Black Box MX864A User manual

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CUSTOMER
SUPPORT
INFORMATION
MARCH 2004
MX864A
MX866A
MX868A
Stat-4, Stat-8, and Stat-24

FCC AND IC RFI STATEMENTS
1
FEDERAL COMMUNICATIONS COMMISSION
AND
INDUSTRY CANADA
RADIO FREQUENCY INTERFERENCE STATEMENTS
This equipment generates, uses, and can radiate radio-frequency energy, and if not installed and used
properly, that is, in strict accordance with the manufacturer’s instructions, may cause interference to radio
communication. It has been tested and found to comply with the limits for a Class A computing device in
accordance with the specifications in Subpart B of Part 15 of FCC rules, which are designed to provide
reasonable protection against such interference when the equipment is 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 digital apparatus does not exceed the Class A limits for radio noise emission from digital apparatus set out in the Radio
Interference Regulation of Industry Canada.
Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les limites applicables aux appareils numériques
de la classe A prescrites dans le Règlement sur le brouillage radioélectrique publié par Industrie Canada.

STAT-4, STAT-8, AND STAT-24
2
INSTRUCCIONES DE SEGURIDAD (Normas Oficiales Mexicanas Electrical Safety Statement)
1. Todas las instrucciones de seguridad y operación deberán ser leídas antes de que el aparato eléctrico sea operado.
2. Las instrucciones de seguridad y operación deberán ser guardadas para referencia futura.
3. Todas las advertencias en el aparato eléctrico y en sus instrucciones de operación deben ser respetadas.
4. Todas las instrucciones de operación y uso deben ser seguidas.
5. El aparato eléctrico no deberá ser usado cerca del agua—por ejemplo, cerca de la tina de baño, lavabo, sótano
mojado o cerca de una alberca, etc..
6. El aparato eléctrico debe ser usado únicamente 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 eléctrico debe ser situado de tal manera que su posición no interfiera su uso. La colocación del aparato
eléctrico sobre una cama, sofá, alfombra o superficie similar puede bloquea la ventilación, no se debe colocar en
libreros o gabinetes que impidan el flujo de aire por los orificios de ventilación.
10. El equipo eléctrico deber ser situado fuera del alcance de fuentes de calor como radiadores, registros de calor, estufas
u otros aparatos (incluyendo amplificadores) que producen calor.
11. El aparato eléctrico deberá ser connectado a una fuente de poder sólo del tipo descrito en el instructivo de
operación, o como se indique en el aparato.
12. Precaución debe ser tomada de tal manera que la tierra fisica y la polarización del equipo no sea eliminada.
13. Los cables de la fuente de poder deben ser guiados de tal manera que no sean pisados ni pellizcados por objetos
colocados sobre o contra ellos, poniendo particular atención a los contactos y receptáculos donde salen del aparato.
14. El equipo eléctrico debe ser limpiado 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. Servicio por personal calificado deberá ser provisto cuando:
A: El cable de poder o el contacto ha sido dañado; u
B: Objectos han caído o líquido ha sido derramado dentro del aparato; o
C: El aparato ha sido expuesto a la lluvia; o
D: El aparato parece no operar normalmente o muestra un cambio en su desempeño; o
E: El aparato ha sido tirado o su cubierta ha sido dañada.

TRADEMARKS USED IN THIS MANUAL
3
TRADEMARKS USED IN THIS MANUAL
Any trademarks mentioned in this manual are acknowledged to be the property of the trademark owners.

