going obsolete

Point System™ RS422/485 Media Converter Module
RS422/485 Copper to Fiber

CRS4F Series



The CRS4F Series chassis card serial RS422/485 to fiber media converter allows you to extend the distance between serial connections with the use of fiber optic cable. This full-featured converter operates in 2-wire mode for RS422 and either 2-wire or 4-wire mode for RS485 and supports full or half-duplex data transmission at speeds up to 1.25 Mbps.

View Going Obsolete Notification Here


  • RS422 or RS485 operation
  • 2-wire or 4-wire in operation in RS-485 mode
  • Full/Half-duplex transmission at speeds up to 1.25 Mbps
  • Field Upgradeable Firmware
  • Can be used with any Point System™ Chassis


Management Features

  • Report Converter status to Chassis management software:
    • Local Fiber Link status
    • Receive data activity on the copper link
    • Local Switch settings
    • 130 ohm resistor on RX
    • 130 ohm resistor on TX
    • 1K ohm “pull down”
    • 1K ohm “pull up”
    • 2-wire/4-wire operation
    • RS-485/RS-422 operation


Standards EIA/TIA RS-422
Switch SW1: 130 ohm resistor Rx (Down = enable)
SW2: 130 ohm resistor Tx (Down = enable)
SW3: 1k ohm “pull-down” (Down = enable)
SW4: 1k ohm “pull-up” (Down = enable)
SW5: 2-wire/4-wire (Down = 4-wire)
SW6: RS-485/RS-422 (Down = RS-422)
Status LEDs PWR (Power): Lit for normal operation
RXC: Steady = Data Rx on copper link;
Flashing = Rx Data at low speed
RXF: Steady = Fiber Link
Dimensions Width: 0.86” [22 mm]
Depth: 5" [127 mm]
Height: 3.4” [86 mm]
Power Consumption 5.0 Watts
Environment Environment specs are dependent on the chassis chosen
Operating: 0°C to 50°C
Humidity: 5% to 95% (non-condensing)
Altitude: 0 – 10,000 ft.
Weight 1 lb. [0.45 kg]
Compliance CISPR22/EN55022, EN55024, EN60950 Class A,
FCC Class A, CE Mark, UL 1950
Warranty Lifetime

Ordering Information

SKU Description  

Terminal Block [1.2 km/0.7 mi.]
to 1300nm multimode (ST) [2 km/1.2 mi.]
Link Budget: 11.0 dB

Add to Quote

Terminal Block [1.2 km/0.7 mi.]
to 1300nm multimode (SC) [2 km/1.2 mi.]
Link Budget: 11.0 dB

Add to Quote

Terminal Block [1.2 km/0.7 mi.]
to 1310nm single mode (SC) [20 km/12.4 mi.]
Link Budget: 16.0 dB

Add to Quote

*Product is in BTO status and is built on a per order basis. Please contact a Transition Networks sales associate for details and lead times.