Korenix JetNet 3705, JetNet 3705 Series User Manual

Korenix JetNet 3705 Series

Industrial Power over Ethernet Switch

User’s Manual

First Edition, April 2006

www.korenix.com

Korenix JetNet 3705 Series

Industrial Power over Ethernet Switch

User’s Manual

Copyright Notice

Copyright © 2005 Korenix Technology Co., Ltd.

All rights reserved.

Reproduction in any form or by any means without permission is prohibited.

FCC Warning

This Equipment has been tested and found to comply with the limits for a Class A
digital device, pursuant to Part 15 of the FCC rules. These limits are designed to
provide reasonable protection against harmful interference in a residential installation.
This equipment generates uses and can radiate radio frequency energy and, if not
installed and used in accordance with the instructions, may cause harmful interference
to radio communications. However, there is no guarantee that interference will not
occur in a particular installation. If this equipment does cause harmful interference to
radio or television reception, which can be determined by turning the equipment off
and on, the user is encouraged to try to correct the interference by one or more of the
following measures:

 Reorient or relocate the receiving antenna.
 Increase the separation between the equipment and receiver.
 Connect the equipment into an outlet on a circuit different from that to which the

receiver is connected.

 Consult the dealer or an experienced radio/TV technician for help.

CE Mark Warning

This is a class A product. In a domestic environment this product may cause radio
interference in which case the user may be required to take adequate measures.

Table of Contents

FCC Warning....................................................................................................... 1

CE Mark Warning................................................................................................1

Chapter 1 Introduction.............................................................................................1-1

Overview...........................................................................................................1-2

Ethernet Switching Technology........................................................................1-2

Power over Ethernet Technology.....................................................................1-4

Product Features..............................................................................................1-5

Package Checklist............................................................................................1-5

Chapter 2 Hardware Installation..............................................................................2-1

Introduction....................................................................................................... 2-2

Dimension of JetNet 3705 and 3705f series.............................................2-2

Panel Layout .............................................................................................2-2

LED Indicators..........................................................................................2-3

DIP Switch................................................................................................2-4

Wiring the Power Inputs ...................................................................................2-4

Wiring the Relay Output ...................................................................................2-5

Wiring the Ethernet Ports .................................................................................2-6

Connecting to PD .............................................................................................2-1

Wiring the Fiber Ports ( JetNet 3705f series) ...................................................2-2

DIN-Rail Mounting Installation.......................................................................... 2-2

Chapter 3 Troubleshooting......................................................................................3-3

Power Connections ..........................................................................................3-4

Incorrect Connections.......................................................................................3-4

Faulty or Loosen Cables ...........................................................................3-4

Non-standard Cables.................................................................................3-4

Improper Network Design ........................................................................3-4

LED Indicators..................................................................................................3-5

Appendix A Specifications.........................................................................................A-1

Appendix B Revision History.....................................................................................B-1

11

Chapter 1 Introduction

Korenix JetNet 3705 Series is a power over Ethernet rail switch that is specially designed for
industrial or commercial applications.

The following topics are covered in this chapter:

Overview
Ethernet Switching Technology
Power over Ethernet Technology
Product Features
Package Checklist
Installation Guide

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Overview

JetNet 3705 Industrial Power Over Ethernet (PoE) Switches have four ports 10/100 TX ports
with PoE injector plus one 10/100TX up-link port( JetNet 3705 ) or four ports 10/100 TX ports
with PoE injector plus one 100FX up-link port (multi-mode “-m” or single-mode “-s” models,
JetNet 3705f ). It is designed to operate under harsh environmental conditions. The switches
provide Power over Ethernet functions to deliver 15.4Watts power budget to powered device
(PD), which is in compliance with IEEE802.3af standard to deliver both of Ethernet data and DC
48V power through the traditional UTP or STP cable to the PD. The IP30-design aluminum case
further strengthens JetNet 3705 's withstand ability in harsh industrial environments. The event
warning is notified to field engineers by relay output triggering field alert system. JetNet 3705
Series Industrial PoE Switch has passed CE/ FCC/ UL safety certifications to help ensure safe
and reliable data transmission for industrial applications. JetNet 3705 Series will be your best
option for industrial network or security sy st em.

