Ethernet Units Operation Manual

Precautions Section 1-8

1-8 Precautions

Be sure to observe the following precautions when installing and using an

Ethernet Unit.

1-8-1 Installation

Observe the following precautions when installing an Ethernet System. (Refer

to Section 3 Installation and Initial Setup for details.)

1,2,3... 1. Use transceiver cable that meets IEEE802.3 standards to ensure high

noise resistance.

2. Use a transceiver with a current consumption of not more than 0.4 A per

port.

3. Always turn off the power supply to the PC before connecting or discon-

necting the transceiver cable.

4. Be sure not to exceed the current capacity of the Power Supply Unit on the

Rack to which the Ethernet Unit is mounted. The current consumption of

the CS-series Ethernet Units is 400 mA maximum and the current con-

sumption of the CJ-series Ethernet Unit is 380 mA maximum. This value

added to the current consumption of all other Units mounted to the same

Rack must not exceed the capacity of the Power Supply Unit.

5. Do not install the transceiver cables or coaxial cables of the Ethernet Sys-

tem near power supply lines. If installation near possible sources of noise

is unavoidable, install the cables in grounded metal ducts or take other

measure to eliminate noise interference.

1-8-2 Ethernet and IEEE802.3 Standards

The Ethernet Unit was designed based on version-2 Ethernet standards and

not on the international IEEE802.3 standards, which were developed based

on Version-2.0 Ethernet specifications. Although these two sets of standards

are similar, they are not necessarily the same. Particularly, different frame for-

mats are used, making direct communications impossible between systems

that do not support the same standards. Standards for equipment used to

configure networks are the same, allowing IEEE802.3-standard equipment to

be used with the Ethernet Unit. Particularly the transceiver cable for the

IEEE802.3 standards provides superior noise resistance and should be used

for the Ethernet Unit.

Terminology also differs between Version-2.0 Ethernet and IEEE802.3 stan-

dards. These differences are shown in the following table. Version-2.0 Ether-

net terminology is used in this manual.

Version-2 Ethernet IEEE802.3

Tra ns ce ive r MAU

Transceiver cable AUI

Ethernet address MAC address

Ethernet 10Base-5/10Base-T