INSTALLATION
and
OPERATION MANUAL
Table of Contents
i
Chapter 1: Introduction
1.1 General …………………………………………………. 1
1.2 Data Port Interfaces ……………………………………. 2
1.3 G.703/64K Interface …………………………………… 3
1.4 Features ………………………………………………… 6
1.5 Specifications ………………………………………...… 6
1.6 Loop Back Diagnostics ………………………………… 7
1.7 Timing Considerations …………………………………. 7
Chapter 2: Installation and Operation
2.1 General …………………………………………………. 9
2.2 Site Preparation ………………………………………… 9
2.3 Mechanical Assembly ………………………………….. 9
2.4 Electrical Installation …………………………………... 9
2.5 Dip Switch and Jumper Settings ………………….……. 11
2.6 Front Panel ……………………………………………... 13
2.7 Loop Back Operation …………………………………... 13
2.8 Auto Delay Feature …………………………………….. 16
Chapter 3: Optional Rack Mounting ………………... 17
Appendix A: DIP Switch Setting Tables …………..... 19
A.1 DSW1 Setting (Clock Source Setup) ……………….…. 19
A.2 DSW2 Setting (Data Port Setup) ……………………… 20
A.3 DSW3 Setting (Delay Setup) ………………………….. 21
Table of Contents
ii
Appendix B: Cable Pin Out Definition Tables ……. 23
B.1 DB9 Connectors ……………………………………….. 23
B.2 User Data Port Connector for RS-232 ……………….… 24
B.3 User Data Port Connector for RS-530 …………………. 25
B.4 User Data Port Connector for V.35 ………………….… 26
B.5 User Data Port Connector for X.21 ………………….… 27
B.6 User Data Port Connector for RS-449 ……………….… 28
B.7 User Data Port Connector for V.36 ……………………. 29
Chapter 1: Introduction
1
1.1 General
The MUX128/2*64 Access Unit is used to multiplex two
G.703/64Kbps bit flows to one 128K Synchronous Data Port
or vice versa.
Referring to the Point-to-Point example below, no
additional bandwidth is available for synchronization.
Therefore, it is important that the transmission delay between
the two units be less than half of a 64Kbps cycle.
Figure 1-1: Point to point connection diagram
The delay between A CH 64K and B CH 64K should be
the same. Any delay may be manually nulled via DIP switch
settings. The delay may also be automatically detected while
in “Auto Delay” mode for automatic nulling. In either case,
for normal operation, the delay between channels must remain
fixed after setting.
Figure 1-2: Multiplex/De-multiplex Timing Diagram
1 2 3 4 5 6 7 8 9
1 3 5 7
2 4 6 8
128Kbps
data
A CH
B CH
64Kbps
64Kbps
Chapter 1: Introduction
2
To achieve proper operation, the timeslot assignment of
transmit and receive sides must be the same and sequential,
otherwise, the multiplex and de-multiplex feature will not
work reliably.
Figure 1-3: Typical Application of MUX128/2*64
1.2 Data Port Interfaces
The data port of the MUX128/2*64 is DCE and runs at a
fixed rate of 128Kbps in synchronous mode only. At the
receiving side, the incoming data is split equally, bit-for-bit, to
the A and B channels of the G.703/64K interfaces. When
receiving data from the G.703 channels, the data is
recombined to form the outputted 128Kbps stream.
There are 6 interface standards supported by the Data Port.
They are RS-530, RS-449, X.21, V.35, RS-232 and V.36.
The output connector for the Data Port is a standard DB25F
connector. Interface selection is provided by a combination of
DIP switch settings and physical adapter cables. For exact
DIP switch settings and cabling information, please refer to
Appendices A and B respectively.
Chapter 1: Introduction
3
1.3 G.703/64K Interface
The G.703 Interfaces used in the MUX128/2*64 have a
through rate of 64Kbps each and operate in co-directional
mode only. The following will describe co-directional
operation in more detail.
