Cabletron Systems TRMIM-20R User manual

TRMIM-20R
UTP TOKEN RING
CONCENTRATOR
MEDIA INTERFACE MODULE
INSTALLATION GUIDE
CABLETRON SYSTEMS, P. O. Box 5005, Rochester, NH 03867-5005
The Complete Networking Solution

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 INCIDENTAL, 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 ADVISED OF, KNOWN, OR
SHOULD HAVE KNOWN, THE POSSIBILITY OF SUCH
DAMAGES.
Copyright March 1991 by:
Cabletron Systems, Inc.
P.O. Box 5005, Rochester, NH 03867-5005
All Rights Reserved
Printed in the United States of America
Order Number: 9030275-01 March 1991
TRMIM-20R, TRMIM-10R, TRRMIM-16, TRMIM-12,
Remote LANVIEW/Windows, SPECTRUM, and MMAC are
trademarks of Cabletron Systems, Inc.
LANVIEW is a registered trademark of Cabletron Systems, Inc.
IBM is a registered trademark of International Business Machines
Corporation.
NOTICE
i

FCC NOTICE
This device complies with Part 15 of FCC rules. Operation is subject
to the following two conditions: (1) this device may not cause harmful
interference, and (2) this device must accept any interference
received, including interference that may cause undesired operation.
WARNING: This equipment uses and generates and can radiate
radio frequency energy and if not installed properly and used in
accordance with the instruction manual, may cause interference to
radio communications. It has been tested and found to comply with
the limits for a Class A digital device pursuant to Part 15 of FCC
Rules, which are designed to provide reasonable protection against
such interference 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 steps may be necessary to correct the interference.
If this equipment does cause interference to radio or television, which
can be determined by turning the equipment off and on, the user is
encouraged to try to correct the interference by one or more of the
following measures:
• Re-orient the receiving antenna.
• Relocate the MMAC with respect to the receiving antenna.
• Move the MMAC away from the receiver.
• Plug the MMAC into a different outlet so that the MMAC and
the receiver are on different branch circuits.
If necessary, the user should consult the dealer or an experienced
radio/ television technician for additional suggestions. The user may
find the following booklet prepared by the Federal Communication
Commission helpful:
“How to Identify and Resolve Radio TV Interference Problems”
This booklet is available from the U.S. Government Printing Office,
Washington D.C. 20402 - Stock No. 004-000-00345-4.
FCC NOTICE
ii

CONTENTS
iii
CONTENTS
CHAPTER 1 INTRODUCTION
1.1 Using This Manual ......................................................................1-1
1.2 The TRMIM-20R..........................................................................1-2
1.3 Related Manuals..........................................................................1-4
1.4 Recommended Reading ...............................................................1-5
1.5 Getting Help ................................................................................1-5
CHAPTER 2 INSTALLATION REQUIREMENTS/
SPECIFICATIONS
2.1 Network Requirements ...............................................................2-1
2.1.1 Cable Types .......................................................................2-1
2.1.2 Cable Lengths ...................................................................2-2
2.1.3 Impedance .........................................................................2-4
2.1.4 Attenuation .......................................................................2-4
2.1.5 Maximum Number Of Stations ........................................2-4
2.1.6 Crosstalk............................................................................2-4
2.1.7 Noise ..................................................................................2-5
2.1.8 Temperature......................................................................2-5
2.2 Operating Specifications .............................................................2-5
2.2.1 Ring Speed.........................................................................2-5
2.2.2 Ring Sequence ...................................................................2-5
2.2.3 Connector Types................................................................2-6
2.2.4 LANVIEW LEDs ...............................................................2-8
2.2.5 General Specifications ......................................................2-9
CHAPTER 3 INSTALLING THE TRMIM-20R
3.1 Unpacking The TRMIM-20R ......................................................3-1
3.2 Installing The TRMIM-20R Into The MMAC ............................3-2
3.3 Cabling The TRMIM-20R............................................................3-4
3.3.1 Lobe Cabling......................................................................3-4
3.3.2 Trunk Cabling ...................................................................3-6
3.4 Finishing The Installation ..........................................................3-8