STAT-4, STAT-8, AND STAT-24
4
Contents
Chapter Page
1. Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 Available Models. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.3 Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3. Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2 Site and Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.3 Description of Internal Jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.4 How to Set the Jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.5 Installing the Mux in 19" Racks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.5.1 Installing a Single Stat-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.5.2 Installing Two Stat-8 Muxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.5.3 Installing the Stat-24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.6 Cable Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.6.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.6.2 Sub-Channel Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.6.3 Main (Composite) Channel Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.6.4 Power Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.7 Powering On the Mux . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.8 Stat Mux Configuration Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.8.2 Configuration Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.8.3 Outline of Configuration Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.9 Starting the Configuration Session . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.9.1 Using the Stat Mux Configuration Program. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.9.2 Preparing for Configuration Session. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.9.3 Starting the Configuration Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.10 Configuration Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.1 Controls, Indicators, and Connectors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.1.1 Stat-4 and Stat-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.1.2 Stat-24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
4.2 Operating Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
4.2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
4.2.2 Powering on the Stat Mux . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
4.2.3 Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
4.2.4 Powering Off the Stat Mux. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
4.3 What to Do in Case of Malfunction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
4.3.1 Preliminary Checks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
4.3.2 Check Stat Mux Indications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

CONTENTS
5
Chapter Page
5. Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
5.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
5.2 Description of Test Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
5.2.1 Local Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
5.2.2 Remote Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
5.2.3 Modem Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Appendix A: Interface Pinouts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
A.1 Main (Composite) Channel Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
A.2 Sub-Channel Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Appendix B: Stat Mux Configuration Record. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Appendix C: Quick Start Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
C.1 How to Use This Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
C.2 What You Need. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
C.3 Configuration Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
C.3.1 Local Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
C.3.2 Transfer Configuration to the Remote Stat Mux . . . . . . . . . . . . . . . . . . . . . . . . . 56
C.3.3 Ending the Configuration Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Appendix D: Stat Mux Configuration Transfer Facilities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
D.1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
D.2 Configuration Storage and Transfer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
D.2.1 Description of Configuration Storages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
D.2.2 Managing the Configuration Storages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

STAT-4, STAT-8, AND STAT-24
6
1. Specifications
Multiplexor Type: Statistical TDM
User Channels: MX864A: 4; MX866A: 8; MX868A: 24
Speed: Channel: MX864A, MX866A: 300 bps to 19.2 kbps; MX868A: 75 bps to 38.4 kbps;
Composite: All models: Up to 19.2 kbps
Flow Control: Hardware: DTR/CTS for end-to-end, RTS/CTS for sub-channel to device;
Software: X-ON/X-OFF
Diagnostics: Local and remote loopback on channels and composite
User Controls: (3) internal jumpers: INIT/NOR, PIN 21 ON-OFF, and GND
Interface: Channel: RS-232, async; Composite: RS-232, sync
Connectors: MX864A: Channel: (4) RJ-45, Composite: (1) DB25 male (DTE);
MX866A: Channel: (8)RJ-45, Composite: (1) DB25 male (DTE);
MX868A: Channel: (24) RJ-45, (1) DB25 male (DTE)
Indicators: MX864A: (9) LEDs: (1) Power, (4) Port numbered 1 through 4, (1) Sync, (1) Err, (1) OVF, (1) Test;
MX866A: (13) LEDs: (1) Power, (8) Port numbered 1 through 8, (1) Sync, (1) Err, (1) OVF, (1) Test;
MX868A: (29) LEDs: (1) Power, (24) Port numbered 1 through 24, (1) Sync, (1) Err, (1) OVF, (1) Test
Temperature Tolerance: 32 to 122°F (0 to 50°C)
Relative Humidity: Up to 95%, noncondensing
Power: 115 VAC, 47 to 63 Hz
Size: MX864A, MX866A: 1.7"H x 8.5"W x 9.5"D (4.3 x 21.6 x 24.1 cm);
MX868A: 1.7"H x 17.2"W x 9.6"D (4.3 x 43.7 x 24.4 cm)
Weight: MX864A: 3.1 lb. (1.4 kg);
MX866A: 3.5 lb. (1.6 kg);
MX868A: 5.7 lb. (2.6 kg)

