USB-to-RS485 Converter Board for Laurel Electronics 1/8 DIN Instruments

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USB-to-RS485 device server board

Key Features

Suitable for all 1/8 DIN Laureate DPMs, counters, timers & remote displays.
Connects host meter to a computer via USB 2.0 while also acting as server
for up to 31 Laurel device on an RS485 network.
Includes USB Type-B receptacle plus an RJ11 jack for connection to
RS485 bus.
Selectable baud rates to 19,200.
Powered by instrument.
Isolated from meter and power grounds.

Description

The Laureate USB-to-RS485 Converter Board can connect up to 31 Laurel meters and counter on an RS485 bus to a computer wity a USB port. It features a USB Type-B connector for connection to a PC via a standard USB cable, plus an RJ11 jack for interface to an RS485 bus which can support up to 31 Laurel meters equipped with Laurel's RS485 interface board. That board features dual RJ11 connectors for RS485 daisy-chaining using commercial 6-wire RJ11 data cables, with no need for a hub.

Network of Laurel meters connected to a PC via USB-to-RS485 device server

The USB board is shipped with a driver on a mini CD ROM. That driver will will assign a COM port address to the connected USB device, which is then treated like an RS232 device, making the presence of the USB line transparent to the user and PC software. The individual meters, including the host meter, are selected in software by their own digital address, which can be entered from the meter front panel or by using Laurel's free Windows-based Instrument Setup Software.

Three serial protocols are user-selectable: Modbus RTU, Modbus ASCII, and Laurel ASCII. The Laurel ASCII protocol is the simplest and is recommended if Laureates are the only devices on the network. For more information, please see our Modbus Protocol Serial Communications Manual and our Serial Communications Manual. The Laurel Laurel ASCII protocol supports 31 device addresses, one of which needs to be the converter board. The two Modbus protocols support 247 device addresses; however, only 31 addresses can be electrically driven on an RS485 line without a repeater.

Multiple meters on an RS485 bus can also be digitally addressed using our Ethernet-to-RS485 converter board, which is normally connected to an Ethernet network router via an Ethernet line.

Installation

The Laureate USB-to-RS485 converter board provides a USB Type-B connector for a standard USB cable to a PC, RJ11 connector for connection to an RS485 bus with up to 31 Laurel meters and transmitters. The required USB cable is readily available in computer stores and also from Laurel as P/N CBL05.