1
Defining The T1 Terms
Bipolar
A bipolar signal is composed of alternating pulses that both represent a digital logic 1. The positive pulse
is a (+) and the negative pulse is a (-). Zero volts represents a space, or digital logic 0.
Bipolar Violation (or error)
A bipolar error is a digital logic 1 (or mark) that has the same polarity as its predecessor.
NOTE: Every time the system regenerates the signal stream, it corrects any bipolar errors; therefore, it
prevents end-to-end error checking from using bipolar errors.
B8ZS (Binary Eight Zero Substitution)
This is a technique to send an all-zero channel without violating the ones-density requirement (a single
one in each channel and no more than 15 zeros in a row). Voice transmission will not allow an all zero
channel. The system accomplishes B8ZS suppression by inserting a special bipolar error that is
interpreted, not as an error, but an all zero channel. The B8ZS feature replaces the all-zero channel two
different ways. The feature replaces the all-zero channel with the sequence 000 + - 0 - + if the preceding
pulse was a +, and the feature replaces the all-zero channel with the sequence 000 - + 0 + - if the
preceding pulse was -. The + represents a positive pulse, the - represents a negative pulse, and 0
represents no pulse. Set the B8ZS feature with switches SW1–5 and SW1–6.
CAS (Channel Associated Signalling)
The Channel Associated Signalling is the only inbound signalling method currently supported by the
DXPT1 board.
COFA (Change of Frame Alignment)
When switch SW2-6 is off, the green LED on the DXPT1 indicates whether the network source or the
network span caused the last frame synchronization. (This indication disregards the first re-sync at cold
start or a system reset —cold start and reset causes the network source to re-sync.) A COFA occurs if the
network source does a re-sync. The COFA is a diagnostic tool that identifies the source of the loss of
frame synchronization.
CPE/Carrier Equipment
The DXPT1 is normally classified as Customer Premise Equipment (CPE). If you use SW2–2 to
configure the DXPT1 board to use the internal CSU while in the ESF mode, the network may require that
the system be classified as Carrier Equipment (CE). The information packet that the DXPT1 board sends
to the network contains a facility data link (FDL) maintenance message that has a bit in it that provides
this identification.
CRC (Cyclic Redundancy Check)
A method of checking errors from the transmission source to the destination. For T1 operation, CRC
caculates a checksum depending on the data in a frame. The system uses CRC in ESF mode exclusively.
(You must enable CRC with DIP switch SW2-4).
Delay Dial E&M, DID Protocol Type
Once seized by a calling system, the system being called makes A=1 and B=1 until it is ready to receive
digits. When it is ready to receive digits, it makes A=0 and B=0. The system uses a delay dial protocol
when wink protocol timing is not compatible to the network.
Dial Pulse – T1
Dial pulse is a method of sending address digits (numbers) using A and B bits logic bits instead of
sending DTMF tones. Some carriers may not support dial-pulse signalling. While the method is slower
when compared with tones, it requires no DTMF receivers.
IMI89–207
Troubleshooting The DXPT1 Installation
2 – Troubleshooting The DXPT1 Installation
Содержание DXP Plus Series
Страница 1: ...Digital Communications System R ...
Страница 363: ...Automatic Call Distributor Technical Manual R QuickQ DXP ...
Страница 424: ...Automatic Call Distributor System Manager s Guide R QuickQ DXP ...
Страница 500: ...Wrap up Time 1 6 Wrapping Up A Call 4 3 Z Zoom Box A 2 GCA70 271 Index I 3 ...
Страница 628: ...Interconnecting The VMI X Installing And Programming For ExecuMail IMI89 206 Installing And Programming For ExecuMail 5 ...
Страница 677: ...Connecting The Equipment Installing And Programming The OPX X IMI89 209 Installing The OPX X 7 ...
Страница 728: ...DP I I I I and FX Series Digital Communications Systems Understanding The Visual Man Machine Interface COMDlA ...
Страница 1112: ...9 08 8 90 1 13 4 78 3 94 UNIS029 TAB003 PLS page 6 GCA40 130 DXP Plus General Description 11B Telephone Features ...