7
2. Introduction
2.1 Functional Description
The Stat-4, Stat-8, and Stat-24 are advanced, full-function compact statistical multiplexors. They’re capable of
multiplexing asynchronous data sub-channels at data rates of 75 to 38,400 bps onto a single composite
synchronous channel operating at up to 19,200 bps. The Stat-4 has four sub-channels, the Stat-8 has eight
sub-channels, and the Stat-24 has 24 sub-channels. An external clock signal automatically determines the
composite channel rate, and you select sub-channel characteristics and other system features via configuration
menus. All units are available in desktop versions, which also install in 19" racks with rack adapter kits.
The Stat-4, Stat-8, and Stat-24 use a dynamic data buffer management technique to allocate available buffer
capacity according to sub-channel activity. Error-free end-to-end data transmission is ensured by powerful and
efficient error detection and automatic retransmission, completely transparent to the user.
The muxes provide independent hardware and software flow control for each sub-channel, both end-to-end
flow control (DTE to DTE) and terminal flow control (DCE to DTE). For compatibility with most applications,
choose from among several software flow-control characters.
The Stat-4, Stat-8, and Stat-24 permit full system configuration (including configuration downloading from the
local stat mux to the remote stat mux, and vice-versa) from any sub-channel port. The stat mux uses a password
to prevent unauthorized configuration changes.
You can configure the mux with any standard cathode-ray terminal (CRT), using a simple, menu-driven facility.
Configuration parameters are stored in non-volatile memory and are immediately available upon power-up.
To facilitate initial system configuration, the multiplexors store—in addition to the user-selected
configuration—a set of default configuration parameters (factory setting), that you can select via a jumper, to
provide a common starting point for any stat mux.
The Stat-4, Stat-8, and Stat-24 have comprehensive diagnostics functions, including automatic self-test upon
power-on, local and remote sub-channel loopback, and local and remote composite channel loopback. Front-
panel indicators show the condition of each sub-channel and composite link synchronization status. In
addition, the muxes control the V.54 pins (pins 18 and 21) of the RS-232 interface serving the composite link,
thereby allowing control of analog and remote digital loopback functions of the modem connected to the stat
mux.
2.2 Available Models
The following models are available:
Model Number Name Ports
MX864A Stat-4 (4) RJ-45, (1) DB25
MX866A Stat-8 (8) RJ-45, (1) DB25
MX868A Stat-24 (24) RJ-45, (1) DB25
CHAPTER 2: Introduction

STAT-4, STAT-8, AND STAT-24
8
2.3 Typical Applications
Figure 2-1 shows a typical application that uses a Stat-24 to multiplex the data lines used to connect a large
number of asynchronous terminals (up to 24) to the host computer. The data lines use various data rates. The
Stat-24 statistically multiplexes sub-channel data to form a composite data stream having a rate much smaller
than the arithmetical sum of the individual sub-channel rates. The required composite link rate depends on the
Stat-24’s buffer capacity versus sub-channel traffic statistics and allowable delay.
The composite data is sent via modems to the remote Stat-24, where it is demultiplexed and distributed to the
local users at their nominal rate (that may differ from the nominal host transmission rate).
Reliable operation of any statistical multiplexor requires the equipment connected to its sub-channels to use
some form of flow control. One of the main advantages of the Stat-4, Stat-8, and Stat-24 is that the flow-control
method used at each of the two sub-channel ends can differ (for example, hardware control at one end,
software control at the other end), and the conversion is transparently performed by the stat muxes.
Figure 2-1. Typical stat mux application.

