Overview; Installation; Heartbeat Configuration; Table 1: At-200 Series Single Port Transceivers - Allied Telesis CentreCOM AT-200 Series User Manual

Overview

CentreCOM™ AT-200 Series Single Port Transceivers are highly reliable compact
Media Access Units (MAUs) for users of Ethernet Local Area Networks (LANs).
They provide the electronic and physical interface between the IEEE 802.3 coaxial
cable and a Data Terminal Equipment (DTE) station.
The AT-200 transceiver is available in a variety of configurations, all of which meet
the transceiver compliance requirements of IEEE 802.3 and are compatible with
Ethernet Version 1.0 and 2.0. The use of industry-standard connectors ensures
plug compatibility with all existing cable connectors used in Attachment Unit
Interface (AUI), thicknet (10BASE5) or thinnet (10BASE2) installations.
Table 1 shows the AT-200 series transceiver models available.
Model
AT-204
AT-205
AT-206
AT-207
AT-208

Installation

Installation of an AT-200 series transceiver involves checking heartbeat
configuration, installing the tap body (if it is shipped separated or has been
removed) and connecting the cables properly. The AT-204, AT-207 and AT-208 are
shipped with the coaxial tap body installed. With the AT-206, you install the coaxial
active tap body when you tap the 10BASE5 cable. The AT-205 comes with no tap
body.
Heartbeat configuration
All transceivers are shipped with the Heartbeat switch in the "0"
Note
(disabled) position.
With few exceptions, the Signal Quality Error (SQE)/Heartbeat (i.e., Collision
Presence Test) should be disabled; i.e., the Heartbeat switch should be left in the
"0" (disabled) position. Check the device's documentation to determine whether to
enable SQE/Heartbeat. In most cases, when the AUI port is connected to a
repeater or another node, the switch must be set to "0" to eliminate the possibility
of excessive collisions. The switch should be set to "1" (enabled) with some older
Data Communication Equipment (DCE) repeaters and Network Interface
Controller (NIC) cards that take advantage of the heartbeat signal.

Table 1: AT-200 Series Single Port Transceivers

Cable
10BASE2
N/A
10BASE5
10BASE2
10BASE5
Connector
Bayonet Nut Couple (BNC)
No Backbone Connector
Coaxial Active (Stinger) Type Tap
BNC-T
Coaxial N-Series
1