User Manual
Table Of Contents
- 1. Getting started
- 2. Introduction
- 3. Preparation
- 4. About the terminal
- 5. Mounting and installing the terminal
- 6. Connecting to the terminal
- 7. Managing the terminal
- 8. Configuring the terminal
- 9. Configuring the traffic interfaces
- 10. Cross Connections
- Embedded cross connect switch
- The Cross Connections application
- The Cross Connections system requirements
- Installing the Cross Connections application
- Opening the Cross Connections application
- The Cross Connections page
- Setting the terminal's address
- Management and user ethernet capacity
- Setting card types
- Getting cross connection configuration from the terminals
- Creating cross connections
- Sending cross connection configuration to the terminals
- Saving cross connection configurations
- Using existing cross connection configurations
- Printing the cross connection configuration
- Deleting cross connections
- Configuring the traffic cross connections
- Cross connection example
- Symmetrical Connection Wizard
- 11. Protected terminals
- 12. In-service commissioning
- What you will need
- Checking the antenna polarization
- Visually aligning antennas
- Accurately aligning the antennas
- Synchronizing the terminals
- Checking performance
- Checking the receive input level
- Checking the fade margin
- Checking long-term BER
- Bit Error Rate tests
- Additional tests
- Checking the link performance
- Viewing a summary of the link performance
- What you will need
- 13. Maintenance
- 14. Troubleshooting
- 15. Interface connections
- 16. Alarm types and sources
- 17. Country specific settings
- 18. Specifications
- Ethernet interface
- QJET Quad E1 / T1 interface
- Q4EM Quad 4 wire E&M interface
- DFXO Dual foreign exchange office interface
- DFXS Dual foreign exchange subscriber interface
- QV24 Quad V.24 asynchronous data interface
- HSS Single high speed synchronous data interface
- External alarm interfaces
- Auxiliary interfaces
- AC Power supply
- DC Power supply
- Power consumption
- MHSB protection
- Ethernet interface
- 19. Product end of life
- 20. Abbreviations
- 21. Acknowledgments and licensing
- 22. Commissioning Forms
- 23. Index

Configuring the traffic interfaces | 92
Line Termination Impedance
The line termination impedance (Zt) is the impedance seen looking into the DFXO or DFXS interface.
The line termination impedance is not
the same as the hybrid balance impedance network (Zb) but
can be set to the same value.
Changing the DFXO / DFXS impedance setting on the Aprisa XE changes both the line termination
impedance and the hybrid balance impedance to the same value.
Hybrid Balance Impedance
The hybrid balance impedance (Zb) is the impedance network on the opposite side of the hybrid from
the DFXO / DFXS line interface. The purpose of this network is to balance the hybrid to the impedance
presented to the DFXO / DFXS line interface.
Changing the DFXO / DFXS impedance setting on the Aprisa XE changes both the line termination
impedance and the hybrid balance impedance to the same value.
Transhybrid loss
Transhybrid loss is a measure of how much analogue signal received from the remote terminal is
passed across the hybrid and sent to the remote terminal.
The transhybrid loss is maximized when the hybrid balance impedance matches the impedance
presented to the DFXO / DFXS line interface. An optimized hybrid minimizes circuit echo.