The laureate LNET Ethernet interface board plugs into the middle slot of a host 1/8 DIN digital panel meter, counter or timer to provide a 10/100 Base-T Ethernet interface via an industry-standard RJ45 connector. Multiple meters, each with its own Ethernet cable, can be connected to a local area network (LAN) or to the Internet via a router, or be connected directly to a host computer. Internet connectivity is fully supported so that the meter can be set up and read remotely.
Instrument Setup (IS) software is a free Windows-based application which automatically discovers all Laurel Ethernet Nodes on the same Local Area Network (LAN) as the PC, plus the host device (or Laurel instruments) associated with that Node. As an alterntive to front panel programming, IS software can be used to set up the instrument, such as scaling the reading, scaling analog outputs, setting setpoints, and more.
Node Manager software is also a free Windows based application which automatically discovers all Laurel Ethernet Nodes on the same Local Area Network (LAN) as the PC. Its capabilities include 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 data, and setting communication parameters for associated meters. It allows emails or text messages to be sent in response to requests from the host computer, periodically, or when devices encounter an alarm condition or go off-line. It is described in our Ethernet Manual. Unlike IS software, Node Manager software cannot be usedto set up the instrument, such as scaling the reading, scaling analog outputs, or setting setpoints. However, all such setup parameters can be set remotely by a Master using the Modbus TCP protocol.
On a Wide Area Network (WAN), such as the Internet, the host computer is outside of the LAN and must know the public IP address of the LAN router to discover Laurel Nodes. Web server software built-into each Node can also be used to discover and configure Laurel Nodes over the Internet..
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 to the right. 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.
The Modbus TCP protocol is fully supported. Modbus command cannot only be used to read meters remotely, but also to change setup parameters like setpoints. Conversion to form Modbus RTU to Modbus TCP is transparent so that an Ethernet application can use the Modbus RTU protocol.
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 gateway 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 with dual RJ11 connetors. These allow the remote meters to be daisy-chained with no need for a hub. All meters on the RS485 bus are easily discovered by our Instrument Setup software or Node Manager software. Please see our Ethernet Manual.
|LNET Ethernet Board Specifications|
|Data rates||300, 600, 1200, 2400, 4800, 9600 baud|
|Meter per Ethernet line||1 Node|
|Ethernet connector||RJ45 jack|
|Ethernet cable||10/100 Base-T|
|Ethernet compliance||IEEE 802.3|
|Isolation||250V rms working, 2.3 kV rms per 1 min test|
|ESD Protection||15 kV per IEC 1000-4-2|
|EMI Immunity||10 V/m per IEC 1000-4-3|
|EFT Protection||2 kV per IEC 1000-4-4|
|Short Circuit Protection||Continuous|
|Communication Protocol||Modbus TCP|
|Standards Compliance||Modbus over Serial Line Specification V1.0 (2002)|
|Conversion from RTU to TCP||Automatic|
|Protocol Type||Master-slave, query-response command mode.|