CONTENTS (CONT.)
CHAPTER 4 TESTING AND TROUBLESHOOTING
4.1 Installation Checkout ..................................................................4-1
4.2 Using LANVIEW .........................................................................4-2
APPENDIX A BASIC TOKEN RING NETWORKS
A.1 Basic Token Ring Operation.......................................................A-1
A.2 Design Considerations................................................................A-7
APPENDIX B APPLICATIONS
B.1 Adding To An Existing Token Ring Network............................B-1
B.2 Separate Token Ring Networks In One MMAC........................B-2
B.3 Token Ring Networks Bridged Together ...................................B-3
B.4 MMAC With Ethernet And Token Ring Simultaneously .........B-4
APPENDIX C CALCULATING RING LENGTH
C.1 Rules For Calculating Cable Lengths........................................C-1
C.2 Single Wiring Closet Networks ..................................................C-2
C.3 Multiple Wiring Closet Networks ..............................................C-8
C.4 Calculating Mixed Cable Types ...............................................C-15
iv
CONTENTS

INTRODUCTION
Page 1-1
CHAPTER 1
INTRODUCTION
Welcome to the TRMIM-20R Token Ring Passive Concentrator
Media Interface Module Installation Guide. This guide is
designed to serve as a reference for the installation and
troubleshooting of Cabletron Systems’ TRMIM-20R.
The TRMIM-20R is a token ring network concentrator used in
conjunction with Cabletron System’s Multi Media Access Center
(MMAC). The TRMIM-20R provides ten trunk coupling unit ports
and passive Ring-In and Ring-Out ports. The TRMIM-20R is IEEE
802.5 compliant, and compatible with IBM products. Since the Ring-
In/Ring-Out ports are passive and do not regenerate signal timing,
Adjusted Ring Length (ARL) must be considered when planning cable
lengths.
Prior to installing and operating the TRMIM-20R, read through this
manual to familiarize yourself with its content and to gain an
understanding of the features of TRMIM-20R. A general working
knowledge of Token Ring (IEEE 802.5) networks will be helpful when
installing the TRMIM-20R.
1.1 USING THIS MANUAL
Chapter 1, Introduction, covers using this document, briefly
describes features of the TRMIM-20R and token ring, and lists
related manuals.
Chapter 2, Installation Requirements/Specifications, lists
network requirements that must be met before you install the
TRMIM-20R and specifications for the TRMIM-20R.
Chapter 3, Installing the TRMIM-20R, describes installing the
TRMIM-20R into the MMAC, connecting stations, and inserting the
TRMIM-20R into a token ring network.

INTRODUCTION
Page 1-2
Chapter 4, Testing and Troubleshooting, describes LANVIEW,
Cabletron Systems’ built-in visual diagnostic and status monitoring
system, and gives procedures for verifying the proper installation of
the TRMIM-20R.
Appendix A, Basic Token Ring Networks, covers basic operation
and concepts related to the design of token ring networks.
Appendix B, Applications, presents a variety of network
configurations, showing practical applications for several Cabletron
Systems’ token ring products.
Appendix C, Calculating Ring Length, describes methods for
calculating various ring cable lengths in a passive token ring
network.
1.2 THE TRMIM-20R
The TRMIM-20R, shown in Figure 1-1, is a Media Interface Module
(MIM) that can be installed into a Cabletron Systems’ MMAC-8FNB,
MMAC-8, MMAC-5FNB, MMAC-3FNB or MMAC-3.
The TRMIM-20R functions as a ten port concentrator in a token ring
network providing passive Ring-In and Ring-Out ports and ten trunk
coupling ports.
The TRMIM-20R provides two DB-9 and ten RJ-45 connectors on the
front panel. Two DB-9 connectors permit attachment for shielded
twisted pair (STP) Ring-In and one Ring-Out trunk cabling. Ten
unshielded twisted pair (UTP), RJ-45 connectors support trunk
coupling ports for up to ten token ring stations.
The Ring-In and Ring-Out ports support IBM Type 1, 2, 6 and 9 STP
cable. Each of the TRMIM-20R trunk coupling unit ports supports
station connections via voice grade UTP.
Since the Ring-In and Ring-Out ports are passive trunk connections,
trunk cable length must be calculated giving consideration to
Adjusted Ring Length (ARL). Refer to Appendix C, Calculating
Ring Length, to determine trunk cable length.

