs (12 ~ 48VDC)
  • Operating Temperature Range: -40~75°C
  • 5-Year Warranty
Package Content
  • Quick Installation Guide
  • CD Manual/Software
  • Wall Mounting Kit
Optional Accessories
  • NDR-75-24
    75W Single Output Industrial Din-rail, 24VDC Output
Related Resources
Baud Rate
  • 50 up to 1024Kbps (RS-422/485)
  • 230.4Kbps (RS-232-CH1)
  • 115.2Kbps (RS-232-CH2)
Serial Signals
  • RS-232 - CH1 TD/RD, CH2 TD/RD, GND
  • RS-422-4w - TxD+, TxD-, RxD+, RxD-, GND
  • RS-485-2w - Data+, Data-,GND
Pull High/Low
Adjustment by 10 position rotary switch
Fiber Interface
Fiber Port Count
2 ports
100 BASE-FX Fiber
2 ports (ST connector)
Transmission Distance
2 km
Tx Power
-14 ~ -20 dBm
Rx Sensitivity
-31 dBm
Serial Interface
Serial Port Count
1 port
Serial Interface
Other Interface
DIP Switch
6 PIN Mode Switch
LED Indicator
Alarm,PWR1,PWR2,TD/RD,Master,Ring, Fiber1,Fiber 2
Transfer Rate
50 up to 1024Kbps (RS-422/485)230.4Kbps (RS-232-CH1)115.2Kbps (RS-232-CH2)
Power Requirements
Power Connection
7-pin removal terminal block
Input Voltage
12V, 24V, 48V DC (9.6V–58V DC absolute)
Power Redundancy
Relay Output
24V DC, 1A resistive
System Power Consumption
5 Watts
Reverse Polarity Protection
Isolation Protection
Environmental Limits
Operating Temperature
-40° to 75° C (-40° to 167° F)
Storage Temperature
-40° to 85° C (-40° to 185° F)
Ambient Relative Humidity
5% to 95% non-condensing
Mechanical Characteristics
Metal, IP30 Protection
DIN-Rail mount, Wall mount (Optional)
Dimensions (W × H × D)
106 × 39 × 142 mm ( 4.72 × 1.54 × 5.59 inches)
1.59 lbs (0.72 kg)
Regulatory Approvals
FCC Part15, CISPR (EN55022) Class A
  • IEC 61000-4-2:2008 ESD (Level 3)
  • IEC 61000-4-3:2006+A1:2007+A2:2010 RS (Level 3)
  • IEC 61000-4-4:2012 EFT (Level 3)
  • IEC 61000-4-5:2005 SURGE (Level 3)
  • IEC 61000-4-6:2008 CS (Level 3)
  • IEC 61000-4-8:2009 PFMF (Level 3)
  • IEC 61000-4-11:2004 DIPS (Level 3)
Stability Testing
  • Shock: IEC60068-2-27
  • Free Fall: IEC60068-2-32
  • Vibration: IEC60068-2-6
797,101 hours
RoHS Compliant
5 years