
Description
LAUREL
ELECTRONICS, INC.
LTNET485 DIN Rail Mounted
Ethernet-to-Serial Device Server
Connects up to 31 meters & transmitters to the Ethernet via an RS485 bus
Features
•
Interfaces to the Ethernet via an RJ45 jack.
•
Mounts to 35 mm DIN rail.
•
Universal AC power, 85-264 Vac
•
Optional low voltage power, 10-48 Vdc or 12-32 Vac
•
Priced at only $150
•
DHCP server capability assigns a local IP address to the server
and computer if necessary.
Network with an LTNET485 Ethernet-to-RS485 Device Server
The LTNET485 DIN Rail Ethernet-to-Serial Device Server
provides a 10/100BaseT interface to the Ethernet and serves as
an Ethernet-to-RS485 converter and device server for a mix of up
to 31 Laurel meters and transmitters on an RS485 bus. The
Ethernet connection is via a standard RJ45 jack. The connection
to the RS485 bus can be via an RJ11 jack or via discrete screw
terminals. The lines of the RJ11 jack and the screw terminals are
wired in parallel.
Priced at only $150, the LTNET485 is a very economical and
easy means to interface different types of Laurel transmitters to
an Ethernet LAN and to the Internet. The transmitters can be any
mix of analog input types (voltage, current, AC, DC, strain gauge,
load cell, thermocouple, RTD, ohms) and pulse input types
(frequency, rate, totalizing, quadrature position or rate, period,
elapsed time, sum, difference or ratio of two inputs).
Laurel transmitters come with RS485 I/O as a standard feature
and can be connected to the LTNET485 Device Server using
screws terminals and 3 discrete parallel wires (half-duplex
RS485) or 5 discrete parallel wires (full-duplex RS485), with no
need for a hub. This includes LTA transmitters and LTM
transmitters.
LAUREL
ELECTRONICS INC., 3183-G Airway Ave., Costa Mesa, CA 92626, USA • Tel 714-434-6131 • www.laurels.com 1
Laurel meters to be connected to the LTNET485 Device Server
need to be equipped with an RS485 option board with dual RJ11
jacks (digital interface ordering option 2). Multiple meters can
then be daisy-chained using readily-available commercial 6-wire
straight-through data cables (not crossover cables), with no need
for a hub.
As an alternative, multiple Laurel meters can be interfaced to a
single Ethernet line via an Ethernet-to-RS485 Converter Board in
one of the meters. That board offers an RJ11 jack for connection
to the RS485 bus as required for meters (like the LTNET485), but
not screw terminal connectors as required for Laurel transmitters
(unlike the LTNET485). Individual Laurel meters equipped with
an Ethernet interface board can also be interfaced to a single
Ethernet line.
Discovery and configuration of Ethernet nodes and their
connected devices can be achieved by two alternate methods
using a PC connected to the same LAN as the Nodes: 1) a
Console mode which uses Windows-based Node Manager
Software, and 2) a Webserver mode which uses a browser to
access the public or private IP address of the node.

Both methods automatically discover all Nodes on a LAN or
WAN, plus any devices connected to each Server Node via an
RS485 bus. They are used to configure each Node, such as
setting communication parameters, naming the Node and associated devices, entering email addresses for alarm notification
and data requests, selecting the Node's time zone for timestamping of emails and streaming data, and upgrading firmware.
Once configuration data has been stored in flash memory of all
Nodes, the PC can be disconnected. Details are in our Ethernet
Manual.
Specifications
Serial Data I/O
Supported protocols
Ethernet connection
Ethernet cable
Ethernet compliance
Devices per Ethernet line
RS485 connection
RS485 compliance
Devices per RS485 line
Data rates to Laurel devices
Rates to non-Laurel devices
Isolation
ESD Protection
EMI Immunity
EFT Protection
Short Circuit Protection
Power Input
Standard Power
Low Power Option
Power Frequency
Power Isolation
Power Consumption
Mechanical
Dimensions
Mounting
Electrical Connections
Environmental
Operating Temperature
Storage Temperature
Relative Humidity
Cooling Requirement
Modbus TCP, Modbus RTU, Modbus ASCII, Laurel ASCII
RJ45 jack
10/100Base-T
IEEE 802.3
Server Node plus up to 31 Laurel devices on RS485 bus
RJ11 jack plus five screw terminals for discrete data wiring.
EIA/TIA-485
Up to 31 Laurel meters and transmitters.
300, 600, 1200, 2400, 4800, 9600, 19200 baud
Up to 614400 baud
250V rms working, 2.3 kV rms per 1 min test
15 kV per IEC 1000-4-2
10 V/m per IEC 1000-4-3
2 kV per IEC 1000-4-4
Continuous
85-264 Vac or 90-300 Vdc (DC operation not UL approved)
10-48 Vdc or 12-32 Vac
DC or 47-63 Hz
250V rms working, 2.3 kV rms per 1 min test
2W typical, 3W with max excitation output
129 x 104 x 22.5 mm case
35 mm rail per DIN EN 50022
Plug-in screw-clamp connectors
0°C to 55°C
-40°C to 85°C
95% at 40°C, non-condensing
Mount transmitters with ventilation holes at top and bottom.
Leave 6 mm (1/4") between transmitters, or force air with a fan.
Instruments from other manufacturers can be operated on the
RS485 bus under control of our LTNET485 Ethernet-to-Serial
Device Server if the host computer supplies commands and
accepts responses suitable for these instruments.
The LTNET485 mounts on a DIN rail. It looks like a Laurel
transmitter, but does not include a signal conditioner board or
relays
Pinout
LAUREL
Ordering Guide
Create a model a model number in this format: LTNET485-1
Transmitter
Type
Power 1 Isolated 85-264 Vac
LTNET485 Laureate Ethernet-to-Serial
Device Server
2 Isolated 12-32 Vac or 10-48 Vdc
ELECTRONICS INC., 3183-G Airway Ave., Costa Mesa, CA 92626, USA • Tel 714-434-6131 • www.laurels.com 2