INTRODUCTION
Page 1-3
The TRMIM-20R supports voice grade UTP at lobe lengths of up to
100 metersat 4 Mbit/sec and up to 60 meters at 16 Mbit/sec.
Supported cable types and lengths are listed in Chapter 2,
Installation Requirements/Specifications.
Figure 1-1. TRMIM-20R Token Ring Concentrator
TRMIM-20R
RI
RO
UTP
TOKEN RING
1
X
2
X
3
X
4
X
5
X
6
X
7
X
8
X
9
X
10
X

INTRODUCTION
Page 1-4
It is possible to have several network types and media in one MMAC,
such as a shielded twisted pair token ring network and a thin-net
Ethernet network. There are a number of configuration guidelines
concerning multiple networks within an MMAC. These guidelines
are listed in Chapter 3, Installing the TRMIM-20R.
Several MMACs can be connected into the same ring network by
installing token ring concentrators (TRMIM-10R/TRMIM-20R) or
token ring repeaters (TRRMIM-16/TRRMIM-26). The choice between
using concentrators or repeaters depends on specific network
configurations.
The TRMIM-20R incorporates LANVIEW, a useful tool to help you
quickly diagnose physical layer network problems. Several LEDs
(light emitting diodes) are located at the front of the TRMIM-20R.
These LEDs indicate the ring speed, detection of a TRMIM-20R
hardware error, and when a specific port is attached to the ring.
A variety of network management tools can be used to control and
monitor the TRMIM-20R, including Cabletron Systems Local
Management, Cabletron Systems Remote LANVIEW Windows, and
Cabletron Systems SPECTRUM.
1.3 RELATED MANUALS
The manuals listed below should be used to supplement the
procedures and other technical data provided in this manual. The
procedures in them will be referenced, where appropriate, but will not
be repeated in this document.
Cabletron Systems’ Multi-Media Access Center Overview and
Set Up Guide.
Cabletron Systems’ TRMIM-10R Token Ring Concentrator
Media Interface Module Installation Guide.
Cabletron Systems’ TRMIM-12 Token Ring Media Interface
Module Installation Guide.
Cabletron Systems’ TRRMIM-16 Token Ring Repeater Media
Interface Module Installation Guide.

INTRODUCTION
Page 1-5
Cabletron Systems’ TRMIM-22 UTP Passive Token Ring Media
Interface Module Installation Guide.
1.4 RECOMMENDED READING
The following publications are recommended if more information is
required on implementing a token ring network.
Local Area Networks, Token Ring Access Method, IEEE
Standard 802.5
Commercial Building Wiring Standard, EIA Standard
Proposal No. 1907-A(if approved, to be published as EIA/TIA-568)
LAN Troubleshooting Handbook, Mark Miller (1989, M&T
Publishing, Inc.)
1.5 GETTING HELP
If you need additional support related to the Cabletron Systems’
TRMIM-20R, or if you have any questions, comments or suggestions
related to this manual, please contact Cabletron Systems Technical
Support at:
Cabletron Systems
P. O. Box 5005
Rochester, NH 03867-0505
Phone: [phone]

REQUIREMENTS/SPECIFICATIONS
Page 2-1
CHAPTER 2
INSTALLATION REQUIREMENTS/
SPECIFICATIONS
Before you attempt to install your TRMIM-20R, review the
installation requirements and operating specifications outlined in
this chapter. The conditions, guidelines and requirements described
in this chapter must be met to obtain satisfactory performance from
this equipment.
2.1 NETWORK REQUIREMENTS
Take care in planning and preparing the cabling and connections for
your network. The quality of the connections, the length of cables
and other conditions of the installation are critical factors in
determining the reliability of your network.
NOTE: While the TRMIM-20R supports voice grade UTP cabling,
some applications, where existing telephone voice grade UTP is used,
may be subject to crosstalk, electrical noise, signal attenuation or other
environmental factors that exceed acceptable limits. This could reduce
the maximum cable lengths or, in extreme cases, prevent using the
existing cables. In some cases acceptable performance will be obtained
by reducing the lobe length or rerouting the cable. Where more severe
interference is encountered, the installation of new cabling may be
necessary.
The following sections describe the network requirements for
TRMIM-20R operation, however, the same requirements apply
whenever UTP cabling is used within a passive ring segment.
2.1.1 Cable Types
Trunk Cabling - The TRMIM-20R supports IBM Type 1, 2, 6 and 9
shielded twisted pair cable.

