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BASgatewayLX Modernizes Modbus

Contemporary Controls is a big fan of Modbus as an open and free communication protocol. Its simplicity and versatility are still leveraged in boiler controls, variable speed drives, and metering applications. But in the IoT age when more modern communication uses a TCP/IP network, the BASgatewayLX modernizes Modbus by enabling Modbus devices to be BACnet compliant.

The BASgatewayLX is used to make Modbus devices appear as individual BACnet devices, allowing for integration into control systems that utilize BACnet. The BASgatewayLX has one 10/100 Mbps TCP Ethernet port supporting Modbus TCP and BACnet/IP and an opto-isolated Modbus EIA-485 serial port for Modbus RTU or Modbus ASCII devices. Up to 100 Modbus devices and as many as 1,000 polled points can share the Modbus EIA-485 port on the BASgatewayLX. All that is needed is a device profile for each Modbus device. Contemporary Controls maintains a free library of common device profiles for download in the Modbus Mapping Support section of our website. If your desired device profile is not available, we will create one for you free of charge. Once the device profile is developed, it is installed into the BASgatewayLX and a scan list is created.

The beauty of Modbus TCP is that it is an IP bus. Instead of having one master attached to multiple slaves, Modbus TCP becomes a client/server network where clients become HMIs or PLCs and servers could be multiple serial input/output racks linked via gateways such as the BASgatewayLX. Several clients can reside on the IP network and access a common set of servers. There is no single master controlling a defined set of slaves. Devices scanned by the BASgatewayLX become available to the TCP clients for control or data collection.

Unlike most competitors, the BASgatewayLX can be powered from 24-volts AC or DC, making it versatile for situations where a DC supply is not available. It is DIN rail or panel mounted (model dependent) with an industrial grade metal case, wide temperature range and UL508 approval; characteristics that make for a quick install in control cabinets. The optically isolated serial port allows for connection to either 2-wire or 3-wire EIA-485 networks and the Ethernet port offers a shielded RJ-45 connector. Through auto-negotiation and auto-MDIX, the BASgatewayLX automatically matches connections to the Ethernet network, allowing for either straight-through or crossover cabling. A resident web server allows for commissioning and troubleshooting via a standard web browser.

Learn more about how to modernize Modbus on the BASgatewayLX product page.


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