Kestrel Emergency Telephone System (KETS)

Transcription

1 Kestrel Emergency Telephone System (KETS) 1. Overview of the Kestrel KETS system The Kestrel Emergency Telephone System (KETS) has been designed by Kestrel to provide a practical product alternative to the current PETS system used within Network Rail for Automatic Half Barrier crossings. The system has concluded its live testing by Network Rail and the PADS number to complete the approvals is awaited. KETS is an omnibus type design and has been devised as an integral part of the Kestrel Hawk Concentrator system. It is important to appreciate that the KETS design provides an alternative solution to the requirement for Public Emergency Telephone System (PETS) applications. It is not a replacement for the PETS product, but is a totally different design meeting the same standards. 2. System description The control end of the system requires a standard Hawk to be fitted with a KETS line interface board for each line serviced. The outstation requires intelligent KETS telephone unit(s) to interface to the line pair at the particular level crossing via a Kestrel Line Termination Unit. The complete KETS system is line powered and therefore also UPS backed from the main Hawk Concentrator. Because of the need for an approved weatherproof telephone at the outstation the decision was made to provide this unit in association with GAI-Tronics Ltd. As a result the mechanics

2 of their Titan weather resistant telephone is utilized, with the specialised internal electronics manufactured by them, under license from Kestrel. For further details see : The Kestrel Hawk KETS design provides a full and effective replacement for the PETS system such that, for all practical purposes, the working methods are identical. The advantages of the Kestrel KETS system are: 1. Cost 2. Simplicity of installation 3. Simplicity and speed of operation 4. Identical operation to the PETS system 5. Ability to work over exceptionally noisy circuits 6. Optional facility to interface to other PABXs 7. No outstation power required (Fully line powered with 12 hour UPS) 3 Hardware design This system extension to the Hawk design consists of one additional line board plus the GAI- Tronics weatherproof Titan KETS phone units. One line board accommodates one KETS circuit supporting up to four outstation telephone units. The Hawk wall unit will accommodate up 7 or 14 such line boards in the same way as for the existing products. They will also operate in conjunction with all the current standard Hawk line interface boards. 3.1 Hawk KETS Line board The KETS line board meets the same requirement specification as the other Hawk line boards in that it may be plugged into any board slot in the system. There are two variants of the board which will meet the two versions of the PETS system requirement : (a) Common interface to the KETS pair for the purposes of keyboard presentation (b) Selective interface to the KETS pair to allow each individual outstation telephone to be separately presented on the keyboard. (See also Hawk omni product)

3 I The board is designed to operate within the Hawk in the same way as the present Hawk PETS line interface board. This includes being able to present alarms and status on the Hawk ETS display unit. When required, the ETS display unit will present information from both an KETS circuit and a PETS circuit at the same time. 3.2 Outstation telephone The outstation telephone is based on the GAI-Tronics TITAN weatherproof telephone unit. The telephone board is a totally new design providing all the facilities needed to operate as a secure telephone on the KETS pair. It has been designed by Kestrel and Gai-Tronics manufacture it as an integral part of their new Titan KETS telephone unit. The software design of the outstation board is such that there is no requirement for manual addressing of the telephone for identification purposes. The software automatically identifies the correct address on initial power up. When required, for specific applications, manual addressing by links is available as standard. For further details see : 4 Operational information 4.1 Signaller So far as the Signaller is concerned the control of the circuit is identical to the Whiteley PETS as installed on a Hawk system There are normally two keys associated with each KETS line on a Hawk Concentrator system: 1. The line key 2. The Fault key

4 These act in identical manner to the PETS circuit(s) on the Hawk. An incoming call will be presented on the control desk as for all other circuits. It is answered by lifting the handset and pressing the relevant key as normal. During a call in progress other outstation attempts to make a call on the same KETS circuit will be indicated by intrusion tone as the for current PETS system. Clear down of the call will be done at the control end by re-pressing the line key or replacing the handset on hook. Calling out simply requires the control desk handset to be offhook and the line key to be pressed. There is a difference here compared with the PETS system in that the call will cause ringing at the outstation, within 0.6 seconds of the key being pressed. 4.2 Outstation operation At the outstation the caller will firstly open the door. The instruction label will be illuminated, although this will only be seen in twilight or dark conditions. (To avoid excessive line current the light will extinguish after approximately 30 seconds. This time is factory settable). The handset must then be lifted off when dial tone will be heard. Pressing the call button will set up the call and result in ring tone being heard in the earpiece. When the call is answered the ring tone will clear as for a normal telephone call. At the end of the call the handset should be replaced and the door closed. If a ring back occurs (the signaller calling back) a high pitched loud telephone type of ring cycle will be heard at all phones. The call is answered by lifting any one handset as in normal telephone systems, or, if the handset is already off hook, by pressing the Call button. It important to note that, if a call is made from the Signal Box, the outstation phones will ring even if one, or more, handsets are offhook. 5 Faults and Alarms All faults associated with the KETS circuit are presented on the Status and alarm unit: Each Status and Alarm unit presents information for up to two KETS circuits.

5 In the following table the first column refer to the ETS display unit. The second column indicates the alarm as presented at the Hawk wall box. ETS Display unit Hawk Alarm Comments COMMS FAIL COMMS FAIL Line failure between Signal box and level crossing EQUP T TELEPHONE Loss of one, or more KETS o/s telephones ((but not all) FAULT FAULT VANDALISED TELEPHONE Probable loss of a handset FAULT ONE OFFHOOK none Not necessary for KETS as the outstation is still active and can be called from the Signal Box MULTI OFFHOOK None Not necessary for KETS as the outstation is still active and can be called from the Signal Box