REQUIREMENTS/SPECIFICATIONS
Page 2-2
Lobe Cabling - In addition to IBM Type 3 unshielded twisted pair
(UTP), the TRMIM-20R supports voice grade UTP cable as described
in EIA Standard Proposal No. 1907-A. Table 2-1 lists IBM cable
types.
2.1.2 Cable Lengths
The TRMIM-20R is a passive concentrator. It neither regenerates
nor retimes ring signals and the cable lengths used with the
concentrator must consider the Adjusted Ring Length (ARL). ARL
results from recovery processes that attempt to restore continuity to a
broken ring. The ARL is the longest potential ring length, the ring
that would exist following recovery from a failure of the shortest ring
segment trunk cable. Refer to the discussion of token ring concepts
related to ARL in Appendix A. Appendix C describes how to calculate
cable lengths in your network, giving consideration to ARL.
Considering ARL, two cable lengths must be defined: Lobe Length
and Trunk Length. Their combined length defines the path
between two token ring stations and cannot exceed the maximum
drive distance.
Lobe Length - This is the physical length of UTP cable connecting a
station to the trunk coupling unit (TCU) port on the TRMIM-20R.
The recommended maximum length for the longest UTP lobe cable is
shown in Table 2-2. This is a recommended maximum because
cable length calculations for passive ring connections described in
Appendix C could produce a maximum lobe length for your network
that exceeds this limit. However, installing a lobe that exceeds the
recommended maximum should be avoided since it could restrict
future expansion of the network.
Trunk Length - This is the physical length of the STP cabling in the
main ring path, from Ring-Out to Ring-In on each of the attached
token ring devices. The cable budget for the trunk cabling must be
determined by performing the calculations described in Appendix C.
In a totally passive ring (no repeaters or active concentrators, etc. on
the ring), the entire trunk length must be included in calculation of
cable lengths. When only a portion of the ring is passive, the
combined length of the trunk cabling between the passive components
must be considered in the cable length calculations.

REQUIREMENTS/SPECIFICATIONS
Page 2-3
Drive Distance - Drive distance is the limit of reliable signal
propagation without the installation of repeaters in the ring. The
maximum drive distance using Type 1 STP cabling is 770 meters
(2525 feet) at 4 Mbit/sec and 346 meters (1138 feet) at 16 Mbit/sec.
These limits include the combined length of all trunk cables plus
twice the length of the longest lobe cable. (When UTP lobe cables are
used, as with the TRMIM-20R, determining the overall drive distance
requires converting the UTP cable lengths to their Type 1 equivalent
length and then using the Type 1 equivalent to calculate cable
lengths.)
Table 2-1. IBM Cable Types
Type 1 Two shielded twisted pairs (STP) of 22 AWG solid wire
for data. Used for the longest cable runs within the
walls of buildings.
Type 2 Similar to Type 1 data cable, but having four additional
unshielded twisted pairs of 22 AWG solid wire carried
outside of the shield casing. Typically used for voice
communication.
Type 3 Four unshielded twisted pairs (UTP) of 24 AWG solid
wire for data or voice communication. Used for cable
runs in walls of buildings.
Type 5 Two 100/140 µm optical fibers in a single sheath.
Type 6 Two STP of 26 AWG stranded wire for data. This type
is used in patch panels or to connect devices to/from
wall jacks.
Type 8 One flat STP of 26 AWG stranded wire for under carpet
installation.
Type 9 Similar to Type 1, but uses 26 AWG solid wire.
NOTES:
1. Refer to Appendix C for cable conversion factors.
2. Table 2-1 lists all cable types for reference. The TRMIM-20R
supports Type 3 for TCU port cabling and Types 1, 2, 6, and 9 as
trunk cabling.

