MR-2000C
MULTI-PORT REPEATER
USER’S GUIDE
cvrBook Page 1 Friday, January 26, 1996 2:07 PM
NOTICE
Cabletron Systems reserves the right to make changes in specifications and other information contained in
this document without prior notice. The reader should in all cases consult Cabletron Systems to determine
whether any such changes have been made.
The hardware, firmware, or software described in this manual is subject to change without notice.
IN NO EVENT SHALL CABLETRON SYSTEMS BE LIABLE FOR ANY INCIDEN-
TAL, INDIRECT, SPECIAL, OR CONSEQUENTIAL DAMAGES WHATSOEVER (INCLUDING
BUT NOT LIMITED TO, LOST PROFITS) ARISING OUT OF OR RELATED TO THIS MANUAL OR
THE INFORMATION CONTAINED IN IT, EVEN IF CABLETRON SYSTEMS HAS BEEN AD-
VISED OF, KNOWN, OR SHOULD HAVE KNOWN, THE POSSIBILITY OF SUCH DAMAGES.
© Copyright August 1988 by
Cabletron Systems Inc.
P.O. Box 6257, E. Rochester, NH 03867-6257
All Rights Reserved
Printed in the United States of America
Order number: 9030014-01 August 88
LAN-MD
and
LANVIEW
are trademarks of Cabletron Systems Inc.
TABLE OF CONTENTS
SECTION PAGE
SECTION 1 - INTRODUCTION
1.1 INTRODUCTION ..............................................................................................................1-1
1.2 USING THIS MANUAL....................................................................................................1-1
1.3 SPECIFICATIONS.............................................................................................................1-1
1.4 RELATED USER MANUALS ..........................................................................................1-6
SECTION 2 - PREPARATION FOR OPERATION
2.1 INTRODUCTION ..............................................................................................................2-1
2.2 NETWORK DESIGN GUIDELINES................................................................................2-1
2.3 SITE SELECTION GUIDELINES.....................................................................................2-2
2.4 SET-UP FOR OPERATION...............................................................................................2-2
SECTION 3 - TESTING AND LANVIEW
3.1 INTRODUCTION ..............................................................................................................3-1
3.2 INSTALLATION CHECK-OUT .......................................................................................3-1
3.3 USING LANVIEW.............................................................................................................3-2
WARRANTY AND SERVICE
Cabletron Systems warrants that the MR-2000C shall be free from defect in material and workmanship for a period of one (1) year from the
date of initial shipment by Cabletron Systems. The foregoing warranty does not apply to any products which have been subjected to misuse,
neglect, accident, or modification.
If found to be defective by Cabletron Systems within the terms of this warranty, Cabletron Systems’ sole obligation shall be to repair or re-
place, at Cabletron Systems’ option, the defective product and carry out the unexpired term of the warranty which was applicable to the de-
fective product. All replaced materials become the property of Cabletron Systems.
As a condition of this warranty, customers must (1) obtain a Cabletron Systems Return Material Authorization (RMA) number and shipping
instructions, (2) return the product (or approved subassemblies), transportation prepaid and insured to Cabletron Systems’ designated repair
facility, and (3) include a written description of the claimed defect.
If Cabletron Systems determines that the product is not defective within the terms of this warranty, the customer shall pay all costs of handling
and return postage; otherwise normal transportation charges for the return to Customer shall be paid by Cabletron Systems within the United
States only. This warranty outside of the United States excludes all costs of shipping, Customs clearance, and other related charges.
Except for the express warranties stated above, Cabletron Systems disclaims all warranties on products including all implied warranties of
merchantability and fitness; and the stated express warranties are in lieu of all obligations or liabilities on the part of Cabletron Systems.
SECTION 1
INTRODUCTION
1.1 INTRODUCTION.
The Cabletron Systems MR-2000C Multiport Repeater is an easy to install meth-
od of connecting two thin-net cable segments to a thick or thin-net cable segment, or to a fiber optic link
segment. This repeater fully conforms to IEEE 802.3 specifications and provides the flexibility to connect
networks using Ethernet Version 1, Version 2, and/or IEEE 802.3 equipment.
