Overview

The eGauge USB485 converter functions as a standard serial-to-USB adapter, allowing a computer to read data from an eGauge or communicate with other third-party devices. It uses the FT230X chipset from FTDI, and most modern systems should have the necessary drivers pre-installed. If needed, drivers can be downloaded from FTDI's website, and COM port drivers are available here.

This guide explains how to check if the USB485 converter is recognized on Windows 10 and demonstrates data reading from an eGauge using QModBus and two USB485 converters.

Instructions

Step 1: Plug the eGauge USB485 into the Windows 10 computer. Within a few minutes, a notification should appear confirming the drivers are ready. If not, check the USB cable connection and proceed to the next step.

Step 2: Open Device Manager by pressing Win + R, typing devmgmt.msc, and clicking OK. You can also search for "Run" in the Start menu, open it, and enter the same command.

Step 3: Under "Universal Serial Bus controllers" you should see "USB Serial Converter":

Step 4: You can determine the COM port by expanding "Ports (COM & LPT)". Here, it is COM3:

Step 5: You can install QModBus from this link. eGauge Systems does not endorse or verify its legitimacy. If no serial converters are detected when you run QModBus, a warning will appear.

Step 6: If a serial converter is detected, QModBus will automatically select one (e.g., COM3). We configure the serial settings to match an eGauge Modbus slave connected via USB485. In the example below, registers 1012 and 1013 are read, as DC voltage is stored as a 32-bit float starting at 1012. Converting 0x4143 and 0xB07B as a big-endian float gives a DC voltage of 12.23V.