REQUIREMENTS/SPECIFICATIONS
Page 2-4
Table 2-2. Recommended Maximum Lobe Length
Maximum Lobe Length
4 Mbit/sec 16 Mbit/sec
Voice Grade UTP
(or IBM Type 3) 100 meters 60 meters
2.1.3 Impedance
The characteristic impedance for UTP cable is 100 ohms ±15% and
150 ohms (@ 1 MHz to 20 MHz) ±10% for STP cable.
2.1.4 Attenuation
Attenuation values include the attenuation of the cables, connectors,
and patch panels. Maximum attenuation for UTP cable segments
used with the TRMIM-20R is:
4.0 MHz 16.0 MHz
UTP (Voice Grade) 56 dB/km 131 dB/km
STP (IBM Types 1 & 2) 22 dB/km 45 dB/km
STP (IBM Types 6 & 9) 33 dB/km 66 dB/km
2.1.5 Maximum Number of Stations
The maximum number of stations in a single ring, using UTP cabling,
is 72 stations, regardless of the ring speed.
2.1.6 Crosstalk
Crosstalk is caused by signal coupling between the different cable
pairs contained within a multi-pair cable bundle.

REQUIREMENTS/SPECIFICATIONS
Page 2-5
2.1.7 Noise
Noise can be caused by either crosstalk or externally induced
impulses. If noise induced errors are suspected, it may be necessary
to re-route cabling away from potential noise sources (motors,
switching equipment, high amperage equipment), or to ensure that
the electrical wiring in the area is properly wired and grounded.
2.1.8 Temperature
The attenuation of PVC insulated cable varies significantly with
temperature. At temperatures greater than 40°C (104°F), it is
strongly recommended that you use plenum-rated cables to ensure
that cable attenuation remains within specification. Check the cable
manufacturer’s specifications.
2.2 OPERATING SPECIFICATIONS
This section describes the operating specifications for the
TRMIM-20R. Cabletron Systems, Inc. reserves the right to change
these specifications at any time without notice.
2.2.1 Ring Speed
The TRMIM-20R can be operated at a ring speed of either 4 Mbit/s or
16 Mbit/s. Selection of the ring speed is accomplished either by a
hardware jumper on the TRMIM-20R or by software selection. The
software selection overrides the jumper selection.
2.2.2 Ring Sequence
When multiple token ring boards (set to the same ring speed) are
installed in adjacent slots within an MMAC, they can be attached via
the FNB to create a larger ring network. The default configuration
for the TRMIM-20R attaches boards in adjacent slots automatically
at power on, but the configuration can be modified via network
management software, so that adjacent boards are attached or
detached, resulting in changes in the ring sequence.

REQUIREMENTS/SPECIFICATIONS
Page 2-6
When a TRMIM-20R is installed, the ring sequence starts at the
externally accessible Ring-In port. If the concentrator is detached (by
software, incompatible ring speed or empty adjacent slots) from other
token ring boards, the ring sequence is restricted to the TRMIM-20R
and goes from the Ring-In port to each of the TCU ports, in ascending
port number order, and then out the Ring-Out port.
When multiple token ring boards are installed in consecutive slots
and attached via the FNB, the sequence is in ascending slot number
order. When a concentrator, such as the TRMIM-20R is attached via
the FNB to other token ring boards, the ring sequence begins at the
Ring-In port of the concentrator and is first routed out, via the FNB,
to the next (higher slot number) token ring board on the bus. An
empty slot or non-token ring board causes the FNB trunk connection
to loop back to the first token ring board in the sequence and
continues to thread through the TCU ports and token ring boards
until it returns to the concentrator. There, it threads through the
TCU ports and finally to the Ring-Out port.
Example: TRMIM-22 in slot 1 with ports 2, 5, 8, & 12 in use.
TRMIM-20R in slot 2 with ports 1, 2, 3, 5, and 6 in use.
TRMIM-12 in slot 3 with ports 1, 5, 7, 11, & 12 in use.
An FNB is installed in the MMAC.
All three boards are attached via the FNB.
The ring sequence for this example is from Slot 2, Ring-In port to the
FNB and Slot 3, ports 1, 5, 7, 11, 12, via the FNB to Slot 1 ports 2, 5,
8, 12; then, returning to Slot 2 ports 1, 2, 3, 5, and 6, then out the
Ring-Out port of the TRMIM-20R.
2.2.3 Connector Types
Trunk Coupling Unit Ports - Ten Female RJ-45 connectors are
located on the front panel of the TRMIM-20R. They are labeled 1
through 10. Figure 2-1 shows the pin layout and signal connections
for these connectors.

