03/02
Level 2 Troubleshooting
WorkCentre Pro 423/428
2-85
CHAPTER 2 TROUBLESHOOTING
2.3.2.4 D Channel Troubleshooting
The D channel is used to originate, terminate, and clear calls. See the D-channel sequence
for the normal procedure of the D channel.
If the network answers a call, the CALLPROC signal is recorded at REMOTE in the D-
channel protocol (ICM trace) data of the Transmission (Call) side. This indicates normal
communication up to the switching system. If the remote terminal answers the call, the
CONN signal is recorded. This starts communication through the B channels.
In D-channel troubleshooting, "reason for disconnection" is analyzed. The information
element "reason for disconnection" is contained in the DISC, RELCOMP, STATUS, and
PROG signals.
In the ICM trace data of a fax where several communication modules (G4M0, G4M1, G3M0,
G3M1, and other), Layer-3 signals in communication by each module are recorded in the
order of generation. "Call number" is a flag. "Call number" in FIF is analyzed and only the
corresponding communication signals are picked up. "Call number" on the termination side
looks the same in trace data but is actually different because its flag bit is 1. See the
contents of each signal.
Signals used for D-channel communication (Layer-3 network of D channel)
"Type" meaning the information element "message type" is a unique value representing each
signal.
Signal name
Meaning of signal
Type
Description
ALERT
alerting
01
Notice to origination side when
termination side is alerted
CALLPROC
call proceeding
02
Display of start on requested call
setup
CONN
connect
07
Notice of acceptance on
termination side
CONNACK
connect acknowledge
0F
Acknowledgement of response
between terminal and network
PROG
progress
03
Network notice of
interconnection and call
progress
SETUP
setup
05
Call setup request
RES
resume
26
Request for resetting suspended
call
RESACK
resume acknowledge
2E
Reestablishment notice of
suspended call
RESREJ
resume reject
22
Call reestablishment failure
notice
SUSP
suspend
25
Call suspend request
SUSPACK
suspend acknowledge
2D
Call suspend completion notice
SUSPREJ
suspend reject
21
Call suspend failure notice
Signal name
Meaning of signal
Type
Description
USERINFO
user information
20
User-set unique information
DISC
disconnect
45
End-to-end connection recovery
request or notice
REL
release
4D
Information channel and call
number release request after
information channel clearing
RELCOM
release complete
5A
Information channel and call
number release notice
REST
restart
46
Channel or interface initialize
request
RESTACK
restart acknowledge
4E
Initialize completion display
CONCON
congestion control
79
User information flow control
INFO
information
7B
Additional information to send
NOTIFY
notify
6E
Call information notice
STATUS
status
7D
Call status notice from terminal
or network
STATUSENQ
status enqiry
75
Status display message request
Summary of Contents for WorkCentre Pro 423
Page 2: ......
Page 3: ...WorkCentre Pro 423 428 6HUYLFH 0DQXDO...
Page 6: ......
Page 8: ......
Page 9: ...INTRODUCTION...
Page 10: ......
Page 24: ...WorkCentre 423 428 03 02 INTRODUCTION 14 7 Translation of Warnings...
Page 25: ...CHAPTER 1 SERVICE CALL PROCEDURE...
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Page 28: ...WorkCentre Pro 423 428 1 2 CHAPTER 1 SERVICE CALL PROCEDURE 03 02 1 1 Trimming...
Page 31: ...CHAPTER 2 TROUBLESHOOTING...
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Page 76: ...WorkCentre Pro 423 428 2 44 CHAPTER 2 TROUBLESHOOTING 03 02 2 3 Level 2 Troubleshooting...
Page 243: ...CHAPTER 3 IMAGE QUALITY TROUBLESHOOTING...
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Page 273: ...CHAPTER 4 DISASSEMBLY ASSEMBLY AND ADJUSTMENT...
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Page 329: ...CHAPTER 5 PARTS LIST...
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Page 415: ...03 02 5 2 Parts List WorkCentre Pro 423 428 5 85 CHAPTER 5 PARTS LIST...
Page 416: ...CHAPTER 6 GENERAL...
Page 417: ......
Page 456: ...CHAPTER 7 ELECTRICAL WIRING DIAGRAMS...
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Page 476: ...CHAPTER 8 ACCESSORIES...
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Page 535: ...WorkCentre Pro 423 428 8 58 CHAPTER 8 ACCESSORIES 03 02 8 22 Stamp Kit Red...
Page 536: ...CHAPTER 9 BSD Block Schematic Diagram...
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