Installation Guidelines - DEC VAXmate Service Manual

Thin Wire Ethernet
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g. The instructions on the screen are to unplug the network cable from
the VAXmate workstation and to plug in the network port loopback
connector. However, you have already done this.
h. Press any key to start the test.
i.
When the test is complete, reconnect the VAXmate workstation to the
network.
A successful test means the V AXmate Ethernet logic is functioning
correctly. If the test fails, replace the I/O board. Then run the Power-
Up test, Extended Self-Test and the Service Diagnostics network tests.
3.4
Installation Guidelines
Note the following about ThinWire installations.
• Each VAXmate workstation is shipped with a section of ThinWire cable,
a T-connector, and one terminator (50-ohms).
• The maximum length of a Thinwire segment is 185 meters (606 feet).
Thirty stations (or up to a combination of 60 male/female connector
junctions) can be connected to a single segment. When a DEMPR is
used, 29 can be connected to each segment of ThinWire cable - the
DEMPR is counted as one connection.
• Stations can be attached directly to the cable segment using T-connec-
tors. T-connectors plug directly into the station.
• There must be at least 0.5 meters (1.6 feet) between ThinWire station
connectors.
• A maximum of eight ThinWire segments can be connected to a DEMPR
to form a network of up to 232 stations. A DIGITAL Ethernet Local
Network Interconnect (DELNI) can be used to concentrate up to eight
DEMPRs. These configurations can either stand alone or connect to the
standard Ethernet using an H4005 transceiver .
• The Ethernet limit of 1024 devices can be configured in a single
ThinWire Ethernet network (using DEMPRs and DELNls) .
• A maximum of 60 connector junctions are allowed in one ThinWire
segment. T-connectors and barrel connectors each count as two connec-
tor junctions. A DIGITAL faceplate counts as one junction. A DEMPR
also counts as one junction.
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