REQUIREMENTS/SPECIFICATIONS
Page 2-7
Rx +
Tx-
Tx+
Rx-
1
2
3
4
5
6
7
8
FEMALE RJ
-45
TCU Ports: Pin Pin
1 No Connection 5 RX–
2 No Connection 6 TX+
3 TX– 7 No Connection
4 RX+ 8 No Connection
Figure 2-1. Trunk Coupling Unit RJ-45 Pinout
STP Trunk Connections - Two Female DB-9 connectors for
attaching STP trunk cables are located on the lower left side of the
TRMIM-20R front panel. Figure 2-2 shows the signal and pin
assignments for the STP ring interface.
Trunk Port: Pin Pin
Ring-In 1 RX– (Main Ring) 5 TX– (Backup Ring)
2 Ground 6 RX+ (Main Ring)
3 Ground 7 Ground
4 Ground 8 Ground
9 TX+ (Backup Ring)
Ring-Out 1 TX– (Main Ring) 5 RX– (Backup Ring)
2 Ground 6 TX+ (Main Ring)
3 Ground 7 Ground
4 Ground 8 Ground
9 RX+ (Backup Ring)
Figure 2-2. Trunk Cable Connections
FEMALE DB-9 RECEPTACLE
TX+ (Backup Ring)
6
7
8
9
1
2
3
4
5
(Main Ring) RX-
Common
Ground Common
Ground
(Backup Ring) TX-
FEMALE DB-9 RECEPTACLE
RX+ (Backup Rin
g)
6
7
8
9
1
2
3
4
5
(Main Ring) TX-
Common
Ground Common Ground
(Backup Ring) RX-
RX+ (Main Ring) TX+ (Main Ring)
RING- IN RING-OUT

REQUIREMENTS/SPECIFICATIONS
Page 2-8
6
7
8
9
1
2
3
4
5
PRIMARY RING
BACKUP RIN
G
Trunk Wrap Connector - Two male wrap plugs are provided with
each TRMIM-20R. The TRMIM-20R does not automatically wrap.
When no external trunk cable is attached at either ring port (Ring-In/
Ring Out), or if a ring port must be wrapped without using
management software, a wrap plug must be attached to the
appropriate ring port. The wrap plug connects the primary and
backup rings. Figure 2-3 shows the wiring for the wrap plug.
Figure 2-3. Trunk Wrap Plug
2.2.4 LANVIEW LEDs
There are a number LANVIEW LEDs on the front panel of the
TRMIM-20R. The exact locations and functions for these LEDs are
illustrated in Figure 2-4.
Figure 2-4. TRMIM-20R LANVIEW LEDs
ATTACHED (GREEN - 10)
ERR (Red)
RING-IN/RING-OUT (GREEN - 2)
16 Mb (Yellow)
TRMIM-20R
1
X
7
X
SN
7
8
9
10
1
2
3
4
5
6
ERR
16Mb
A
T
C
H
E
D
A
T
A
T
C
H
E
D
A
T
R I
RO

REQUIREMENTS/SPECIFICATIONS
Page 2-9
Table 2-3. LANVIEW LEDs
Label Color Description
16 Mb Yellow Ring Speed Indicator
ON TRMIM-20R is set for 16 Mbit/sec
OFF TRMIM-20R is set for 4 Mbit/sec
RI/RO Green Ring-In/Ring-Out Status (2)
ON Respective ring port is in a non-wrap state
OFF Respective ring port is in a wrap state
ERR Red ON TRMIM-10R hardware error detected
OFF Normal operation
Attached Green Link Attached (10 - One for each TCU port)
ON The respective port is inserted into the
ring.
OFF The respective port is removed (bypassed)
from the ring.
2.2.5 General Specifications
SAFETY
WARNING: It is the responsibility of the person who sells the
system to which the TRMIM-20R will be a part to ensure that the
total system meets allowed limits of conducted and radiated
emissions.
This equipment is designed in accordance with UL478, UL910,
NEC 725-2(b), CSA, IEC, TUV, VDE Class A, and meets FCC
part 15, Class A limits.
SERVICE
MTBF (MHBK-217E)> 109,471 hrs.
MTTR < 0.5 hr.

REQUIREMENTS/SPECIFICATIONS
Page 2-10
PHYSICAL
Dimensions 13.4D x 11.5H x 2.0W inches
(34.0D x 29.2H x 5.1W centimeters)
(includes front panel)
Weight 2 lbs. 2 oz.
(963.9 grams)