Alarms - ADC HiGain HLU-200 User Manual

150-200-114-03, Issue 03
tip-ring reversals and for loop swaps caused by pair reversals. The HiGain system allows for tip-ring or pair
reversals, but does not tolerate split pairs. By synchronizing to the Frame Sync Word (FSW) of each loop, the
framer can reconstruct the original 1.544 Mbps DS1 stream from the payloads of the two HDSL loops. The
CRC fields on the HDSL streams allow the HLU-200 List 1D to determine if errors are present on the loop due
to excessive impairments on the HDSL pairs, or due to excessive impulse or crosstalk noise.
The framer removes data link messages from the HDSL loops and passes them to the microprocessor. This
mechanism allows operations messages and status to be exchanged between the HLU-200and the HRU-412
remote unit.
The reconstructed HDSL data is buffered in a first-in-first-out (FIFO) buffer within the framer. A frequency
synthesizer in conjunction with the FIFO regulates the output bit rate and reconstructs the DS1 clock at the
exact rate received from the remote end. The HiGain system operates at DS1 rates of 1.544 Mbps with up to
±200 bps of offset.
The HLU-200 List 1D line power supply converts the -48 Vdc battery to a -130 Vdc (-200 Vdc for doublers)
which provides simplex power feed on the two HDSL line interfaces.
A female 9-pin, DB-9 RS-232, is provided on the front panel connector (see Figure 4). This connector provides
asynchronous access to the HiGain system maintenance, provisioning and performance monitoring firmware.
The port is configured as DCE with 8 data bits, 1 stop bit and no parity. Operator interaction with the firmware
is from an ASCII terminal or a personal computer with asynchronous communication software. Pressing the
spacebar several times enables the HLU-200 to automatically match the terminal line baud rate, from 1200
baud to 9600 baud. Figures 9 through 16 show the menu selections available from the terminal. Table 17
defines the status menu terms. Table 18 defines the glossary of HiGain terms used in the System Status Screen.

Alarms

The following alarms are detected and reported to the Litespan microprocessor via the Alarm signal from the
HLU microprocessor to the Litespan processor as shown in Figure 3. They also cause the HDSL LED to flash
red.
1. ALRM LOSW: Either of the HDSL loops lost sync
2. ALRM RLOS: Loss of HRU DS1 input signal
HLU-200 List 1D
HLU
TD (Transmit Data)
DCE
RD (Receive Data)
GND
Female Male
DB9
Figure 4.
DB-9 RS-232 I/O Pinouts.
November 22, 1996
Terminal
DTE
DB9
Terminal
DTE
DB25
17