IBM AS/400e, Руководство пользователя

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Peripherals
427
Peripherals
Each device can be connected directly to the multiplexer using star topology and a patch
panel, removing the need for daisy chaining twinaxial devices. Hubs may also be connected
to the multiplexer that are then connected to the devices.
The 7299 Express Multiplexer supports connectivity options of shielded or unshielded twisted
pair, optical fiber, and a high-speed DB25 cable. The various distance limitations are
described in the following table.
The 7299 supports the 5250 Express Data Stream providing speed improvements of up to
four times. The 5250 Express Data Stream also requires an IBM 5250 Express ISA, PCI, or
PC adapter card in a supported PC. The 7299 supports dual mode operation when attached
to the AS/400 workstation controllers 2722 or 6180. Dual mode operation means that a port
between 0 and 3 and a port between 4 and 7 are being poled at the same time on these eight
port workstation controllers.
IBM 5250 Express Network Kit
Using the V4R2 enhancement of TCP/IP over twinax cabling, it is possible to have non-LAN
PCs access the World Wide Web, share printers, and files, and to use workgroup applications
such as Lotus Notes using Express 5250 Adapters.
It is intended for customers with PCs attached to twinax workstation controllers, sites with
large investments in twinax cabling, or twinax to NTP hubs, or sites with nonprogrammable
workstations intending to migrate to PCs. One of the benefits of running TCP/IP over twinax
is that it supports cable distances of up to 5,000 feet of twinax without any kind of repeater or
4,200 feet using one active 7299 Express Hub. This is longer than many LAN types that
require additional hubs to attain this distance.
The prerequisites to running TCP/IP over twinax include any model of AS/400 running
OS/400 V4R2 or later; all 5250 Express ISA, PCI, or PC adapter cards, or certain specific
Enhanced 5250 Display Station Adapters (part numbers 92G5364 or 884H0240); and a PC
with a card slot running Microsoft Windows 95 (with the latest updates) or Windows NT
Version 4.0 or later.
The adapters can be attached to the AS/400 system using twinax, Unshielded Twisted Pair
(UTP), Foiled Twisted Pair (FTP), or the IBM Cabling System (ICS). The twinax workstation
Connection UTP Cat 3 at
1 Mbps
UTP Cat 5 at
1 Mbps
UTP Cat 5 at
2 Mbps
Optical Fibre High-Speed
DB25 Cable
Host to Mux
Mux to Mux
Mux to Device
Mux to Hub
2000-ft/610m
1800-ft/548m
1000-ft/305m
2000-ft/610m
2200-ft/671m
1200-ft/365m
1500-ft/457m
1650-ft/503m
900-ft/274m
6600-ft/2012m
900-ft/270m
90-ft/27.3m