These segments are connected by first attaching a BNC tee connector to the BNC port located on the rear
of the repeater. The BNC tee connector allows two thin-net segments, that can be 185 meters in combined
length, to be connected to the repeater. The thin or thick-net cable segment, or the fiber optic link segment,
is then connected to the repeater by attaching an external transceiver to that segment. An attachment unit
interface (AUI) cable is then used to connect the external transceiver to an AUI port, also located on the
rear of the repeater. All three segments are linked when they are attached to the repeater. The MR-2000C
will transmit re-timed data packets, regenerate preambles, extend collision fragments, automatically par-
tition problem segments, and automatically reconnect non-problem segments.
The MR-2000C also incorporates Cabletron Systems’ LANVIEW™ diagnostic system. Should a problem
arise, power failures, collisions, cable faults and many other problems can be diagnosed rapidly by using
a series of LEDs.
1.2 USING THIS MANUAL.
This manual provides instructions for Installing, Testing, and Operating
the Cabletron Systems MR-2000C Multiport Repeater.
This manual assumes that the user has a general working knowledge of Ethernet or IEEE 802.3 type data
communications networks and their physical layer components.
If additional support is needed related to the Cabletron Systems MR-2000C, or if you have any comments,
improvements, suggestions, or questions relating to this manual, feel free to contact Cabletron Systems
Technical Support at:
Cabletron Systems
P.O. Box 6257
E. Rochester, NH 03867-6257
Phone: (603) 332-9400
1.3 SPECIFICATIONS.
Listed below are the specifications for the Cabletron Systems MR-2000C Mul-
tiport Repeater.
NOTE
Cabletron Systems reserves the right to change these specifications
at any time without notice.
GENERAL
Delay Times: (Port 1 Into Port 2 out)
Start of Packet: 1450 ns max.
Collision to JAM: 1550 ns max.
Delay Times: (Port 2 Into Port 1 out)
Start of Packet: 1150 ns max.
Collision to JAM: 1000 ns max.
Preamble:
Input: Minimum of 40 bits to a maximum of 64 bits re-
quired.
Output: 64 bits min. (last 2 bits are 1, 1).
JAM Output: A pattern of 1, 0 is sent to the other segment if a
collision occurs on one of the segments.
Minimum Packet Repeated: 96 bits including preamble (Packet fragments are
extended using the JAM [1, 0] data pattern).
FAULT Protection: Each segment will disconnect itself from the other
segments if 32 consecutive collisions occur, or if
the collision detector of a segment is on for longer
than approximately 2.4 ms. This FAULT protec-
tion will reset automatically after one packet is
transmitted onto the FAULT protected segment
without causing a collision.
FRONT PANEL INDICATORS
PWR
Indicates that the repeater is receiving power.
XCVR PWR
Indicates that the repeater is providing power to the
transceiver connected to the repeater.
JAM
Indicates the MR-2000C is propagating a collision
on one segment to the other segment connected to
the repeater.
FRONT PANEL INDICATORS (CONT)
NOTE
<wcn>There is one
RECEIVE
,
COLLISION
, and
FAULT
LED
for each segment. The LEDs for
RECEIVE
and
COLLISION
are
pulse stretched for increased viewing effect.
RECEIVE
Indicates that the repeater is receiving a data packet
on that segment.
COLLISION
Indicates that a collision is occurring on that seg-
ment.
FAULT
Indicates that the MR-2000C has electrically dis-
connected that segment from the network because
of a cable fault or 32 consecutive collisions.
BNC INTERFACE (PORT 1)
Type: BNC receptacle, with gold center contacts, for use
with BNC type plugs and RG-58A/U thin-net ca-
ble.
Internal Transceiver: Cabletron Systems TMS-3 Transceiver.
Specification for the TMS-3 are available upon re-
quest.
AUI INTERFACE (PORT 2)
Parameter Typical Worst
Value Case
Frequency Range:4 to 20 MHz 5 to 15 MHz
RX and CP Pair Input Impedance
Differential: 78 ohms 76 to 80 ohms
Common-mode: Greater than 20.0 ohms
AUI INTERFACE (PORT 2) (CONT)
Parameter Typical Worst
Value Case
Common-mode Voltage Range
at RX or CP Pair:0 to 30 V 0 to 5 V
Input Sensitivity at RX or CP
Pair: +/-100 mV +/-75 to +/-150 mV
Waveform Symmetry TX Pair:+/-0.5 ns +/-1.0 ns
Output Voltage Into 78 Ohms
TX Pair:+/-900 mV +/-55 mV
Interface Connector
Type: 15 position D type receptacle.
