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23

16-PORT TYPE 3 MAU

3.1.3  A

DJUSTED

R

ING

L

ENGTH

In networks that use more than one MAU, adjusted ring length (ARL) is the
total length of the cable connecting MAUs (the main ring) minus the shortest
inter-MAU cable.  Patch cables less than three feet in length are not included
in this calculation.  See the diagram below.

MAU

100 feet

150 feet

50 feet

MAU

MAU

(Subtract length of

shortest section

Attaching

Device

Attaching

Device

150 + 100 = 300 ft. (total main ring length)

300 - 50 = 250 ft. (adjusted ring lenght)

Figure 3-5.  Adjusted ring length.

The use of ARL is intended to simplify network planning. The length of the

longest lobe in the network is added to ARL, and the sum is compared to a
chart later in this chapter to determine maximum ring size. See 

Section 3.2,

Calculating Distances

.

3.1.4  L

OBE

L

ENGTH

The distance between each attaching device and its MAU is very important in
network planning. Maximum lobe lengths are a function of several factors,
and they will vary depending on how the network is configured. See 

Section

3.2, Calculating Distances

.

Summary of Contents for LT2060A

Page 1: ... technical support 24 hours a day 7 days a week Call 724 746 5500 or fax 724 746 0746 Mail order Black Box Corporation 1000 Park Drive Lawrence PA 15055 1018 Web site www blackbox com E mail info blackbox com APRIL 1997 LT2060A 16 Port Type 3 MAU RI RO RESET 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 16 Port Type 3 MAU ...

Page 2: ...operated in a commercial environment Operation of this equipment in a residential area is likely to cause interference in which case the user at his own expense will be required to take whatever measures may be necessary to correct the interference Changes or modifications not expressly approved by the party responsible for compliance could void the user s authority to operate the equipment This d...

Page 3: ...camente con carritos o pedestales que sean recomendados por el fabricante 7 El aparato eléctrico debe ser montado a la pared o al techo sólo como sea recomendado por el fabricante 8 Servicio El usuario no debe intentar dar servicio al equipo eléctrico más allá a lo descrito en las instrucciones de operación Todo otro servicio deberá ser referido a personal de servicio calificado 9 El aparato eléct...

Page 4: ...ado únicamente de acuerdo a las recomendaciones del fabricante 15 En caso de existir una antena externa deberá ser localizada lejos de las lineas de energia 16 El cable de corriente deberá ser desconectado del cuando el equipo no sea usado por un largo periodo de tiempo 17 Cuidado debe ser tomado de tal manera que objectos liquidos no sean derramados sobre la cubierta u orificios de ventilación 18...

Page 5: ...6 16 PORT TYPE 3 MAU TRADEMARKS IBM and AS 400 are registered trademarks of IBM Corporation All applied for and registered trademarks are the property of their respective owners ...

Page 6: ...ction 14 2 1 Token Ring Background 14 2 2 MAUs 17 3 Installation 18 3 1 Installation Background 18 3 1 1 Main Ring 18 3 1 2 Backup Path 20 3 1 3 Adjusted Ring Length 23 3 1 4 Lobe Length 23 3 1 5 Cable Type 24 3 1 6 Repeaters 24 3 1 7 Bridges 24 3 1 8 16 Mbps Token Rings 24 3 2 Calculating Distances 25 3 3 Distance Charts 27 3 4 Completing the Installation 32 3 4 1 Station Port Initialization 33 3...

Page 7: ...ors Battery for operation of port reset feature 3V lithium Duracell 1 2 AA SE or equivalent Field replaceable Operating Temperature 32 to 131 F 0 to 55 C Humidity Up to 95 non condensing Size 1 72 H x 17 25 W x 6 D 4 37 x 43 82 x 15 24 cm Weight 23 25 lb 1 46 kg This MAU has female RJ 45 shielded lobe connectors The connectors labeled Ring In and Ring Out are for attachment to the token ring The M...

Page 8: ...To operate the port reset feature press the Reset button When the LED above the Reset button lights it indicates that the battery is operable and that all inactive station ports will be aligned Ports with active stations on them will not be disturbed 1 2 RJ 45 Connectors The diagram below shows the transmit and receive pins in the female RJ 45 connectors RJ 45 Ring Out Lobe ie Station Connectors T...

Page 9: ...MPORTANT NOTE The cable used with your MAUs must have at least two twisted pairs of wire for data no matter what cable type is used This means a minimum of four separate wires whether or not you will use all four The cable must be wired straight through as shown in Figure 1 2 Do not connect transmit and receive wires in the same twisted pair of wires A B C D A B C D D A C B A B C and D represent t...

Page 10: ... in all inactive station ports so they are ready for operation This feature is powered by a replaceable battery To operate the port reset feature press the Reset button When the LED above the Reset button lights it indicates that the battery is operable and that all inactive station ports will be aligned Ports with active stations on them will not be disturbed 1 3 Cable Specifications 1 3 1 CATEGO...

