Section 150-611-100
Revision 02
Page 4
6. TECHNICAL ASSISTANCE
6.01
PairGain Technical Assistance is available
24-hours-a-day, 7-days-a-week by
contacting PairGain’s Customer Service Engineering
group at one of the following numbers:
Telephone:
(800) 638-0031
(714) 832-9922
Fax:
(714) 832-9924
During normal business hours (8:00 AM to 5:00 PM,
Pacific Time, Monday - Friday, excluding holidays),
technical assistance calls are answered directly by a
Customer Service Engineer. At other times, a
request for technical assistance is handled by an on-
duty Customer Service Engineer through a callback
process. This process results in a callback within 30
minutes of initiating the request.
In addition, PairGain maintains a computer bulletin
board system for obtaining current information on
PairGain products, product troubleshooting tips and
aids, accessing helpful utilities, and for posting
requests or questions. This system is available 24-
hours-a-day by calling (714) 730-3299.
Transmission speeds up to 28.8 kbps are supported
with a character format of 8-N-1.
B. FUNCTIONAL DESCRIPTION
7. FUNCTIONAL OPERATION
7.01
HiGain-2 utilizes PairGain’s 2B1Q VHDSL
transceiver systems to establish one full-
duplex 1.568 kbps data channels between the HLU-
611 and a remotely mounted HRU-612 HiGain-2
Remote Unit.
7.02
A block diagram of the HLU-611 is shown in
Figure 2. The HiGain-2 HLU-611 receives a
1.544 Mbps DS1 data stream from the DSX-1 digital
cross connect interface. The HLU contains a DS1
frame synchronizer controlled by an 8 bit micro
controller that determines the type of framing on the
DS1 stream and synchronizes to it. The HLU-611
recognizes SF (including D4) or ESF framing. When
the data is unframed, the HLU-611 arbitrarily defines
a frame bit.
Figure 2. HLU-611 Block Diagram.