Pin 1
Logic Ref
. Pin 9 Collision -
2 Collision + 10 Transmit -
3 Transmit + 11
Logic Ref
.
4
Logic Ref
. 12 Receive -
5 Receive + 13 Power (+12 Vdc)
6 Power return 14
Logic Ref
.
7 No Connection 15 No Connection
8
Logic Ref.
Connector Shell: Protective Ground
POWER SUPPLY REQUIREMENTS
Parameter Typical Worst
Value Case
Input Voltage Vac 47-63 Hz
NOTE
Input voltage is user selectable. The MR-2000C is shipped ready for
use with 120 volt AC input.
120 Volts Selected: .3 A @ 120 V .5 A @ 90 to 130 V
220 Volts Selected: .15 A @ 220 V .25 A @ 180 to 250 V
Input Current: 0.5 A 1.0 A
POWER SUPPLY REQUIREMENTS (CONT)
Parameter Typical Worst
Value Case
Output Voltage: 12 Vdc 11.5 to 15.5 Vdc
Overload Protection
Input: (2) 3AG 3 amp fuses in series with both primary inputs.
Output: (2) 3AG 1 amp fuses.
ENVIRONMENTAL REQUIREMENTS
Operating Temperature: +5
°
to +40
°
C
Non-operating Temperature: -30
°
to +90
°
C
Operating Humidity: 5 to 95% (non-condensing)
SAFETY
WARNING
It is the responsibility of the person who sells the system to which
the MR-2000C will be a part of to ensure that the total system meets
allowed limits of conducted and radiated emissions.
Designed in accordance with UL478, UL910, NEC 725-2(b), CSA, IEC, TUV, VDE class A.
Meets FCC part 15, Subparagraph J, Class A limits.
SERVICE
MTBF (MHBK-217D):> 50,000 hrs. projected
MTTR:<0.5 hrs.
PHYSICAL
Dimensions:3.2H x 15.0W x 12.4D inches
(8.13 x 38.1 x 31.5 cm)
Weight
Unit: 7 lbs.
Shipping: 8 lbs.
1.4 RELATED USER MANUALS.
The manuals listed below should be used to supplement the proce-
dures and other technical data provided in this manual. The procedures contained in these manuals will
be referenced, rather than repeated, in this manual.
•
UM-FOT-1
Cabletron Systems Fiber Optic Transceiver User’s Manual.
•
UM-ST-500
Cabletron Systems ST-500 Transceiver User’s Manual.
•
UM-TMS-3
Cabletron Systems TMS-3 Transceiver User’s Manual.
•
UM-LAN-MD
Cabletron Systems LAN-MD Portable Ethernet Tester User’s Manual.
•
UM-TDR 5000
Cabletron Systems TDR 5000 Cable Tester User’s Manual.
SECTION 2
PREPARATION FOR OPERATION
2.1 INTRODUCTION.
The MR-2000C Multiport Repeater is designed for quick and easy installation.
No special skills or tools are required to install the repeater on an Ethernet network.
2.2 NETWORK DESIGN GUIDELINES.
The following network design guidelines must be followed
for connecting a MR-2000C Multiport Repeater to the network. If not, unsatisfactory network perfor-
mance may result.
• 50 ohm Ethernet type coaxial cable must be used when making up thick-net cable segments.
• 50 ohm RG-58A/U type coaxial cable must be used when making up thin-net cable segments.
• Each thick-net cable segment that the MR-2000C will be connected to must be no longer than 500
meters (1640 feet) in length.
When making up networks requiring shorter cable runs, Ethernet standard length 23.4 m, 70.2 m, and
117 meter cable sections should be used. These cable sections may be connected together to form a
cable segment by using a barrel connector.
Use of non-standard cable lengths may result in impedance mismatches causing reflections to occur.
These reflections may cause data errors.
• Each thin-net cable segment that will be connected to the BNC port on the MR-2000C must be no longer
than 185 meters (606 feet) in total length.
• Each end of the thick or thin-net cable segment must be connected to a 50 ohm terminator.
• A maximum of 100 transceivers may be attached to a thick-net cable segment, and these transceivers
must be at least 2.5 meters apart throughout the length of the cable.
