Chapter 2
Operation
Page 2-16
5/02/05
CM 100Base-T System User’s Manual
Performing IF Local Loopback
In IF local loopback, the MOD IF output to the TXU instead connects to the DEMOD IF
input as the right side of Figure 2-9 shows. This isolates the SP from the RF section of
the radio during troubleshooting. Loopback on primary and secondary sides of a
protected radio work separately.
IF Loopback Note
IF local loopback affects customer data, WTU, and SCU traffic. On protected sys-
tems, perform IF local loopback on the off-line side.
To perform IF local loopback, connect a 50-ohm coaxial cable
(PN 3080670A01)
between
the MOD and DEMOD IF connectors (MCX) at the SP shelf.
Performing SYNDES Loopback
SYNDES local loopback identifies problems between the SYNDES and the customer
connection to or from the radio. Set SYNDES local and remote loopbacks to test
individual or all tributaries. LAN A loops back on LAN B and LAN B on LAN A.
Performing SCU Loopback
Set SCU loopback to test the digital or analog service channels. The MUX must be
installed the SP shelf to set SCU local loopback.
SCU remote loopback tests far-end and local radio SCU, MUX, MOD, DEMOD, and RF
sections for problems without interrupting data.The SCU to be tested must be in service
(online) and the remote SCU transmit and receive paths must be on the same unit. The
VF receive output signal is about 3-dB higher than the through-path loss.
Performing WTU Loopback
WTU loopback can test the DS1 or 9600 baud channel. In a remote WTU loopback the
transmit and receive paths must be on the same unit.
Configuring the RF Shelf for RF Loopback (A side)
RF IN
RXU
AGC MON
RF LPBK
LO FREQ
LPBK LO
IF OUT
RX ALM
GND
LO MON
TX LO OUT
OFF
RF OUT
TXU
TX MON
TX LO
TX ALM
TX POWER ADJ
IF IN
LPBK LO OUT
RF
IN
RXU
A
G
C
MON
RF
L
P
B
K
LO
FRE
Q
AD
J
L
P
B
K
LO
IN
IF
OUT
RX
ALM
G
ND
LO
MON
TX
LO
OUT
OFF
RF
OUT
TXU
TX
MON
TX
LO
IN
TX
ALM
TX
P
OWER
AD
J
IF
IN
L
P
B
K
LO
OUT
Configuring the SP Shelf for IF Loopback (A si
P
SU
SCU
ACU
MOD
MOD
DEMOD
DEMOD
MUX SYNDES SYNDES
WTU
DEMOD
MUX
RADIO
RADIO
A
A
IF loopback
cable:
MOD to DEMOD
RF loopback
cable
and attenuators
Figure 2-9. RF and IF Loopback Setup
Summary of Contents for CM7
Page 2: ......
Page 4: ...Page iv 5 04 05 CM7 8 100Base T System User s Manual ...
Page 16: ...Glossary Page xvi CM System Users Manual X Y Z ...
Page 24: ...Microwave Networks CM7 8 100Base T System User s Manual Pagexxiv ...
Page 62: ...Chapter 2 Operation Page 2 18 5 02 05 CM 100Base T System User s Manual ...
Page 64: ...Chapter 3 Module Descriptions Page 3 2 CM7 8 100Base T ...
Page 88: ...Section 3 3 Transmitter Unit Page 3 3 6 CM7 8 System User s Manual ...
Page 96: ...Section 3 5 RF Power Supply Unit Page 3 5 4 CM System User s Manual ...
Page 100: ...Section 3 6 SP Power Supply Unit Page 3 6 4 CM System User s Manual ...
Page 106: ...Section 3 7 Alarm and Control Unit Page 3 7 6 11 18 03 CM 100Base T System User s Manual ...
Page 124: ...Section 3 11 SYNDES Page 3 11 6 CM System User s Manual ...
Page 130: ...Section 3 12 SCU Page 3 12 6 11 18 03 CM 100Base T System User s Manual ...
Page 138: ...Section 3 13 OWU Page 3 13 8 CM System User s Manual ...
Page 150: ...Section 3 15 NMU Page 3 15 6 CM System User s Manual ...
Page 192: ...Chapter 5 Verification Page 5 20 CM System User s Manual ...
Page 194: ...Chapter 6 Maintenance Page 6 2 7 23 03 CM 100Base T System User s Manual ...
Page 224: ...Chapter 6 Maintenance Page 6 32 7 23 03 CM 100Base T System User s Manual ...
Page 226: ...Site Engineering Page 2 CM System User s Manual ...
Page 230: ...Appendix A T I Curves Page A 4 CM7 8 100Base T System User s Manual ...
Page 267: ...Microwave Networks CM System User s Manual PageB 37 ...
Page 268: ...Appendix B QuikLink Page B 38 CM System User s Manual ...
Page 282: ...Appendix D Alarm Codes Page D 6 5 02 05 CM 100Base T System User s Manual ...
Page 290: ...Appendix E Setting Frequency Page E 8 CM7 8 System User s Manual ...
Page 312: ...CM7 8 100Base T System User s Manual Page I 4 Microwave Networks ...