Section 10 ADVANCED PROBLEM SOLVING
181
A
U
D
I
O
DECODER
OFF
ON
OFF
ON
LOOPBACK
SWITCH
ENCODER
clk
TxD
RxD
RxC
TxC
clk
data
data
audio
audio
V.35
/X.21
I/O
ZEPHYR
SEND
RCV
OFF
ON
OFF
ON
LOOPBACK
SWITCH
This diagram shows the operation of the loopback
function. Note that both sides are affected. The local
audio is looped, as well as the network signal. (This
diagram is labeled for V.35/X.21 I/O, but applies equally
to systems using the internal ISDN TA.)
•
NEAR Loopback
Incoming audio gets coded in the usual manner, sent into the ISDN interface card
and from there looped back to the decoder where it is decoded. Allows a check of
over 90% of Zephyr’s functionality with no ISDN line present.
NOTE: Compatible Xmt and Rcv modes will be required.
These two loopback modes are powerful troubleshooting tools:
•
NEAR loopback can eliminate substantial portions of the Zephyr’s circuitry by
testing to see if the coder and decoder are working. Be sure to test in the relevant
Xmt and Rcv modes to your situation
•
Assuming only one problem, the FAR looback can effectively determine whether the
problems experienced are due to the communications channel(s) or one of the
Zephyrs.
•
While the problem is occurring put first one Zephyr, and then the second
Zephyr into far loopback (after restoring the first to normal status). Be sure to
use compatible Xmt and Rcv modes.
•
If either unit can lock to itself consistently looping through the other unit, then
the communications path(s) cannot be at fault. The unit which can lock to itself
HOT TIP!
Near loopback is only available on units with ISDN interface
card installed . If no ISDN interface is installed “hardware not
available” will be displayed.
Summary of Contents for Zephyr
Page 13: ...Table of Contents 13 SECTION 1 QUICK RESULTS ...
Page 26: ...Section 2 INTRODUCTION 26 This page intentially left blank ...
Page 27: ...Section 2 INTRODUCTION 27 SECTION 2 INTRODUCTION ...
Page 38: ...Section 2 INTRODUCTION 38 This page intentionally left blank ...
Page 39: ...39 SECTION 3 ZEPHYR AT A GLANCE ...
Page 52: ...Section 4 INSTALLATION BASIC OPERATION 52 This page intentionally left blank ...
Page 53: ...Section 4 INSTALLATION BASIC OP 53 SECTION 4 INSTALLATION BASIC OPERATION ...
Page 84: ...Section 4 INSTALLATION BASIC OPERATION 84 ...
Page 85: ...Section 5 ISDN 85 SECTION 5 ISDN ...
Page 105: ...Section 6 NON ISDN NETWORKS 105 SECTION 7 AUDIO CODING ...
Page 118: ...Section 7 AUDIO CODING PRINCIPLES 118 This page intentionally left blank ...
Page 119: ...Section 8 DETAILED MENU REFERENCE 119 SECTION 8 DETAILED MENU REFERENCE ...
Page 157: ...Section 9 REMOTE CONTROL 157 SECTION 9 REMOTE CONTROL ...
Page 176: ...Section 9 REMOTE CONTROL 176 This page intentionally left blank ...
Page 177: ...Section 10 ADVANCED PROBLEM SOLVING 177 SECTION 10 ADVANCED PROBLEM SOLVING ...
Page 196: ...Section 10 ADVANCED PROBLEM SOLVING 196 This page intentionally left blank ...
Page 197: ...Section 11 TECHNICAL INFORMATION 197 SECTION 11 DETAILED TECHNICAL INFORMATION ...
Page 219: ...Section 12 SCHEMATICS 219 SECTION 12 SCHEMATICS ...
Page 221: ...Section 13 MANUFACTURER S DATA SHEETS 221 SECTION 13 MANUFACTURER S DATA SHEETS ...
Page 223: ...Section 14 SPECIFICATIONS WARRANTY 223 SECTION 14 SPECIFICATIONS AND WARRANTY ...
Page 228: ...228 This page intentionally left blank ...
Page 229: ...Section 15 APPENDICES 229 SECTION 15 APPENDICES ...