WatchDog (DOGS)

System Attributes

Windows© based application running on diskless solid-state Windows 10 embedded systems:

Interfaces - bespoke customized TN3270 across Ethernet TCP/IP:

Core processes - OfficeCraft software and libraries written in Delphi.


The WatchDog System (DOGS) monitors regular input messages to determine the status of the transmitting system. If it detects a problem it activates visual and audible alarms.

It receives special status messages via a communications controller using a modified form of TN3270, from various elements of a multi-processor mainframe system,

The data contained within the messages, and the precise timing of those messages, determines the DOGS behaviour. This may vary between just updating a display indicating the current time; displaying visual alarm indications; to sounding various audible alarms that can include external sirens; and even issuing pre-determined messages via mobile communications. The DOG status processor can be physically separate from any number of remote display terminals.

Once an alarm condition has been detected, DOG continues to monitors incoming messages to provide detailed timing information to aid operational procedures to ensure a stable system recovery.

Key Technologies Used

Windows Watchdog is designed for compatibility with all versions of Windows©.
Delphi The application is written entirely in Delphi and using OfficeCraft Delphi libraries.
Serial Comms A specialized serial interface used to drive external siren and/or other alarm devices.
Ethernet TCP/IP Ethernet connections are used for mainframe connectivity and for system maintenance and support functions.
TN3270 A specialized custom form of TN3270 using OfficeCraft libraries that was developed to interface to several mainframe computers in a very demanding environment.

System Highlights

The WatchDOG System accurately times incoming messages that are sent from critical applications within the monitored system. Any discrepancy in the timing, or the reception of pre-arranged error statuses causes the DOG to declare an outage.

Depending upon the type of error detected the DOGS responds according to an adapted set of response actions. These can vary from “No Action” through to a full alarm using visual as well as audible alarms including the use of external sirens/klaxons and even pre-determined electronic messaging via mobile communications.

Once an alarm is declared, various timers can be activated to monitor and time recovery activity. Time dependant actions can then be triggered as required by system recovery procedures.

The main display includes a large real time digital clock, this provides not only an accurate time but is also a visual indication of the health of the monitored systems.

DOGS also provides an independent log of system activities and status changes that can be useful for system outage analysis, or for automated determination of system reliability.

WatchDog is currently used by the National Air Traffic Services (NATS) operational flight data processing systems.