2 91.4
m
(300 ft) 3 83.8m
(275 ft) 4 76.0m
(250 ft) 5 68.5m
(225 ft) 6 68.5m
(225 ft) 7 61.0m
(200 ft) 8 61.0m
(200 ft)Figure 52. Length of a Single Segment Daisy-Chain
In any chain like the example illustrated in Figure 50 on page 116, the
workstation at one end must have a terminator plug and the station at the other end must have a wrap plug.
The adapter card ROM contains self-test diagnostics that are run when the adapter is powered on. These diagnostics help a user to identify adapter failures without a diagnostic diskette or problem determination manuals.
5.3.1.2 IBM 5173 PC Network Baseband Extender
118 LAN Concepts
The IBM 5173 PC Network Baseband Extender is used to expand the IBM PC Network Baseband from eight to eighty nodes. The PC Network Baseband Extender has ten ports, each able to support a chain of maximum eight LAN stations. Each chain attached to the PC Network Baseband Extender has a maximum length of 121.92 m (400 ft). This distance is measured from the extender to the last workstation in the chain.
The IBM 5173 PC Network Baseband Extender is designed for continuous, unattended operation, therefore it does not have an On/Off switch. There are also no option switches or jumpers. The PC Network Baseband Extender has one indicator light which is illuminated when the power is on. The indicator can either be red or green, depending on whether an error was detected by the self-test circuitry. The self-test function is initiated by depressing a button on the front panel.
The PC Network Baseband Extender contains a 12 watt universal power supply.
It has ten "IN" ports on the front panel for connecting chains of PCs to the extender, and two "OUT" ports as shown in Figure 51 on page 117. A wrap plug must be inserted in one of the OUT ports and a terminator plug in the other.
These two ports are identical. Either plug can be connected to either port. A terminator plug must also be inserted into the adapter card of the last workstation of each chain attached to the extender.
Cabling is not supplied with the extender, nor with the PC Network Baseband Adapter cards, but must be ordered separately.
5.3.1.3 PC Network Baseband Cabling and Accessories
The IBM PC Network Baseband uses twisted pair wiring for interconnecting workstations. Three adapter cables are offered to provide connector
compatibility with different types of building wiring. Each cable connects to the workstation adapter with a modular telephone jack (J11). The other end
provides either another modular jack or a different connector type to support daisy chaining of workstations, or connection wall jacks or sockets.
The IBM PC Network Baseband Adapter Cable (1501229) is shielded twisted pair cable with modular telephone connectors at each end. It is designed to serially connect the IBM PC Network Baseband Adapter or the IBM PC Network Baseband Adapter/ A to other workstations in a daisy-chain fashion, or to connect a workstation to the IBM 5173 PC Network Baseband Extender.
The IBM PC Network Baseband General Purpose Cable (1501228) is a shielded twisted pair cable connecting an IBM PC Network Baseband Adapter or IBM PC Network Baseband Adapter/ A to a non-modular telephone socket. It has the modular connector on one end while the other end is made for the older screw terminal blocks.
The IBM Cabling System PC Network Baseband Cable (150227) is a shielded twisted pair cable connecting the IBM PC Network Baseband Adapter, IBM PC Network Baseband Adapter/A, or the IBM 5173 PC Network Baseband Extender (with a modular telephone connector) to the data connector wall jack or 'data connector distribution panel when using the IBM Cabling System.
Each baseband cable is 7.6 m (25 ft) in length. Several of these cables can be joined together to obtain cable lengths greater than 7.6 meters, or users can make their own cables to the lengths they require. With care to prevent electromagnetic interference, unshielded twisted pair wire, meeting the IBM Cabling System Type 3 specifications, may also be applied.
Tne IBM PC Network Baseband Extender Rack Mount Kit (1501226) attaches to the IBM 5173 PC Network Baseband Extender to allow it to be rack mounted in a standard 19 inch rack.
5.3.2 PC Network Baseband Interfaces
5.3.2.1 Medium Access Control support
The IBM PC Network Baseband Adapter and IBM PC Network Baseband
Adapter/A, combined with the adapter support software of the IBM LAN Support Program, implement CSMA/CD access method protocols functional equivalent to the IEEE 802.3. (Refer to "Basic CSMA/CD Concepts" on page 16 for details on the protocol, and to "IBM LAN Support Program" on page 126 for additional information on LAN Support Program.)
5. IBM LA.Ns 119
5.3.2.2 IEEE 802.2 LLC and Higher Layer Support
120 LAN Concepts
The IEEE 802.2 layer is provided by the IBM LAN Support Program V1.10. This program includes the IEEE 802.2 interface, and optionally provides NETBIOS for higher-layer support. The IEEE 802.2 Interface is also required for Advanced Program-to-Program Communication (APPC). See section "IBM LAN Support Program" on page 126 for more details ..
5.4 IBM and Industrial LAN
As explained earlier in "IEEE 802.4, ISO 8802-4" on page 59, the IEEE 802.4 Token-passing bus standard provides the physical layer and MAC sublayer architecture and protocols for a seven-layer Manufacturing Automation Protocol communications network for the manufacturing environment. As described, IBM has stated its intent to provide industrial LAN implementations based upon the final MAP 3.0 specification.
5.4.1 Series/1 and Industrial LAN
The Series/1 in an industrial LAN environment can act as either a communication server or an application server.
5.4.1.1 Communication Server
The Communications Server runs on the Realtime Programming
System/Communications Manager (RPS/CM) operating system. Some of the server functions provided are:
• Availability of the Series/1 as a directory server for the network
• . Network management agent support
• Host control - that is controlof communications with a host system
• Terminal control - that is control of communications with downstream terminals
• Attachment possibilities for System/370 processors.
With a System/370 processor attached to the Series/1, files can be transferred to and from the System/370 using the FTAM (File Transfer, Access and
Management) program. Messaging is also supported using the MMFS (Manufacturing Message Format Standard) support. This provides a way for user-written messaging applications to build and decode standard messages.
Both FTAM and MMFS are MAP 2.1 Application Layer services (see Figure 23 on page 61). MMFS is superseded in MAP 3.0 by the Manufacturing Messaging Specifications (MMS).
The Network Management Agent provides information about the activities in the local MAP Communications Server system to the network manager.
Host control allows a host system, such as TSO, IMS, or CICS to communicate with remote 327x terminals, or applications that simulate 327x terminals on a MAP network. The MAP network is transparent to the host systems.
Terminal control allows users of 327x terminals to communicate with remote host systems across a MAP network.
5.4.1.2 Application Server
The Application Server uses the Series/1 Event Driven
Executive/Communications Facility (EDX/CF) operating system. The application server is used to control intelligent devices and provides the following
functions:
• Network Management Agent services
5. IBM LANs 121
• A subset of directory services
• MMFS support
• FTAM subset
Figure 53 shows an industrial LAN with two Series/1 attachments to the bus using a network interface unit (not shown in the figure).
Host 1
OEMtlJe 1 di ng