Page 11: ...5 to 114 ohms at 772 kHz 84 to 113 ohms at 1000 kHz Maximum attenuation per 1000 feet 4 00 dB at 256 kHz 5 66 dB at 512 kHz 6 73 dB at 772 kHz 8 00 dB at 1000 kHz NOTE Commonly available consumer telephone cable sometimes called flat cable or silver satin should not be used This type of cable can drastically reduce the cable lengths possible in your network Exceptions to this are the patch cables ...

Page 12: ...al Interference Because Type 3 cable is unshielded care must be taken to avoid areas of electrical disturbance Some examples of sources of electrical disturbance are Fluorescent lights Power cables Electric motors Radio transmitters ...

Page 13: ...aring and peer to peer communications can improve user productivity within office environments The IBM Token Ring Network is a network system that allows interconnection of PCs and their associated devices in addition to allowing interconnection of PCs to minicomputers and mainframes The IBM Token Ring Network conforms to the IEEE 802 5 Token Ring Access Method standard Other token ring networks c...

Page 14: ...in data path of the ring In this way a problem occurring on the device side of the MAU will not usually affect the operation of the entire ring Also concentrating station connections in a small area aids troubleshooting A PC interfaces the network through the use of a token ring adapter which is a card installed in the PC When the adapter receives the token and has no data to transmit it electrica...

Page 15: ...MAU When the MAU senses this current a relay is opened and the attaching device is connected to the ring The network consists of the adapters the MAUs and the cabling that connects them One or more of the devices for example a powerful PC or an AS 400 are typically designated as file servers other workstations can then access or download files from the servers The token ring can use communications...

Page 16: ...work Inexpensive Type 3 cable may be used in addition to Types 1 and 2 cable You may also use UTP or STP 100 ohm Category 5 cable RJ 45 connectors Diagnostic LEDs Terminal lobe ports on MAU are initialized with a front panel pushbutton eliminating the need for a separate port setup tool ...

Page 17: ...hing MAUs to devices Number of wiring closets Verifying that the proper type of cable is used see Section 1 3 Cable Specifications Safeguarding against electrical interference especially when Type 3 cable is used A copy of the floor plans of the buildings that will use the token ring network will help greatly in planning the installation NOTE When using Type 3 cable with 4 Mbps token rings Black B...

Page 18: ...in ring is critical to proper network operation The main ring does not include the cable from MAUs to their attaching devices these cables are called lobes Figure 3 1 Main Ring If there is only one MAU for the entire ring the main ring can be considered to have no length for installation purposes Main Ring Lobe Signal Direction MAU 3 Attaching Devices MAU 1 MAU 2 ...

Page 19: ... to enable the network to continue to operate while a problem such as a faulty cable or MAU is being repaired For example if a breakdown occurs in the cable between MAU 1 and MAU 2 as in Figure 9 the rest of the ring will remain in operation if the backup path is used Note that when the backup path is used it becomes part of the main ring and its length must be included in the main ring length In ...

Page 20: ... transmitted so far that attenuation makes it unreadable When the network is first activated at the start of a business day it may consist of only one active attaching device connected to the main ring For this example assume that the attaching device is on the longest lobe MAU 100 feet 50 feet 150 feet 50 feet x 2 Longest Lobe Attaching Device Actual transmission path distance 50 x 2 150 50 100 4...

Page 21: ...ssible transmission path occurs when the backup path is being used with the shortest section of cable removed and when the station on the longest lobe is the only active station on the network The longest possible distance must be assumed when planning the network MAU 100 feet x 2 Shortest Cable Removed 150 feet x 2 50 feet x 2 Longest Lobe Attaching Device Actual transmission path distance 50 x 2...

Page 22: ...vice 150 100 300 ft total main ring length 300 50 250 ft adjusted ring lenght Figure 3 5 Adjusted ring length The use of ARL is intended to simplify network planning The length of the longest lobe in the network is added to ARL and the sum is compared to a chart later in this chapter to determine maximum ring size See Section 3 2 Calculating Distances 3 1 4 LOBE LENGTH The distance between each at...

Page 23: ...5 m on Type 3 cable and up to 2400 feet 731 m on Types 1 or 2 cable Fiberoptic repeaters can transmit the network signal up to 10 000 feet 3 km on fiberoptic cable If repeaters will be used it will affect the installation of MAUs Follow the installation instructions given in the manuals for your repeaters 3 1 7 BRIDGES Bridges can help organize the rings of a network and enhance performance from t...

Page 24: ...n the ring must be less than or equal to the distance given for your network s configuration in one of the tables in Figures 14 through 19 Expressed as a formula this is ARL longest lobe maximum distance for your configuration from the appropriate table NOTE The distances given in the tables for Type 3 cable will require Black Box media filters part number LT057 between the adapters and the networ...

Page 25: ...ts length is insignificant and it is assumed that if it goes bad it will be replaced instead of looping the ring onto the backup path The ARL is 95 feet total main ring length minus the shortest segment 125 30 The maximum distance for this network is 435 feet as taken from the chart in Table 3 1 24 gauge Type 3 cable four MAUs and three wiring closets This means that the maximum lobe length allowe...

