Opto-Isolated RS232 to RS485 Converter (Industrial / Port-Powered)


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The CVT-485-3 is a compact, rugged, industrial-grade, optically-isolated, port-powered RS232 to RS485 converter, which can be used to convert any standard RS232C port into a 2-wire half-duplex RS485 port and vice versa. This industrial opto-isolated RS232 to RS485 converter supports multi-drop RS485 networks and can be used to communicate with one loop of up to 64 units of RS485 devices. It operates within temperature range of -40ºF to 185ºF (-40ºC to 85ºC), features 600W surge protection, 15kV static protection and 2500V opto-isolation circuitry, which effectively protect your RS-232 devices from ground loops, noise problems, transient surges, remote lightning, and spikes. The device is efficiently powered from the RS232 data line, and it supports data direction auto-turnaround, which automatically enables the RS485 transceiver when data is present on the RS232 side. Therefore, it requires no external power, software drivers or flow control. The ALL-IN-ONE rugged terminal block, which was professionally designed for different requirements such as selectable 120-Ohm terminator and optional 5V DC input, makes the unit an ideal solution for all types of installations.

CommFront's products quality is ensured by our ISO-9001 quality control system (Cert No. SG12/04213, strictly certified by SGS), and we back our high-quality products with a 5-year replacement warranty and a 30-day risk-free money-back guarantee.


  • Rugged industrial-grade port-powered opto-isolated RS232 to RS485 converter.
  • Converts RS232 to 2-wire RS485 and vice versa.
  • Port-powered, no external power or RTS, DTR required.
  • Industrial grade enclosed in a rugged, rustless ABS housing.
  • 2500V optical isolation.
  • Supports multi-drop RS485 networks (up to 64 nodes).
  • 1.2K to 57.6K Baud operation (auto-sensing & self-adjusting).
  • Operating temperature: -40ºF to 185ºF (-40ºC to 85ºC).
  • Accepts external 5V DC regulated power if the port-power is insufficient.
  • Plug and play (hot-pluggable, data format auto-sensing & self-adjusting).
  • Data direction auto-turnaround, no software drivers or flow control is required.
  • Built-in selectable 120Ω terminator for system reliability and easy installation.
  • Built-in 600W surge protection, 15kV static protection and circuit protection.
  • ALL-IN-ONE rugged terminal block designed for different requirements.
  • Surface Mount Technology manufactured to RoHS and ISO-9001 standards.
  • Safety: Strictly certified by TUV (Cert No. SG-CE-090012).
  • 5-year manufacturer's warranty.


Part Number: CVT-485-3
Compatibility:  EIA/TIA RS-232C standard and RS-485 standard
Power Source: Port power from RS232 data line
Current Consumption: Less than 10mA
Optical Isolation: 2500Vrms (AC, 1 min)
Baud Rates: 1,200 to 57,600bps (auto-sensing & self-adjusting)
Distance: RS-232 side: 16 ft (5m); RS-485 side: Depending on power from RS232 port, will transmit up to 4000 ft (1.2km) at 19,200bps
Connector: RS232 Side: DB-9 Female; RS485 Side: DB-9 Male; Termination Board: DB-9 Female and a 4-Way Terminal Block
Maximum number of drops: 64
End of Line Terminator: 120Ω (built-in, selectable)
Surge protection: 600W
Static protection (ESD): Up to 15KV
Dimensions (H x W x D): 0.6 x 1.3 x 3.5 in (16 x 32 x 88 mm)
Weight: 1.36 oz (39 g)
Operating Temperature: -40ºF to 185ºF (-40ºC to 85ºC)
Operating Humidity: Up to 90% RH (no condensation)





CommFront products are strictly certified by SGS and/or TUV - the Nationally Recognized Testing Laboratories [NRTLs] in North America (approved by OSHA) and the Notified Bodies in the European Union. Learn More




CommFront products are designed and manufactured to ISO 9001 standards. Our quality control system is strictly certified by SGS (Cert No. SG12/04213). Learn More




CommFront products have been proven to be reliable. We back our high-quality products with a 5-year replacement warranty and a 30-day risk-free money-back guarantee. Learn More

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