Co-directional
The term co-directional is used to describe an interface
across which the information and its associated timing signal
are transmitted in the same direction (see Figure 1-4).
Figure 1-4: Co-directional interface
This mode is the most popular for point-to-point
applications. All timing modes (recovery, transparent, data
port or internal oscillator) are possible in this mode.
Equipment
Data signal
Timing signal
Equipment
Chapter 1: Introduction
4
G.703 Co-directional Code Conversion Rules
Figure 1-5: G.703 Co-directional Code Conversion Rules Illustration
Step 1: A 64Kbps period is divided into four unit intervals.
Step 2: A binary “one” is coded as a block of four bits “1100”.
Step 3: A binary “zero” is coded as a block of four bits “1010”.
Step 4: The binary signal is converted into a three-level signal.
Step 5: A “Violation” block marks the last bit in an octet.
The next page displays a figure showing the boundaries for
the standard pulse signals for proper operation and
compatibility with other G.703 equipment.
7
1
8
0 1
3 4 5
1
6
1
7
1
8
0 10
1
0
2
0
1
Octet timing
S
t
e
p
5
Step 4
Steps 1 - 3
6
4
k
b
i
t
/
s
d
a
t
a
Bit number
Violation Violation
Chapter 1: Introduction
5
Figure 1-6: Pulse Masks for the 64Kbps co-directional interface.
V
0
V
0
3,12
µ
s
(3,9 – 0,78)
3,51 s
(3,9 – 0,39)
3,9 s
4,29
µ
s
(3,9 + 2,6)
6,5
µ
s
(3,9 + 0,39)
7,8
µ
s
(3,9 + 3,9)
0,5
1,0
7,02
µ
s
(7,8 – 0,78)
7,41
µ
s
(7,8 – 0,39)
7,8 s
8,19
µ
s
(7,8 + 2,6)
10,4
µ
s
(7,8 + 0,39)
11,7
s
(7,8 + 3,9)
1,0
0,5
µ
a)Mask for single pulse
b)Mask for double pulse
Chapter 1: Introduction
6
1.4 Features
Primary G.703 Link
l 2 channels (2x64Kbps)
l Interface: 64Kbps G.703 co-directional
Synchronous mode Data Port interface
l 1 channel DCE-128Kbps: RS-530, RS-449, X.21, V.35, RS-232,
or V.36 Data Port
l DSR constantly ON except in test
l DCD constantly ON
l Data port Loop back (Loop back to DTE)
l Self testing function
1-5 Specifications
G.703 Interface Specifications
l Type: Co-directional 64Kbps
l Line: 4 wires 0.5~0.7mm
l Impedance: 120 Ω (Balanced)
l Clock frequency: 64KHz ±100ppm
l Complies with: ITU G.703 and G.823 (jitter)
l Frame format: unframed only
l Line code: 64Kbps co-directional line code
l Connector: DB9/F (proprietary)
User Data Interface Specifications
l Interface Types: RS530, RS-449, X.21, V.35, RS-232 and V.36
l Data rate: 128Kbps SYNC
l Connector: DB25/F plus adapter cables
Chapter 1: Introduction
7
1.6 Loop back Diagnostics
The MUX128/2*64 features V.54 diagnostic capabilities
for performing local loopback and BERT testing. The
operator at either end of the G.703 lines may test the
MUX128/2*64 in the digital loopback mode. The loopback
function is controlled by push-button switches, located on the
MUX128/2*64 front panel.
When the “Test” push-button is activated, the unit
generates a 511 test pattern, according to ITU, for direct end-
to-end integrity testing. The Error indicator flashes for each
bit error detected. Operation is described in Chapter 2.
1.7 Timing Considerations
Multiple clock source selection provides maximum
flexibility in connecting both the G.703/64K link and user data
interface. The G.703/64K link may be clocked from the
recovered receive clock, from the user data port or from the
internal oscillator.