Ethernet Switching Technology

To better understand the operation of an Ethernet switch, we need to first differentiate it from a
hub. An Ethernet hub (or repeater) is a device that is used to simply connect Ethernet nodes.
Any message at one hub port is repeated on all ports. That is, hubs forward data packets they
receive from a single station to all

hub ports. As a result, all port devices connected to a single
hub will share the same bandwidth. Then as nodes are added to the network hub, they compete
for this finite amount of bandwidth and this can cause data collisions to occur, making network
determinism impossible to attain, especially on busy networks. Now determinism is a term that i s
used to describe the ability to guarantee that a packet is sent or received in a finite and
predictable amount of time. The inherent lack of determinism is the main reason that traditional
Ethernet had problems being accepted for use in critical control applications, as most control
systems have a defined time requirement for packet transmission, typically less than 100ms.

Introduction

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Switches on the other hand, are intelligent devices used to more efficiently connect distributed
Ethernet nodes than a hub. Unlike a simple hub, a switch provides targeted data transfer, as it
will forward a data packet to a specific port or network segment, rather than to all ports, thus
freeing up bandwidth. The ability to target a packet to a specific port increases network
throughput and helps to eliminate the collisions that have historically made Ethernet
non-deterministic.

So we see that by targeting the data transfer between ports, switches act as intelligent repeaters
to increase network distances. In doing this, they actually split networks into separate collision
domains at each port. Thus, switches increase determinism by reducing collisions. Switches also
increase network bandwidth and throughput, as well as provide supplemental error checking on
data packets to help ensure the integrity of forwarded dat a. Each port of this switch function s just
like any other Ethernet device. It is able to receive and decode Ethernet frames, test for frame
integrity, plus assemble and transmit Ethernet frames.

With Ethernet, any device can try to send a data frame out at any time. If two devices happen to
send a data frame at the same time, then a collision may occur. The arbitration protocol for
carrier transmission access of the Ethernet network is called Carrier Sense Multiple Access with
Collision Detect (CSMA/CD). With CSMA/CD, each device will first sense whether the line is idle
and available for use. If it is, the device will begin to transmit its first frame. If another device also
tries to send a frame at the same time, then a collision occurs and both frames are discarded.
Each device then waits a random amount of time and retries its transmission unt il it is
successfully sent.

Unlike other Ethernet devices, such as an Ethernet host adapter or Network Interface Card (NIC),
the port of a switch does not require its own MAC address. During retransmission of a received
packet, the switch port will instead look like the originating device by having assumed its source
address. This is why the Ethernet collision domain is said to terminate at the switch port. That is,
a two-port switch will effectively break a network into two distinct data links or segments. The
JetNet 3705 and JetNet 3705f Industrial Ethernet Switch can break a network into 5 distinct data
links or segments (also called collision domains). Since all Ethernet nodes are able to reco gnize
the occurrence of a collision, and since the detection of a collision is principal to the way Ethernet
arbitrates media access, large domains containing many nodes can become quite cumbersome.
Thus, using an Ethernet switch to subdivide a large network into separate collision domains will
certainly help to increase throughput.

The current tendency in critical industrial control applications is to connect one Ethernet device
per switch port. This will produce the most deterministic mode of operation as the switch can
then operate full-duplex, with no chance of collisions. This ensures determinism, helping critical
control applications to remain predictable and on-time.

