The Chiyu BF-430 is an RS-485/RS-232 to Ethernet converter that is required for serial communication to third-party devices (for example, Modbus RTU) on older eGauge models without USB ports. eGauge models with USB ports can utilize the eGauge RS485 to USB adapter.

The eGauge sends data to the BF-430 over the Ethernet network, and the BF-430 in turn sends the data to the third-party device over the serial line. When the device on the serial line responds, the BF-430 relays that data to the eGauge.

The BF-430 can accommodate one RS-232 slave device, or multiple RS-485 slave devices. If there are multiple slave devices on the RS-485 line, all devices must communicate using the same protocol and bus settings (including but not limited to: baud rate, parity, data bits, and stop bits). The RS-232 and RS-485 ports cannot be used simultaneously. Only one master unit (i.e., the eGauge) may request data from the BF-430 at a time.

The BF-430 is powered by 9–30Vdc, via power terminals or a standard barrel jack plug. The Chiyu BF-430 contains an embedded web server that is used for configuration and diagnostics.

The Chiyu BF-430 image is currently unavailable

The most common attributes that must be adjusted on the BF-430 are:

  • Baud rate
  • Data bits
  • Stop bits
  • Parity check

These attributes can be adjusted from the Serial Type menu under Advanced Setup, or the settings can be pre-set for specified devices prior to shipping when ordered from eGauge Systems. Please specify the device type(s) when ordering.

Some troubleshooting and verification can be done on the web interface of the BF-430. For example, verification of the correct serial settings from the Serial Type menu, and verification of communication on the serial port from the System Status menu. The full manual for the Chiyu BF-430 can be found here.

The format for remote Modbus RTU device via BF-430 is as follows:



DEVTYPERemote device type or inline Modbus register definitions. See this Knowledgebase article for inline definition descriptions
SLAVE_ADDRSerial Modbus address (0-255) of the device
CONV_ADDRBF-430 converter MAC address or IP address
PORTThe port-number of the RS-485 to Ethernet adapter or host (unspecified default: 50,000)