9
CHAPTER 3: Installation
3. Installation
3.1 General
The Stat-4, Stat-8, and Stat-24 are delivered completely assembled. Install each mux on top of a bench or shelf,
or optionally mount it in a 19" rack (via rack adapter kits). Mechanical and electrical installation procedures
appear in the following paragraphs.
After installing the mux, refer to Section 3.8 for system configuration information and procedures (including
sub-channel bit rate, data format, and flow-control mode selection).
If you encounter a problem, refer to Chapter 5 for test and diagnostic instructions.
3.2 Site and Power Requirements
Power. Install within 5 feet (1.5 m) of a grounded AC outlet capable of furnishing 115 VAC or 230 VAC,
according to the nominal supply voltage of the unit.
Ambient Requirements. The stat mux will operate properly in any ambient conditions suitable for operation of
electronic computer equipment and peripherals. The stat mux, however, can operate without performance
degradation over a wide range of temperatures 32 to 122°F (0 to 50°C) at relative humidities up to 95%,
non-condensing.
Grounding. The stat muxes have a rear ground screw, which is used for grounding all the metal parts of the
chassis.
3.3 Description of Internal Jumpers
WARNING
Avoid electrical shock! Always turn the power switch off and disconnect the power
cable from mains before opening the stat mux.
General. The Stat-4, Stat-8, and Stat-24 have three internal jumpers. Refer to Figure 3-1 for Stat-4 and Stat-8 and
to Figure 3-2 for Stat-24, and use the following description.
1. INIT/NOR jumper. Use this jumper to select the default set of configuration parameters stored in the
stat mux. The jumper has two positions:
• NOR: Normal operation. The stat mux uses parameters selected by the user during the last
configuration session.
• INIT: Initialization. The stat mux uses the default configuration (determined by factory and common
to all stat mux units). To select the default configuration, set the jumper to INIT, then apply power to
the stat mux, or press the RESET button while the stat mux is powered. The default configuration is
loaded during power-up.
Factory setting is NOR.

STAT-4, STAT-8, AND STAT-24
10
When delivered, the non-volatile memory of the stat mux is already loaded with the default configuration, so
the stat mux is configured in accordance with the factory settings. You may have to select again the default
configuration (INIT) again in the following cases:
• After an error during the configuration session, which either prevents communication between the control
terminal and the stat mux, or is difficult to trace and correct.
• The description of the configuration loaded into the stat mux has been lost, so it’s not possible to enter the
configuration mode in the NOR mode. To avoid this inconvenience, always keep a record of the last
configuration parameters (a typical record form is shown in Appendix B).
After you load the default configuration by setting the jumper to INIT and powering up or resetting the stat
mux, the default configuration becomes the current stat mux configuration. Return the jumper to the NOR
position to allow configuration.
2. PIN 21 ON-OFF jumper. Pin 21 of the standard RS-232 interface can serve either as a signal quality
indication (SQ) line, or as a remote loopback command line. The actual function depends on the specific
model of modem you’re using, and a jumper allows adapting the stat mux to the modem connected to the
composite (main) link connector.
The jumper has two positions:
• PIN 21 ON: Set the jumper to this position when the modem uses pin 21 as a remote loopback
command line. This connects the internal stat mux pin 21 driver to this pin, and allows you to control
this modem function using the diagnostics screen.
• PIN 21 OFF: Set the jumper to this position when the modem uses pin 21 as a signal quality indication
output. Use this position whenever in doubt about the actual function of the pin in the specific modem
model you use. When the jumper is in this position, you no longer have control of the modem’s remote
loopback function from the diagnostics screen. The factory setting is OFF.
3. GND jumper. This jumper controls the connection between the signal ground lines to the chassis ground
lines. The installation manager determines the appropriate position.
The jumper has two positions:
• C (connect)—signal ground connected to chassis ground.
• D (disconnect)—signal ground disconnected from chassis ground.
Factory setting is D (Disconnect).
3.4 How to Set the Jumpers
WARNING
Avoid electric shock! Always turn the power switch off and disconnect the power cable
from mains before opening the stat mux.
Follow these steps to set the jumpers:
1. Access the printed circuit board of the stat mux by opening the screw (or screws) fastening the top cover
to the case, and remove the top cover.

11
CHAPTER 3: Installation
2. Refer to Figure 3-1 or 3-2 and identify jumper locations and settings. Change the settings as required.
3. Reinstall the stat mux cover, and install and tighten the screws.
Figure 3-1. Stat-4 and Stat-8 internal jumpers.
Figure 3-2. Stat-24 internal jumpers.

