IBM 1PA, Operational, Installation, And Maintenance Manual

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Chapter 1. Introducing the IBM 7299 Multiplexer, Express
Hub, and Entry Hub for AS/400
The 7299s let you connect 5250-type devices to an AS/400, a System/38, or a
System/36 host using twisted-pair cabling. Twisted pair cabling costs about
one-fifth as much as twinaxial cabling, and it can be used for other voice and data
connections. Using twisted-pair cabling also provides a transition for migrating to
Ethernet** and Token Ring LANs.
The 7299 Multiplexer (Mux) works the same as the 6299 family with the following
additional functions:
Ÿ
Support for the AS/400 Advanced Workstation Controller's 2X data rate to all
ports at 2Mbps. For details, see “The 5250 Express Data Stream” on
page 1-3. The AS/400 Optimized Mode is passed unchanged by the 7299
Multiplexer.
Ÿ
Support for the AS/400 Advanced Workstation Controller's split polling feature.
This feature allows the workstation controller (WSC) to service ports two times
as often as previous WSCs. The 6299 supports only a single polling group of 8
ports whereas the 7299 Multiplexer supports two polling groups on the same
fiber.
Note: This permits choosing up to four ports from two different twinax WSC
polling groups (among WSC adapters from a single host or among WSC
adapters from two hosts).
Ÿ
Ring Distribution for remote terminals. The 6299 performs only a point-to-point
distribution (from the host to a single remote location). The 7299 Host
Multiplexer provides all input ports and all their addresses at each of up to
three Device Multiplexers. See Figure 2-3 on page 2-6. All seven addresses
from each port are available at each Device Multiplexer location. Address
conflicts are handled in the same way conflicts are found and resolved on
twinax.
You can connect the 7299 Multiplexer to the Host:
Ÿ
Directly to the WSC by using the Host-to-Multiplexer cable (P/N 05J4550) and
up to two additional extension cables (P/N 21F0075). Using these cables
allows the Multiplexer to be located between 30 to 80 feet from the host.
Ÿ
Directly to one or two 5X94 remote controllers with the DB9 Y-cable (P/N
05J4533) and the Host-to-Multiplexer cable (P/N 05J4550). You may use up to
two extension cables (P/N 21F0075). Using these cables allows the Multiplexer
to be located between 30 to 80 feet from the host.
Ÿ
Through one or more twinax breakout boxes and baluns. You can choose up
to four ports from two different twinax WSC polling groups (among WSC
adapters from a single host or among WSC adapters from two hosts).
The IBM 7299 Express Products for AS/400 products include both passive and
active hubs. All the 7299 hubs split the signal from a twinax workstation controller
port and distribute it among the attached devices.
The 7299 provides 1 Mbps mode mode support for legacy 1 Mbps mode devices
and workstation controllers.
Chapter 1. Introducing the IBM 7299 Multiplexer, Express Hub, and Entry Hub for AS/400
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