ISBF Broadband Filter

Excelsus® Z-Blocker ® Z-A431EU Alarm Panel DSL Filter

The Z-A431EU alarm panel DSL filter is designed to eliminate the interference that occurswith alarm systems and ADSL service, and that often prevents proper operation of alarm panel features.

Alarm dealers and service providers have taken various approaches to solve this problem, such as:

  • Installing a splitter or separate phone line, which is more costly and time consuming than installing an alarm filter.
  • Installing a standard DSL filter at the alarm panel, which could prevent the alarm panel from seizing the line to dial out in an emergency if it is cut.

None of these approaches provide an inexpensive and straightforward solution to the problems created by the coexistence of DSL service with an alarm system.

Designed specifically for alarm systems, the Z-A431EU isolates high frequency ADSL and HPN (Home Phone Network) signals from low frequency voice and data calls. This enables simultaneous full functionality of both the alarm panel and DSL service. The Z-A431EU has three filters: one plain old telephone service (POTS) loss-pass filter to protect the alarm panel from ADSL interference, a seconds POTS low-pass filter to protect ADSL from impedance changes in the alarm panel, and a high-pass ADSL filter to ensure ongoing ADSL service, even during an alarm call.


The Z-A431EU is the first alarm panel DSL filter that is compatible with the new European technical standard EN 50131 for alarm/ intrusion systems.



  • Supports the line seizure and cut-line protection features of the alarm panel, providing reliable dial-out in case of an emergency or cut line.
  • Provides uninterrupted ADSL/HPN communication during alarm panel incidents.
  • Surge protection circuitry for extra customer premises equipment protection from lightning surges and power crosses.
  • Two pass-through lines for line monitoring and signalling by the alarm provider.
  • Compatible with most major alarm panels used in residential and small business applications.
  • Compatible with EN standard 50131 for alarm/intrusion systems.
  • CE Mark certified.



Interface Solutions UK LTD

Interface Solutions UK LTD