TRP-C51B     Bluetooth to RS-232/422/485 Converter


The TRP-C51B is high stability device that is able to re-connect when the external power fail in paired mode, it provides a simple and friendly interface that allows user easy to configure the serial data format.

Based on the 2.4g automatic frequency hopping technology, It is widely used in parking towers, industrial automation, moving rail cars and.. etc.

 TRP-C51B can operate in direct link mode and paired mode, when in paired mode, the user just need to power two devices, and they will automatically connect.

What is different between TRP-C51A and TRP-C51B


  • Bluetooth V1.2 Class 1 compliance. (2.5mW/4dBm)
  • Transmission range open filed over to 100M.
  • Auto reconnect when the external power lost. 
  • Auto clear serial buffer when the data continuity input when re-boot. 
  • Auto directionally RS485 signal communication.
  • Direct Mode supports Modbus RTU/ASCII slave device.
  • Option to 1KM when replace the direction antenna.
  • Support all common baud rate from 1.2K to 256Kbps.
  • Friendly interface TRP-BT configuration windows utility
  • RS422 and RS485 signal auto switching.
  • LED indicators for Power/Link/TX/RX.
  • Surge protection on RS422/RS485.
  • Power supply: Screw terminal, or external DC adapter.
  • Wide input range power supply.
  • DIN rail and panel mount support.


  • Power requirement: DC voltage input from +10V to +30V.
  • RS232 signal: TXD, RXD, GND, RTS, CTS.
  • RS422/485 connection: industrial plug-in screw terminal.
  • RS485 signal: differential 2 half-duplex wires. (D+, D-)
  • RS422 signal: differential 4 full-duplex wires.(TX+, TX-, RX+, RX-)
  • Baud rate: 1.2Kbps to 256Kbps.
  • Data bit: 8
  • Support Parity check: None, Even, Odd.
  • Stop bit: 1, 2.
  • RS232 flow control RTS/CTS: Enable, Disable.
  • Host PC com port to TRP-C51 connection: use null modem female-female cable.
  • Plug-in screw terminal wiring: Accepts AWG #12 ~30 wires.
  • Wireless transmission distance: Open filed: 100M.
  • Antenna cable length:1530mm.
  • RS422/485 distance: up to 4000ft. (1200M)
  • LED indicator: Power, Link, TX, and RX.
  • Power input type: Screw terminal or DC plug.(5.5*2.1*12mm/500mA)
  • Power consumption: 1.2 watt. 
  • Operating temperature: -10 to 50℃.
  • Storage temperature: -20 to 65℃.
  • Humidity: 10-90% Non-condensing.
  • Dimension: 151mm X 75mm X 26mm.
  • Weight:  400g.



Directional outdoor antenna for TRP-C51 (1KM)


Detachable antenna for TRP-C51


1.8M D-SUB 9 pin female to female Null-Modem cable

PC to TRP-C51A ( TRP-BT Utility use)

PWR-AD12VAuto (Option)

Switching Adaptor

Input:100~240VAC 50/60Hz 260mA

Output: DC 12V/1A

Certificate: CE, FCC, UL, PSE

US Specification  

We also provide the EU / AUS / British specifications(MOQ:50PCS/2 Weeks)……more

DIN-RAIL-R (Option)

DIN rail mounting adapter