Ethernet Interface Board for Laurel Electronics 1/8 DIN Instruments

The basic Laureate Ethernet interface board plugs into a host 1/8 DIN digital panel meter, counter or timer to provide a 10/100Base-T Ethernet interface via an industry-standard RJ45 connector. Multiple meters, each with its its own Ethernet cable, can be connected to a local area network (LAN) or to the Internet via a router, or directly to a host computer. LAN, WAN, and Internet connectivity are fully supported so that the meter can be read and set up remotely.

Laurel's Node Manager software is shipped on a mini CD with each Ethernet board. This free Windows-based application automatically discovers all Laurel Nodes (or Laurel Ethernet boards) on a LAN or WAN, plus the host meter connected to the Node. Node Manager software is also used to configure each Node, such as naming the Node and associated devices, entering email addresses for alarm notification and data requests, selecting the Node's time zone for time-stamping of streaming data, and setting communication parameters for associated meters. Please see our Ethernet Manual.

On a Wide Area Network (WAN), such as the Internet, the host computer is outside of the LAN and therefore must know the public IP address of the LAN router to discover the Laurel Nodes. If the public IP address of the router is not known or becomes unknown because it is dynamic rather than a static, the host computer can accomplish the discovery by interrogating a Resolution Server computer located at our factory.

Built-in DHCP server capability allows Laurel Nodes to constitute themselves into a network and be connected directly to a host computer when no router or dedicated DHCP server is present, as illustrated above. When a Node fails to find a DHCP server that responds to its request for a private IP address, it assigns one. When several Nodes fail to receive a Private IP address, they mutually agree to make one of the Nodes a temporary DHCP server that assigns a Private IP address to each device on the network.

Data can be sent by Laurel Nodes in the form of real-time stream data, or in the form of emails. Accuracy of streaming data is ensured by filtering and by dual checksums. Emails can be sent in response to email requests from the host computer, periodically, or when devices encounter an alarm condition or go off-line.

The Modbus TCP protocol is fully supported. Conversion to Modbus TCP is provided transparently by Laurel Nodes so that an Ethernet application program can use the Modbus TCP protocol while the meters use the Modbus RTU or Modbus ASCII protocol. The Laurel ASCII protocol, which supports up to 31 digital addresses, can also be used if the only devices on the data line are Laureate meters.

Laurel's Ethernet to RS485 converter board can be used as an alternative to networking multiple meters each with its own Ethernet cable. The converter board can be connected to an a single Ethernet router port and also act as the server via an RJ11 connector for up to 31 meters on an RS485 bus. The remote meters must be equipped with Laurel's RS485 interface board. Each interface board provides dual RJ11 connectors, so that meters can be daisy-chained with no need for a hub. All meters on the RS485 bus are easily discovered by Node Manger software. Please see our Ethernet Manual.