Transceivers should be placed on the black bands that run along the cable and are marked at 2.5 meter
intervals.
• A maximum of 30 connections may be made to a thin-net cable segment, and these connections must
be at least 0.5 meters apart.
• For safety, only one end of any thick or thin-net segment should be connected to earth ground. Con-
nection to earth ground at more than one point on the segment may allow for the occurrence of danger-
ous ground currents.
The BNC port of the MR-2000C is not connected to earth ground.
• On a thin-net cable segment, the male end of a BNC tee connector is used to directly connect hosts or
the transceiver to the thin-net segment. The female ends of the connector must be connected to another
cable segment or terminator.
• The transceiver to which the MR-2000C will be connected to must meet IEEE 802.3 standards and not
have the SQE test function enabled.
• The AUI cable connecting the MR-2000C to the transceiver on the network must be IEEE 802.3 type
cable and must not exceed 50 meters in length.
• From its source address to its destination address, a data packet may pass through four repeaters.
2.3 SITE SELECTION GUIDELINES.
The following guidelines must be followed to select a site for
the MR-2000C Multiport Repeater. If not, unsatisfactory network performance may result.
• An unrestricted free surface area of 21 inches wide, 18 inches deep and 6 inches high is needed.
• A USA standard 3 prong power receptacle must be located within 7 feet of the site.
• If a shelving unit is to be used, it must be able to support 30 pounds of static weight.
• The temperature of the location must be maintained between 5
°
and 40
°
C. Temperature changes greater
than 10
°
C per hour must not occur.
2.4 SET-UP FOR OPERATION.
Set-up the MR-2000C Multiport Repeater for operation as follows:
1. Unpack the MR-2000C as follows:
a. Remove the repeater from shipping box.
b. Slide the two foam end caps off the repeater.
c. Remove the repeater from protective plastic bag and set the repeater aside in a safe place.
d. Remove the plastic bag containing the accessory package and check that all items listed below are
in the bag:
• One 8 foot USA power cord.
• One cable support bracket.
• Two 8-32 x .375 in. screws.
• Three 6 in. cable ties.
NOTE
Save the shipping box and materials in the event the repeater has to
be reshipped.
2. Using the two 8-32 screws (3, Fig. 2-1), attach the cable support (2) to the repeater (1).
3. Place the repeater on the selected site.
Be sure that the site meets the guidelines listed in Section 2.3.
CAUTION
Ensure that the external transceiver to which the MR-2000C will be
connected does not have the signal quality error (SQE or “heart-
beat”) test function enabled. The MR-2000C will not operate if the
transceiver has the SQE test function enabled, and the network will
be unusable. Refer to the applicable transceiver manual.
4. Attach a transceiver (12, Fig. 2-2) to the segment that will be connected to AUI port 2. Refer to the
applicable transceiver manual.
5. Attach an AUI cable (11), no longer than 50 meters in length, to the transceiver connected in step 4.
6. Connect the AUI cable to AUI port 2 (10) located on the backside of the repeater.
7. Attach a BNC tee connector to BNC port 1.
CAUTION
Two thin or thick-net cable segments (5,7, View B) may be connect-
ed to the BNC tee connector (6) attached to the BNC port. However,
the combined length of the two thick or thin-net cable segments must
not exceed 500 meters or 185 meters respectively.
If only one thick or thin-net segment (2, View A) is to be connected
to the BNC tee connector (3), a 50 ohm terminator (4) must be con-
nected to the open end of the connector.
NOTE
If a thick-net cable segment is to be attached to the tee connector, a
thick to thin-net adapter must be attached to the connector.
8. Attach the cable segment(s) to the BNC tee connector.
9. Plug the power cord (8) into the power receptacle (9) located on the backside of the repeater.
10. Plug the power cord into a wall receptacle.
The
PWR
LED, indicating that the repeater is receiving power, and the
XCVR PWR
LED, indicating
that the repeater is providing power to the transceiver connected to the repeater, should be lit.
11. Using the cable ties provided, strain relief all cables and the power cord to the cable support on the
backside of the repeater.
The MR-2000C is now ready for operation. It is recommended that the installation be tested prior to trans-
mitting data. Refer to
Section 3.2 - INSTALLATION CHECK-OUT
.
