Telos TWOx12 - Using Loop Modes for Troubleshooting; Troubleshooting ISDN Problems

TELOS TWOX12 USER’S MANUAL
TECHNICAL DATA & TROUBLESHOOTING
CHAPTER 8 148
Connected All signaling is complete - the voice channel is available for use. OR
POTS interface is “off-hook” and loop current has been detected.
Using Loop Modes for Troubleshooting
Loop Mode
This item allows the Telos TWOx12 to loop audio through the system.
• Off
This is the normal operating mode. None of the loopback paths are turned on. Studio
Input is sent as send audio, and caller audio is presented at Studio Out.
• Studio
This loops the AES/EBU input (and analog signal inputs after Analog-to-Digital
conversion) back to the AES/EBU output (and analog output via the Digital-to-
Analog converter). With this mode engaged you can make signal to noise, THD, and
frequency response measurements through the system to check the input and output
stages.
8.4 Troubleshooting ISDN Problems
Condition: Can’t Get ISDN “
Ready”
Indication
First try disconnecting the ISDN circuit(s) in question and waiting a full 60 seconds (leave
the TWOx12 on) and then reconnect the circuit(s).
What kind of ISDN do you have, and is the TWOx12 set to match it?
The telephone company should have given you the ISDN protocol when the line was ordered.
If you find yourself in the field without this information, it is usually possible to piece
together what you need.
• If you are given SPIDs, you probably have Natl ISDN 1 or DMS 100 for your ISDN
protocol. One SPID means one channel was activated, rather than the usual two. You
won’t be able to make a stereo connection.
• No SPIDs and only one phone number generally means AT&T PTP protocol. You
must not have SPIDs entered if using this protocol or Wait will be displayed.
• In Europe, you have either ETS300 (EuroISDN) or the local protocol, such as ITR6
in Germany or VN2 in France. The TWOx12 only works with ETS300.
In the case of Natl.I-1 or 2, and DMS-100 carefully verify that you have the correct SPID
from the Telco, and that you have properly entered it into the system. It must be correct in
order for anything to work! We’ve seen a few cases where it was given incorrectly by Telco
personnel, so it might be a good idea to re-check with them if things are pointing in this
direction.