Page 26: ...following pages are used with the distance formula given in Section 3 2 Calculating Distances Table 3 1 4 Mbps Distance Chart for Type 3 Cable Distances are given in feet meters Number Number of Wiring Closets of MAUs 1 2 3 4 5 19 Gauge 1 600 183 2 585 181 575 175 3 570 174 560 171 550 168 4 555 169 545 166 535 163 525 160 5 540 165 530 162 520 158 510 155 500 152 6 525 160 515 157 505 154 495 151...

Page 27: ... 2 535 163 525 160 3 520 158 510 155 500 152 4 505 154 495 151 485 148 475 145 5 490 149 480 146 470 143 460 140 450 137 6 475 145 465 142 455 139 445 136 435 133 7 460 140 450 137 440 134 430 131 420 128 8 445 136 435 133 425 130 415 126 405 123 24 Gauge 1 500 152 2 485 148 475 145 3 470 143 460 140 450 137 4 455 139 445 136 435 133 425 130 5 440 134 430 131 420 128 410 125 400 122 ...

Page 28: ...15 126 405 123 395 121 385 117 7 410 125 400 122 390 119 380 116 370 113 8 395 120 385 117 375 114 365 111 355 108 26 Gauge 1 470 143 2 455 139 445 136 3 440 134 430 131 420 128 4 425 130 415 126 405 123 395 121 5 410 125 400 122 390 119 380 116 370 113 6 395 120 385 117 375 114 365 111 355 108 7 380 116 370 113 360 110 350 107 340 104 8 365 111 355 108 345 105 335 102 325 99 ...

Page 29: ...19 Gauge 1 221 67 2 215 66 212 65 3 210 64 207 63 204 62 4 205 62 202 62 199 61 196 60 5 200 61 197 60 194 59 191 58 188 57 6 195 59 192 59 189 58 186 57 183 56 7 190 58 187 57 184 56 181 55 178 54 8 184 56 182 55 179 55 176 54 173 53 22 Gauge 1 215 66 2 210 64 207 63 3 205 62 202 62 200 61 4 200 61 197 59 195 59 191 58 5 195 59 192 59 189 58 187 57 183 56 ...

Page 30: ... 58 187 57 184 56 182 55 179 55 7 184 56 182 55 180 55 176 54 174 53 8 180 55 177 54 174 53 172 52 169 52 24 Gauge 1 210 64 2 205 62 202 62 3 200 61 197 60 195 59 4 195 59 193 59 189 58 187 57 5 190 58 188 57 184 56 182 55 179 55 6 186 56 183 55 180 55 176 54 174 53 7 181 55 178 54 174 53 172 52 169 52 8 176 54 173 53 170 52 167 51 165 50 26 Gauge 1 189 58 2 184 56 182 55 ...

Page 31: ...istances are given in feet meters Number Number of Wiring Closets of MAUs 1 2 3 4 5 3 180 55 178 54 175 53 4 176 54 173 53 171 52 168 51 5 172 52 169 52 166 51 164 50 161 49 6 167 51 165 50 162 49 160 49 157 48 7 162 49 160 49 158 48 155 47 153 47 8 158 48 156 48 153 47 151 46 148 45 ...

Page 32: ... button to reset them The Reset button on the front panel is used to align the relays in the station ports so they are ready for operation This feature is powered by a replaceable battery To operate the port reset feature press the Reset button When the LED above to the Reset button lights it indicates that the battery is operable and that all inactive station ports will be aligned Ports with acti...

Page 33: ...ir associated MAU ports 3 If the ring is not running connect the MAUs to the main ring using the Ring In and Ring Out connectors Ring In receives the cable from the previous MAU Ring Out connects to the cable going to the next MAU Bring up the ring and make sure that the attaching devices are powered on and are set up to request network access If the ring is already operating the new MAUs may be i...

Page 34: ... card is not set up correctly There is a problem in the network itself If this is the case there will probably be trouble elsewhere in the network The building wiring has improper connections If the terminal LED is not on verify that the lobe is not too long Proper lobe lengths are covered in Chapter 3 Installation If the lobe cable is the proper length verify that its condition is good and that i...

Page 35: ...h if part of the ring is inoperative See Section 3 1 2 category 5 cable defined by the EIA TIA for data applications up to 100 Mbps See Section 1 3 1 frame when an attaching device appends data to the network token the token becomes a frame lobe the cable between an MAU and an attaching device loopback cable used with RJ 45 equipped MAUs when there is only one MAU for a ring It connects ring in to...

Page 36: ...sted pair cabling See Section 1 3 Cable Specifications type 2 same as type 1 except that the cable includes several pairs of ordinary telephone wire enclosed in the same outer sheath as the shielded data cable See Section 1 3 Cable Specifications type 3 the IBM Cabling System term for unshielded telephone twisted pair wire See Section 1 3 Cable Specifications ...

Page 37: ...1000 Park Drive Lawrence PA 15055 1018 724 746 5500 Fax 724 746 0746 Copyright 1997 Black Box Corporation All rights reserved ...

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