STAT-4, STAT-8, AND STAT-24
12
3.5 Installing the Mux in 19" Racks
Install the stat muxes in 19" racks. Rack height is 1U (1.75"). The width of the Stat-8 is slightly less than half of
the available mounting width, and Stat-24 width is equal to the available width. Two rack adapter kits are
available for the Stat-8; one kit provides the hardware you need to install a single mux, and the other provides
the hardware you need to install two muxes, side-by-side. Another rack adapter kit is available for the Stat-24.
Call Technical Support for details.
WARNING
Disconnect the units from AC power while performing the following procedures.
3.5.1 INSTALLING A SINGLE STAT-8
The rack adapter kit for single-mux installation includes one short bracket and one long bracket. Fasten the
brackets via screws to the two side walls of the case, as shown in Figure 3-3.
To prepare the mux for rack installation, attach the two brackets to the side walls of the mux. Each bracket
fastens via two screws (with flatwashers), which you insert into the two front holes on the side wall (nuts are
already in place, on the inner side of the wall). After attaching the brackets, the mux is ready to install in the
19" rack. Fasten the brackets to the side rails of the 19" rack via four screws (not included in the kit), two on
each side.
Figure 3-3. Installing a single Stat-8 in a 19" rack.

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CHAPTER 3: Installation
3.5.2 INSTALLING TWO STAT-8 MUXES
The adapter kit includes two adapter brackets (and various hardware) for attaching the two muxes side by side.
Refer to Figure 3-4 and follow these steps:
1. Remove the cover from the mux that will be on the right-hand side of the rack.
2. Position one of the two U brackets supplied in the kit on the slots inside of the inner left-hand wall, and
align its holes with the holes on the wall.
3. Insert the flat washers over one pair of long screws and screw them through the U bracket into the holes
on the wall.
4. Repeat steps 2 and 3 above for the other U bracket.
5. Hold the second mux close to the left wall of the opened rack, and using a screwdriver, drive the four
screws until their ends emerge from the left wall and engage the holes on the right side of the second
mux. Tighten each screw one turn at a time—do not tighten one screw completely before moving on to
the next. Continue to tighten the screws until their heads rest against the U bracket and the two muxes are
in contact.
6. Reinstall the cover over the right-side mux.
7. Fasten one adapter bracket (7A) to the side wall of each mux. Use the four short screws (7B) and flat
washers (7C) supplied in the kit.
8. You can now fasten the assembled units to the side rails of the 19" rack with four screws (not included
in the kit), two on each side.

STAT-4, STAT-8, AND STAT-24
14
Figure 3-4. Installing two Stat-8 muxes side by side.

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CHAPTER 3: Installation
3.5.3 INSTALLING THE STAT-24
The rack adapter kit for Stat-24 rack installation includes two short brackets. The brackets are fastened via
screws to the two side walls of the case, as shown in Figure 3-5. To prepare the mux for rack installation, attach
the two brackets to the side walls of the mux. Each bracket is fastened with two screws (with flatwashers), which
are inserted into the two front holes on the side wall (nuts are already in place, on the inner side of the wall).
After attaching the brackets, the mux is ready to install in the 19" rack. Fasten the brackets to the side rails of
the 19" rack with four screws (not included in the kit), two on each side.
Figure 3-5. Installing the Stat-24 in a 19" rack.
3.6 Cable Connections
3.6.1 GENERAL
The Stat-4, Stat-8, and Stat-24 have one standard DB25 connector, serving the main channel, located on the
rear panel, and RJ-45 connectors, located on the front panel, for the sub-channels.
3.6.2 SUB-CHANNEL CONNECTIONS
Stat mux sub-channel interfaces are configured as data communication equipment (DCE) interfaces, allowing
you to connect the mux, via RS-232 port cables, directly to data terminal equipment (DTE). When you use
modems to extend range (tail-end circuits), you need crossover cables. Sub-channel interfaces are
asynchronous, so clock signals are not supported, or required. Appendix A lists pin allocation in stat mux
sub-channel connectors and provides typical wiring diagrams for straight-through and crossover cables.
3.6.3 MAIN (COMPOSITE) CHANNEL CONNECTION
The stat mux’s composite channel interface is configured as a DTE interface. It connects to a synchronous
modem providing the clock signal that determines the stat mux’s composite channel data rate. Appendix A also
lists the pin allocation for the stat mux’s composite channel connector.

