USER
MANUAL
MODEL IM 1/F
G. 703 Interface Module
Part# 07MIM1F-B
Doc# 090071UB
Revised 08/10/99
SALES OFFICE
(301) 975-1000
TECHNICAL SUPPORT
(301) 975-1007
2.0 GENERAL INFORMATION
2.3.1 APPLICATIONS AND ASSOCIATED TIMING
Thank you for your purchase of this Patton Electronics product.
This product has been thoroughly inspected and tested and is warrant-
ed for One Year parts and labor. If any questions or problems arise
during installation or use of this product, please do not hesitate to con-
ton.com.
There are two typical applications that result in two different timing
modes for the G.703 interface. These are illustrated below.
Timing of Application 1: Network Loop Extension
In this application, the network supplies the timing for the entire
system. The first G.703 recovers the timing. It has to smooth the
clock before it supplies the clock (XCLK1) and the data (TXD1) to the
first modem transmitter, so it can directly use the clock. The Rx of the
second modem recovers the clock and presents a “jittery” clock
(RXCLK1) and data (RXD1) to the second G.703’s transmitter. This
transmitter has to smooth the clock before it uses the clock to transmit.
2.1 FEATURES
• Designed for use with Patton Electronics Access products that
TM
receive QuickConnect Modules and support 64K or 128K syn-
chronous rates.
• Provides 64K codirectional interface compliant with the G.703
electrical specs.
• Offers a single Tx/Rx interface with a standard RJ-45 connector as
specified in TBR 14.
• Option to work in two timing modes: Clear channel or octet timing.
• Complies with ITU/CCITT G.823 (Control of Jitter).
• Point-to-point distance up to 4,000 feet (1219m) using 24 AWG
twisted pair.
The Rx of the second G.703 recovers the timing and clocks the
data into a FIFO. The Tx of the second modem takes its recovered
clock and sends it (TXCLK1) to the G.703 FIFO for data (TXD1). The
Rx of the first modem recovers the timing and clocks (RXCLK1) the
data (RXD1) into a FIFO. The Tx of the first G.703 uses the first
G.703’s recovered clock and sends it to the FIFO for data.
G.703 TX
SMOOTHS
RX MODEM
CLOCK
HOST
MODEM -
RECOVERED
TIMING
G.703 INTF-
MODEM
TIMED MODE
• Made in the U.S.A.
2.2 DESCRIPTION
RX
TX
TX
RX
TX
FIFO
FIFO
The Patton Model IM 1/F Interface Module converts data from a
64K G.703 network into a Transistor-Transistor Logic (TTL) compatible
signal that is transported by the PE 1090 or 1092 Modem or a similar 2
or 4 wire short haul modem that has identical pin outs and edge con-
nector style (see note, below). The G.703 network provides a 64K co-
directional three level signal using either octet timing or clear channel
mode. The IM will detect and pass either octet timing (preserving byte
integrity over a 128kbps modem link) or clear channel timing (without
byte integrity preservation) over a 64Kbps modem link. The IM is
capable of handling either network timing or modem timing, thereby
realizing network extension or network replacement configurations.
Clock jitter is attenuated according to G.823.
G.703
RX
CSU
DTE
SECOND MODEM
FIFO
RX
TX
RX
RX
2 or 4 Wire
G.703
FIFO
TX
TX
2.3 SYSTEM DESCRIPTION
SMOOTHED
This section describes the features that the entire system (G.703
interface, combined with the modems) will support.
NETWORK
FIRST MODEM
HOST
G.703 INTF-
NETWORK
TIMED MODE
MODEM -
INTERFACE
(EXTERNAL)
TIMING
NOTE: The “smoothed” clocks referred to in this section indicate
that a phase locked VCO is used to create a jitter free clock that is
locked to a source clock.
Figure 1. Network Loop Extension Configuration
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The first G.703 interface is in Network Timed mode. The second is in
Modem Timed mode. See Figure 1 above.
Both G.703 interfaces are in Modem Timed mode. See Figure 2
above.
Timing of Application 2: Network Replacement
2.4 TIMING MODE SELECTIONS
The first modem uses an internal timing source and supplies the
timing for the entire system. The first G.703 recovers the timing and
clocks the data into the FIFO. The Tx of the first modem takes its
internal clock and sends it (TXCLK1) to the G.703 FIFO for data
(TXD1). The Rx of the second modem recovers the clock and pres-
ents a “jittery” clock and data to the second G.703’s transmitter. It has
to smooth the clock before it uses the clock to transmit.
Based on the timing arrangements and clock sources mentioned
above, there are two timing modes in which the interface can work.
These two modes select the clock sources mentioned above and
determine which clock gets smoothed.
Network Timed - This sets the interface to pass the smoothed
recovered timing to the modem as XCLK1, with the Rx data as TXD1,
and also to the G.703 Tx side.
The Rx of the second G.703 recovers the timing and clocks the
data into a FIFO. The Tx of the second modem sends the second
modem’s recovered clock (TXCLK1) to the G.703 FIFO for data
(TXD1). The Rx of the first modem uses its internal clock (RXCLK1) to
send data (RXD1) into the FIFO. The Tx of the first G.703 smooths
the first modem’s recovered timing and sends it to the FIFO for data.
Modem Timed - This sets the interface to use the modem’s Tx
timing (recovered or internal source) to send the Rx data (as TXD1) to
the modem and to smooth the modem’s recovered timing for transmit-
ting on the G.703 Tx side.
