
150-231-184-05, Revision 05
Overview
HLU-231 List 8D
October 25, 1999
3
HiGain Doubler Applications
For applications without doublers, the HLU-231 is directly connected to the HRU by the two HDSL cable pairs.
The HLU-231 List 8D is compatible with all HiGain HRUs.
For doubler applications, one to four doublers can be used in the HDSL loops between the HLU and HRU.
•
The HLU-231 List 8D can power three doublers and a remote unit (HRU-402 or HRU-411) for a total of four
spans.
•
If the HRU is locally powered, the HLU can power up to four doublers for a total of five spans.
Personal Communications System Applications
The HLU-231 List 8D is required for PCS applications that use the HRU-411. The HRU-411 has an onboard
130 V, 8.5 W power supply that can power the 200 mW PCS remote radio ports. The HLU recognizes the
HRU-411, if the Customer Premises Equipment (CPE) Power switch is set to ON, and performs the following two
functions required by the HRU-411 to bring up the National Electric Code (NEC) radio port:
•
Increases the HDSL line voltage to its high ±112 V level with the PWRF option set to AUTO.
•
Enables HRU-411 to turn on its 130 V radio port supply.
These extended ranges are only available when using the HDU-409, HDU-404 or HDU-407
micro-doublers with the HRU-411 or HRU-402. The HDU-451, HDU-439 and HDU-437 cannot be
used in circuits with more than two doublers in any line or local power system. For compatibility
guidelines on mixing newer doublers with older HRU and HLU models, refer to
Circuit Deployment” on page 58
For additional information about associated HiGain equipment, refer to the respective HiGain
technical practice (see
“Appendix D - Product Support” on page 60
).