Edition 29

Syncro Analogue Addressable Fire Control Panel


Syncro AS
Analogue Addressable Fire Control Panel


Syncro View
Local LCD
Repeater Panel

Syncro Open Ended Network

The Syncro network uses a fault tolerant 2-core data loop, permitting up to 64 panels to be networked together, with each Syncro panel acting as a loop isolator and data booster. This hardware configuration provides significant protection against any loss of data for a single open or short circuit in the network cables.

In order to support the replacement of the old Signifire networked systems (which use a single multi-drop RS485 data connection) a new facility was added to the Syncro panels to allow “open ended network” support.
This facility was introduced in Syncro panel firmware 5.70 (Syncro AS V5.20) and is supported in Loop Explorer V4.62 onwards and allows the start and end panels in the open-ended network to be specified.

When this option is implemented, the two panels configured at each end of the network suppress their “network open circuit” fault message reporting. The network data packets are passed backwards and forwards along the open-ended network cable, which results in the following restrictions.

  • Open ended network response is slower than the closed loop configuration
  • It is not possible to transfer site configuration files to remote Syncro panels over an open-ended network

In order to ensure utilise the open-ended network facility, the following rules need to be observed.

  • ALL panels on the network must have firmware that supports the open-ended network installed. If any of the panels are fitted with firmware older than V5.70 (AS V5.20), then the open circuit network fault will be reported.
  • The open ended network fault suppression is NOT supported by Focus and Focus+ panels, therefore these cannot be fitted on an open-ended network configuration

Supplementary information on the Syncro open-ended network is given in Issue 20 of In the Technical Loop and may be downloaded using the following link.

ITTL Edition 20:

Download Syncro Panel update files for
open-ended network support:

Download Syncro Apollo V5.91UK:

Download Syncro Apollo V5.91UK EN Compatible
(older panels without write enable switch):

Download Syncro Hochiki V5.91UK:

Download Syncro Hochiki V5.91UK EN Compatible
(older panels without write enable switch):

Download Syncro AS Panel update files for
open-ended network support:

Download Syncro AS Apollo/Hochiki V5.23UK:

Syncro Analogue Addressable Fire Control Panel


Syncro AS
Analogue Addressable Fire Control Panel


Sigma XT
Control Panel


Sigma CP
Conventional Fire Alarm Control Panel

System Faults on Fire Control panels

Traditionally the “system fault” indication on the older BS5839 pt 4 panels was used to notify that there is a problem with any part of the overall fire control “system”.

With the introduction of the European Standard EN54-2 (Fire detection and fire alarm systems – Part 2: Control and indicating equipment), there was a shift in the terminology such that any fault relating to the system would illuminate a “General Fault” warning indicator. Kentec adopted this terminology on the Solo control panel and have continued to do so ever since.

However, for microprocessor based control and indicating equipment, there are additional requirements under EN54-2 including:

  • Monitoring the execution of the program, to ensure that the panel has not “crashed” or automatically re-started
  • Monitoring the memory contents for both the panel program and the site specific configuration memory, to ensure that the contents are valid and have not changed

In the event of a fault associated with either of these functions, clause 8.5 of EN54-2 advises that a “System Fault” shall be reported.

Therefore a system fault indication on a microprocessor based control panel effectively means that there is a microprocessor or memory related fault.

On the Syncro control panels, a System Fault is reported for the following conditions and additional information:

  • Program execution failure (Watchdog Fault)
  • Main microprocessor hardware failure
  • Panel firmware memory error (ROM Checksum Fault)
  • Site configuration memory error (RAM Checksum Fault)
  • Site configuration memory contents amended
  • Failure for the main microprocessor to communicate with either a loop controller, display controller or general I/O controller (System Fault message in LCD)
  • Failure for the panel to communicate with a configured expansion card on the RS485 expansion bus (disconnected fault will also be shown in the panel display)

For the Sigma CP / Sigma XT panels, the System Fault is reported for the following conditions:

  • Program execution failure / panel CPU reset operated
  • Panel firmware memory error
  • Site configuration memory error
  • Microprocessor hardware failure

The most common occurrence of the System Fault event is due to failure of the panel to execute the panel program. In the majority of cases this is due to external influences on the panel, including excessive mains power spikes and excessive electromagnetic interference from radio systems (paging systems / welding units etc).
When installing microprocessor-based systems, care should be taken to minimise the possibility of external interference affecting the control panel. By using screened cables and ensuring these are adequately bonded to earth, as recommended in the product installation manual, will reduce the risk of system faults in harsh environments.

If you feel a colleague may benefit from receiving In the Technical Loop they can be registered for their own future copy by clicking the following link.

Kentec Electronics Ltd.
Tel: +44 (0)1322 222121 Fax: +44(0)1322 291794