SECTION 3
TESTING AND LANVIEW
3.1 INTRODUCTION.
This section lists procedures to test the MR-2000C Multiport Repeater after it
has been connected to the network. A description of LANVIEW and its function in troubleshooting phys-
ical layer network problems is also given.
3.2 INSTALLATION CHECK-OUT.
This section contains procedures to test the MR-2000C Multiport
Repeater after it has been installed to ensure that the physical layer of the network is operating properly.
Two Ethernet node testers that will generate valid data packets, such as Cabletron Systems’ LAN-MD, are
required for this procedure.
NOTE
This procedure should be performed only after testing each segment
with a TDR, such as Cabletron Systems’ TDR 5000, to verify that
the cable lengths, impedance and terminations are within IEEE
802.3 specification limits.
NOTE
For the purposes of this procedure, it is assumed that two
Cabletron Systems LAN-MDs are being used. For details on the
LAN-MD, refer to the LAN-MD User’s Manual.
1. Using a transceiver and an AUI cable, connect a LAN-MD to either of the segments connected to the
repeater.
2. Select and run test
6 - SERVER
.
If this test passes, leave the LAN-MD running.
This LAN-MD now acts as a
SERVER
unit and will act as a packet echoer when used with another
LAN-MD.
3. Using a transceiver and an AUI cable, connect another LAN-MD to the other segment connected to
the repeater.
4. Select and run test
4 - NODE
on the LAN-MD connected in step 3.
Check that this test passes.
At least 100 packets should be sent and received with no errors. The packets will be received from and
sent back to the LAN-MD acting as the
SERVER
.
5. Select and run test
3 - ON NET XCVR
on both LAN-MDs.
Check that this test passes.
6. Remove a terminator from one of the segments connected to the MR-2000C.
The
FAULT
LED for that segment should light on the MR-2000C.
7. Reconnect the terminator removed in step 6.
8. Check that the
FAULT
LED for that segment goes off.
9. Repeat steps 6 through 8 for each segment connected to the MR-2000C.
When the MR-2000C Multiport Repeater has successfully completed these tests, the repeater is ready for
normal operation. If any failures were noted, please contact Cabletron Systems Technical Support.
3.3 USING LANVIEW
. The MR-2000C Multiport Repeater uses Cabletron Systems’ built-in visual di-
agnostic and status monitoring system, LANVIEW. Rather than using a network monitor, a network trou-
bleshooter can quickly scan the LANVIEW LEDs to observe network status or to diagnose network
problems to determine which node or segment is faulty.
The following discusses the function and the purpose of each LANVIEW LED on the MR-2000C. Refer
to Figure 3-2.
Power
(PWR)
LED
When lit, this LED indicates that the MR-2000C is receiving power. If this LED is not lit, the problem
may be with the input power, or the MR-2000C.
Transceiver Power
(XCVR PWR)
LED
When lit, this LED indicates that the MR-2000C is providing power to the external transceiver con-
nected to the MR-2000C. If this LED is not lit, power is not being provided to the transceiver and the
problem may be in the MR-2000C.
Jam
(JAM)
LED
This LED normally flashes on and off to indicate that the MR-2000C is propagating a collision from
the segment on which the collision is occurring to the other segments connected to the repeater. When
this LED flashes, a pattern of 1,0 is sent to each segment to indicate that a collision is occurring on one
of the segments. What will be observed is that the
COLLISION
LED for one segment will flash, in-
dicating a collision, causing the
JAM
LED to flash.
NOTE
There is one
RECEIVE
,
COLLISION
, and
FAULT
LED for each
port on the MR-2000C.
Receive
(RECEIVE)
LED
This LED normally flashes on and off to indicate that the MR-2000C is repeating the data packet being
received from that segment. The rate at which the LED flashes will increase as network activity in-
creases.
Collision
(COLLISION)
LED
This LED normally flashes on and off to indicate that a collision is occurring on the indicated segment.
The rate at which the LED flashes will increase as network activity increases since more collisions are
likely to occur.
Fault
(FAULT) LED
When the FAULT LED is lit, this indicates that the MR-2000C has disconnected that segment from
the network because 32 consecutive collisions have occurred on the segment, or because the collision
detector was on for longer than approximately 2.4 ms. The FAULT LED will go out after one packet
is transmitted onto the faulted segment without causing a collision.
/
