Appendix B - Functional Operation; Timing; Ground Fault Detect; H2Tu-C-231 List 3F Block Diagram - ADC HiGain H2TU-C-231 List 3F User Manual

Appendix B - Functional Operation

A
PPENDIX
ADC HDSL2 technology provides full-duplex services at standard DS1 rates over copper wires between an
H2TU-C and an H2TU-R, which comprise one HDSL2 system. ADC systems use ADC Overlapped Pulse
Amplitude Modulation (OPAM) transceiver systems to establish a full-duplex, 1.552 kbps data channel between
an H2TU-C and a remotely located H2TU-R.
Figure 36 shows a block diagram of the H2TU-C-231 List 3F. The H2TU-C receives a 1.544 Mbps DSX-1 data
stream from the DSX-1 digital cross-connect interface. The H2TU-C contains a DS1 frame synchronizer
controlled by an 8-bit microprocessor that determines the type of framing on the DS1 stream. The H2TU-C
synchronizes to the type of framing detected. The H2TU-C recognizes SuperFrame (
Extended SuperFrame (ESF).
D
Tip
42
S
XMT
X
43
Ring
1
BRG
LINE
A
Fuse alarm
32
-48Vdc 39
Power Supply
B
15
16
Ground
19
44
Management bus
46
Pre-equalizer
LINE
BRG
D
Tip 1
S
49
RCV
X
50
1
Ring 1
20
Alarms
21
T
IMING
The low loop wander (0.5 UI max) of an H2TU-C, when used with remote units, allows the circuit to be used in
all critical timing applications, including those that are used to transport Stratum 1 timing.
G F
ROUND AULT
The H2TU-C has a Ground Fault Detect (GFD) circuit which detects a ground or a resistive path to ground on any
wire of the HDSL2 loop. This makes the product compliant with the Class A2 requirements of GR-1089.
66
B - F
UNCTIONAL
T1
Framer
Select
Figure 36. H2TU-C-231 List 3F Block Diagram
D
ETECT
June 12, 2002
O
PERATION
HDSL2
Framer
A
-180 5 Vdc
B
(Ground isolated
and ground fault detect)
Microprocessor
RS-232
LEDs
Loopback pushbutton
LTPH-UM-1149-01
), including D4 or
SF
HDSL 2
XCVR
+ _
+
Power
Supply
_
H2TU-C-231 List 3F
Tip
26
HDSL 2
SPAN
27
Ring