The MUX128/2*64 has the flexibility to meet the timing
requirements of various system configurations. The timing
mode for the G.703/64K link and the user channel, is selected
by DIP switch setting.
Chapter 1: Introduction
8
E1 link timing
The MUX128/2*64 G.703/64K link receive path always
operates on the receive clock. The MUX128/2*64 recovers
the receive clock from the received link data signal. The
source of the MUX128/2*64 link transmit clock may be
selected by the user. The following four transmit timing
modes are available.
• Recovery timing:
The MUX128/2*64 G.703 link transmit clock is locked to
the recovered receive clock. This is usually the timing mode
selected for network operation.
• Internal timing:
The MUX128/2*64 G.703 link transmit clock is derived
from the internal clock oscillator. This timing mode is
necessary in point-to-point applications over leased lines. In
this case, one MUX128/2*64 must use the internal oscillator,
and the other must operate from the recovered clock.
• Transparent timing:
The MUX128/2*64 synchronous data channel accepts the
recovered G.703 clock and provides the G.703 transmit clock
from the DCE (Transparent timing).
• External timing:
The ETU-01A E1 link transmit clock is locked to the
clock signal provided by the user DCE connected to the data
channel.
Chapter 2: Installation and Operation
9
2.1 General
This chapter provides detailed instructions for mechanical
installation and operation of the MUX128/2*64.
2.2 Site Preparation
Install the MUX128/2*64 within reach of an easily
accessible grounded AC outlet. The outlet should be capable
of furnishing 90 ~ 250 VAC. Allow at least 10 cm (4 inch)
clearance at the rear of the MUX128/2*64 for signal lines and
interface cables.
2.3 Mechanical Assembly
The MUX128/2*64 is designed for tabletop, bench, or
optional rack mount installation, and is delivered completely
assembled. No provision has been made for bolting the
MUX128/2*64 to a tabletop. Rack mounting instructions are
provided in Chapter 3.
2.4 Electrical Installation
2.4.1 Power connection
AC power is supplied to the MUX128/2*64 through a
standard 3-prong IEC connector. (Refer to Figure 2-1) The
MUX128/2*64 should always be grounded through the
protective earth lead of the power cable. The power supply
within the MUX128/2*64 is a switching power type, designed
to operate from any AC voltage, 90 to 250 volts.
Chapter 2: Installation and Operation
10
Figure 2-1: MUX128/2*64 back panel
The line fuse is located in an integral-type fuse holder on
the rear panel. Make sure that only fuses of the required rating
are used for replacement. Do not use repaired fuses or short-
circuit the fuse holder. Always disconnect the power cable
before removing or replacing the fuse.
2.4.2 Rear panel connectors
The MUX128/2*64’s CH-128 DB25F connector, in
combination with various DIP switch settings and adapter
cables, provides for six interface types (RS-530, RS-449,
X.21, V.35, RS-232 and V.36). The G.703/64K line
connectors incorporate DB9F connectors. (Appendix B
provides detailed pin out information on the various interface
connectors).
IEC Connector and
fuse holder
Data Port
Connector
G.703/64K
Connectors
Chapter 2: Installation and Operation
11
2.5 DIP Switches and Jumper Settings
2.5.1. Caution
To avoid accidental electrical shock, disconnect the
MUX128/2*64 power cord prior to opening the cover.
2.5.2. Procedure
a. Turn power OFF. Disconnect the power cord from the AC
outlet.
b. Loosen the thumb screws at the left/right of the rear panel.
c. Remove the PCB assembly.
d. Adjust the DIP switches and jumper as required, according to
the tables in Appendix A.
e. Replace the PCB and tighten the screws.
Referring to the following figure, three DIP switches are
used for configuration and are labeled DSW1 to DSW3. If a
DIP switch configuration is changed while the MUX128/2*64
is in a powered on state, the effect will not be realized until
the unit is power cycled off then on.
