RS-232 to RS-422/485 Converter

  • Isolated
  • ESD Protection – 8 kV Contact, 15 kV Air
  • Rugged Metal Case
  • Wide Operating Temperature Models
  • Panel Mount with Available DIN Rail Adapters
  • Built in Switchable Bias & Termination


The SCP series RS-232 to RS-422/485 serial converters are compact and tough. Each model is designed and tested to meet heavy industrial EMC standards. The RS-232 signal is connected through a female DB9 connector. The RS-422/485 (2-Wire and 4-Wire) signal is connected through a removable terminal block, making wiring easy. Power is connected through a two position removable terminal block. Bit-wise enabled circuitry automatically detects the character time-out eliminating the need to set DIP switches for the baud rate. Model BB-SCP311T-DFTB3 offers 2 kV Isolation and will stand up to -40 to 80° C temperature variations. This is our most rugged model in this series. The BB-SCP311 is an excellent investment for protecting your expensive control equipment.

Part Number RS-232 Connector
BB-SCP311T-DFTB3 Wide-Temp, Isolated, RS-232 to 422/485 Converter
Serial Technology
RS-232 TD, RN, GND
RS-422/485 4W TDA(-), RDA(-), TDB(+), RDB(+), GND
RS-485 2W DATA A(-), DATA B(+), GND
Data Rate Up to 460.8 Kbps
Isolation 2 kV (SCP311T-DFTB3)
Surge Protection +/- 0.5 kV DC Ports, +/- 1 kV Signal Ports
Industrial Bus Modbus ASCII/RTU
Bias 1 KΩ Switchable
Termination 120 Ω Switchable
Connectors RS-232 – DB9F (DCE)
RS-422/485 – Removable Terminal Block
Source External
Power Connector Terminal Blocks
Input Voltage 10 to 30 VDC
Power Consumption 1.0 Watt Maximum
TD / RD Green LED (Also used to indicate power)
Dimensions 99x22.9x73.7 mm (3.9x0.9 x2.9 in)
Enclosure IP 30, Metal
Weight 0.33 lbs, 0.15 kg
MBTF 217576 Hours
MTBF Calc. Method MIL 217F Parts Count Reliability
Operating Temperature -40 to 80°C
Storage Temperature -40 to 85°C
Operating Humidity 0 to 95% Non-condensing
Approvals / Certifications
Regulatory UL Listed, UL File Number: E222870
Emissions FCC Class B, CISPR Class B (EN55022)
CE EN61000-6-2:2005 (Heavy Industrial)
EN61000-4-2:2008 (ESD) 8kV contact, 15kV air
EN61000-4-3:2006 (RI) 10 V/m
EN61000-4-4:2004 (EFT Burst) 1kV signal, 2kV power
EN61000-4-5:2005 (Surge) 1kV signal, 500V DC, 1kV AC
EN61000-4-6:2005 (CI) 10 Vrms

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