G.703 TX
SMOOTHS
RX MODEM
CLOCK
HOST
MODEM -
RECOVERED
TIMING
G.703 INTF-
MODEM
TIMED MODE
In both cases, the transmitter uses the smoothed clock.
2.5 OPERATING MODE SELECTIONS
TX
RX
TX
FIFO
FIFO
RX
TX
There are two data modes in which the interface passes data and
timing:
G.703
RX
Octet Mode - Data is passed at a 128K rate. This mode pre-
serves the byte integrity associated with Octet timing. The Octet tim-
ing frame is embedded in the data.
CSU
DTE
SECOND MODEM
G.703 TX SMOOTHS
RX MODEM CLOCK
Clear Channel Mode - Data is passed at a 64K rate. This does
not preserve the byte integrity associated with Octet timing. Instead,
an Octet timing alarm (on or off) is passed over the modem similar to
the way signaling leads are passed.
FIFO
TX
RX
RX
RX
TX
G.703
2 or 4 Wire
FIFO
TX
SMOOTHED
CSU
DTE
HOST
FIRST MODEM
G.703 INTF-
MODEM
TIMED MODE
MODEM -
INTERNAL
TIMING
Figure 2. Network Replacement Configuration
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3.0 CONFIGURATION
4.0 INSTALLATION
The Model IM 1/F is equipped with four DIP switches that allow
configuration of the unit to match your application. These DIP switch-
es are located on the top side of the module. Refer to Figure 3 below
for a description of the DIP switches location on the module and a
summary table detailing their settings.
Once the Model IM 1/F is properly configured, it is ready to install into a
PE 1090 or 1092. This section tells you how to properly connect the Model IM
1/F.
4.1 CONNECTION TO THE MODEM’S SERIAL PORT
TM
The QuickConnect module has a 50 pin card edge connector on
4
3
2
1
Off
On
one side and an RJ-45 connector on the other side. Figure 4 shows
TM
how a QuickConnect module plugs into the back of a Patton
Electronics Model 1090 or Model 1092.
ne
Figure 3: Top Side of IM 1/F, Dip Switch Location
Interface Port
The following table defines the possible configurations of the IM
1/F using the configuration DIP switch, S1. Factory defaults are in
bold-face.
1 ON
0 OFF
Switch
On
Off
Figure 4. Installation of Model IM 1/F Plug-in Serial Interface Module
S1-1
S1-2
S1-3
S1-4
Modem Timed
Not Used
Clear Channel Mode
Normal Operation
Network Timed
Not Used
Octet Mode
Reserved for Factory
Use
4.2 CONNECTION TO THE TWISTED PAIR INTERFACE
The Model IM 1/F supports communication between itself and a
G.703 PCM network at distances up to 4,000 feet (1219m) using 24
AWG twisted pair cable.
NOTE: S1-4 must be “On.”
To function properly, the Model IM 1/F requires two twisted pairs
of metallic wire. These twisted pairs must be unconditioned, dry metal-
lic wire, between 22 and 26 AWG (0.4mm to 0.6mm diameter solid
conductors). Higher gauge wire may limit distance. Flat modular tele-
phone type cable is not acceptable.
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APPENDIX A
The RJ-45 connector on the Model IM 1/F twisted pair interface is
pre-wired according to the signal/pin relationships shown in Figure 5
below.
SPECIFICATIONS
Applications:
Connector:
Interface:
64K G.703 codirectional PCM network
extension or network replacement
1 (RX Tip)
2 (RX Ring)
3 (N/C)
4 (TX Ring)
5 (TX Tip)
6 (N/C)
1
2
3
4
5
6
7
8
Symmetrically balanced pair, 4 wire RJ-45
female
Entire module plugs into Patton Electronics
1090 or 1092 Modem
7 (N/C)
8 (N/C)
Operating
Modes/Speed:
Supports octet mode or clear channel mode
Co-directional timing, Rx recovered:
64Kbits + 500ppm
Pin
Signal Name
Direction
Function
(In reference to IM)
Octet Timing auto detect on receiver
1
2
RD(T)
RD(R)
IN
IN
Receive data in (tip)
Receive data in (ring)
Not used
Line Coding:
AMI with block violation for octet timing
3
4
5
6
TD(R)
TD(T)
OUT
OUT
Transmit data out (ring)
Transmit data out (tip)
Not used
Timing Modes:
Supports network timing mode or modem
timing mode
7,8
Not used
Transmit Level:
2.0V differential, into 100 Ohms, nominal
Load Impedance:
Input Signal Level:
Jitter Performance:
120 Ohms
0 to -10dB
Figure 5. Model IM 1/F Twisted Pair Interface Signal/Pin Relationship
Important: Connection of the Patton G.703 IM to a CSU
CTR 14, G.823. <0.05UI jitter for network
extension applications
DTE requires a crossover twisted pair cable. Connection of the G.703
IM to a PCM network requires a straight through twisted pair cable.
If you need more assistance with cable selection and preparation, contact
Patton Technical Support at (301) 975-1007. Additional assistance at
Isolation:
2000 VRMS isolation, transformer coupled
TM
PC Board
Dimensions:
2.950” X 3.200”, QuickConnect Interface
Module size
Compliance:
FCC Class A
EN 50081-1, Emissions
EN 50082-1, Susceptibility
Designed for compliance with CTR 14
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