Each port of a switch forwards data to another port based on the MAC address contained in the
received data packet/frame. In order to know which port to forward a data packet to, the switch
will learn and store the MAC addresses of every device it is connected to, along with the
associated port number. Howeve r, until the switch actually learns the port a p articular address
resides at (the first packet), it forwards this traffic to all port s just like a hub. The switch will u se its
internal look-up table to quickly determine the location (port) of a node, establish a temporary
connection between itself and the node, then terminate the con nection once a packet is
transferred. In this way, it increases network bandwidth and provides the network determinism
required for critical control applications.

JetNet 3705 and JetNet 3705f Series Industrial Power over Ethernet Switch uses a store and
forward algorithm to process Ethernet frames. That is, it first stores the Ethernet frame and
examines it for errors before forwarding it to its destination. Although this method may seem to
increase the forwarding time (latency) and possibly cause fragmentation, it effectively reduces
the occurrence of error frames and improves overall throughput. This is particularly useful when
there is heavy network traffic and or greater potential for noise and interference.

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The industry-wide shift from Ethernet hubs to Ethernet switches has dramatically boosted the
bandwidth of networks and helped to eliminate congestion problems inherent with the CSMA/CD
protocol (Carrier Sense Multiple Access with Collision Detection). Since a switch operates by
learning the location of addresses and forwarding messages directly, unnecessary traffic is
greatly reduced. It will use auto-negotiation to regulate the speed and duplex of each port based
on the capabilities of connected devices. These features combine with flow control allow a 100M
node to effectively communicate with a 10M node without losing data. Connecting one device
per switch port also allows two-way, simultaneous transmission to occur (full duplex), essentially
doubling the bandwidth. Further, by segmenting a collision domain in this way, the need for
non-deterministic carrier sensing (CSMA/CD) is eliminated. The utilization of a store-and-forward
switching algorithm allows each packet to be inspected, and corrupt or redundant data to be
filtered, further eliminating unnecessary traffic that often slows a network down.

Power over Ethernet Technology

Power over Ethernet is a revolutionary technology that allows IP telephones, wireless LAN
Access Points, Security network Cameras and other IP-based terminals to receive power an d
data in parallel. The Power over Ethernet can bring a lot of benefits, such as cost saving,
simplicity, reliability, safety, control and security.

The IEEE802.3af (Power over Ethernet) is established on June 2003, which defined how to
deliver DC 48V power and Ethernet frame through the traditional cabling system.

PoE architecture includes 2 elements, Power Sourcing Equipment (PSE) and Powered Device
(PD), PSE device

provides auto detection capability to recognize the characteristics of link

partner to deliver exactly power to the PD, it also will not damage the link partner if it is not a PD
or the link cable is short, or the device is broken, and execute a series of standard procedure
when the PD is disconnected to avoid send out a huge power to damage the device or user

.

The IEEE802.3af standards have specified the architecture and the type of PSE, PSE supports 2
different types, End-point and Mid-Spain for the different power feeding model and wiring.

In the IEEE803.3af also specified the PD should compatible with End-point and Mid-Spain PSE,
and exactly, honestly claims the level of power consumption.

JetNet 3705 equips 4 PoE injector switch ports, with each port delivering power up to 15.4 watts
in maximum, and one 10/100Base TX Up-link port transferring data to remote end. The JetNet
3705 conforms to IEEE 802.3af Power over Ethernet (PoE) standard. Using an external 48VDC
power supply, JetNet 3705 enables power and data transmission to be pumped out over the
same UTP or STP cable in the four PoE ports.

JetNet3705 is in compliance with IEEE 802.3af standard and supports Power Sourcing
Equipment (PSE) function. It delivers power through the spare pairs (4, 5, 7, 8) of standard
Ethernet CAT-

5 cable and transmits data through the traditional pairs (1, 2, 3, 6). The
JetNet3705 PoE ports provide PoE auto detection of the link partner to deliver the exact power
to the PD. If the link partner is not a PD or the link cable is short, or the device is broken, it will
executes a series of standard procedures to avoid sending out a huge power to damage the
linked device.