STAT-4, STAT-8, AND STAT-24
16
3.6.4 POWER CONNECTION
The Stat-4, Stat-8, and Stat-24 have standard IEC three-prong connectors with an integral fuse.
3.7 Powering On the Mux
Connect the power cable between the AC mains connector on the rear panel and a standard grounded AC
outlet, then set the rear-panel POWER switch to On. The front-panel PWR indicator should light.
After you turn on the mux, the SYNC indicator should light. If the link to the far stat mux is still not
operational, the SYNC indicator will flash. Check that after a few seconds (during which the stat mux performs
a self-test), the ERR indicator goes out. For additional information on stat mux indicators, refer to Chapter 4.
3.8 Stat Mux Configuration Information
3.8.1 INTRODUCTION
The stat mux can operate in three modes:
1. Normal operation mode, described in detail in Chapter 4.
2. Parameter configuration mode. Allows user to set up parameters of local and remote stat mux units.
This mode provides two types of functions:
• Parameter-selection functions.
• System-management functions, used to save (store) selected parameters, transfer configurations
between the local and remote units, activate new configurations, and select passwords.
3. Diagnostics mode. Stat mux diagnostic functions include local and remote loops on each sub-channel and
on the composite channel, and modem loops (analog and optionally remote digital loopback). Refer to
Chapter 5 for additional details.
Activate the parameter configuration mode and the diagnostics mode from the command terminal, using the
stat mux configuration program. This paragraph outlines the configuration parameters available to you.
Section 3.9 provides step-by-step instructions on starting configuration and diagnostics sessions. Section 3.10
provides in-depth information on each menu and the purpose of each parameter or diagnostics screen.
3.8.2 CONFIGURATION INFORMATION
The stat mux has two types of configuration parameters:
1. System parameters, which affect both stat mux units connected in a link and also affect all their
sub-channels. Table 3-1 lists system parameters.
2. Sub-channel parameters, which affect only the operation of a single sub-channel. Table 3-2 lists
sub-channel parameters.

17
Table 3-1. STM system parameters and factory settings.
No. Parameter Function Available Factory
Selections Setting
1 PASSWORD Controls access Any two characters RD
to configuration except those used (capital
as X-ON and X-OFF letters)
control characters
2 X-ON CONTROL When using 11H (DC1) 11H
CHARACTER software flow 12H (DC2)
control, causes 13H (DC3)
the receiving 14H (DC4)
terminal to start 91H
data transfer 92H
93H
94H
3 X-OFF CONTROL When using Same range as for 13H
CHARACTER software flow X-ON, but the
control, causes selected character
the receiving must be different
terminal to stop from the X-ON
transfer of data character
CHAPTER 3: Installation

STAT-4, STAT-8, AND STAT-24
18
Table 3-2. Sub-channel parameters and factory settings.
No. Parameter Function Available Factory
Selections Setting
1 BAUD RATE Sub-channel 75, 110, 150, 300, 9600
data rate 600, 1200, 2400,
4800, 9600, 19200,
38400 bps
2 DATA BITS Number of data 5, 6, 7, 8 8
bits in sub-channel
data frame
3 PARITY Type of parity Odd, Even None
used in sub-channel Space, Mark,
data frame None
4 STOP BITS Number of stop 1, 1.5, 2 1
bits in sub-channel
data frame
5 STAT-MUX-TO- Controls software On On
DTE SOFTWARE flow-control function Off
FLOW CONTROL at the local end of
the sub-channel.
When on, see
also Table 3-1,
No. 2, 3.
6 END-TO-END Activates end-to-end On On
SOFTWARE FLOW software flow control. Off
CONTROL When on, see also
Table 3-1, No. 2, 3.
7 END-TO-END DTR Activates end-to-end On On
FLOW CONTROL hardware flow control Off
(via DTR line)
8 RTS CONTROL Enables the transfer On Off
PASS of the RTS state to Off
the remote DCD line

CHAPTER 3: Installation
19
3.8.3 O UTLINE OF C ONFIGURATION P ROGRAM
The organization tree of the configuration program is shown in Figure 3-6.