The Logic Ground Jumper will connect (CON) or
disconnect (DIS) the MUX128/2*64 logic ground from
chassis ground. Chassis ground is connected directly to the
ground post of the IEC power connector.
Chapter 2: Installation and Operation
12
Figure 2-2: MUX128/2*64 Printed Circuit Board Diagram
CH-128 Data PortG.703/64K (x2)
Loop Back Test Sws.Indicator LEDs
DSW1
DSW2
DSW3
Logic Ground Jumper
Chapter 2: Installation and Operation
13
2.6 Front Panel
The front panel of the MUX128/2*64 provides user access
to the diagnostic loop back push-button switches as well as a
visual reference of activity via LED display.
Figure 2-3: MUX128/2*64 front panel layout
Label Color Description
PWR
green Lights when unit is powered on.
TD
yellow Flashes when data is transmitted from the 128K data port.
RD
yellow Flashes when data is received at the 128K data port.
RTS
yellow Lights when the connected DTE equipment supplies RTS.
DCD
yellow Normally, should be lit during operation.
Ta
yellow Flashes when G.703 A-channel transmits data.
Ra
yellow Flashes when G.703 A-channel receives data.
Tb
yellow Flashes when G.703 B-channel transmits data.
Rb
yellow Flashes when G.703 B-channel receives data.
Err
red Indicates error in BERT or slip in A-B channel delay.
Test
red Lights when any push-button switch is selected.
Table 2-1: Indicator LED descriptions
2.7 Loop Back Operation
The loop back test buttons and LED indicators built into
the MUX128/2*64 allow for rapid checking of the data
terminal, MUX128/2*64 and the G.703/64K lines. Before
testing the operation of the data system equipment and line
circuits, please ensure that all units are turned on and are
configured correctly.
Chapter 2: Installation and Operation
14
Bit Error Rate Tester
When the “Test” push-button is depressed, the internal
pattern generator and pattern tester will be activated and a
511 test pattern will be transmitted out the 64K co-directional
lines. The “Test” LED will light. Referring to figure 2-4, if the
remote MUX128/2*64 unit also has its “Test” push-button
switch depressed, its internal pattern generator and tester will
be activated and its signal will be received by the local unit. In
this configuration, both units and the lines are tested. Both
units will have their “Test” LEDs lit and “Err” LEDs should
be off.
Figure 2-4: Back-to-back BERT testing
Referring to figure 2-5, if the remote MUX128/2*64 unit
is placed into loop back by placing its “Loc ana loopbk”
switch in the depressed position, the 511 pattern will be
returned to the local unit and tested. This will test the local
unit and lines. If there are no errors, the “Err” LEDs should be
off.
Chapter 2: Installation and Operation
15
Figure 2-5: Remote loop back test
In the next example (refer to figure 2-6), a Datacom BERT
tester, such as the HCT-6000 is connected to the
MUX128/2*64 data port. The MUX128/2*64 is placed in
DTE loop back mode by depressing the "DTE loopbk” push-
button switch. This will enable testing of the data port
interface.
Figure 2-6: Data Port BERT
Chapter 2: Installation and Operation
16
2.8 Auto Delay
A feature of the MUX128/2*64 is the auto delay function.
If the two G.703/64K Co-directional signals arrive out of time
at the receivers, the 128K data stream cannot be properly re-
assembled. The delay between channels may be nulled by
manually setting DIP switch 3 or by performing the auto delay
function.
In order to perform auto delay, there must be someone at
each end of the link (refer to figure 2-7).
Figure 2-7: Null Delay Feature
At the local and remote sites, depress the “Test” switches.
Then depress the “Auto Delay” switches on each unit. When
the “Err” LEDs go out, release the “Auto Delay” switches.
The delay both ways has been calculated and saved in each
unit. Now release the “Test” switches. The delay settings have
been saved in EEPROM and are read whenever the unit is
powered up. There is no need to re-calibrate unless the
environment is changed.
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