ESA11- IR ELECTRONIC INTERLOCKING SYSTEM
But keeping in view of the modern technology, the advantages of controlling the train movements in the stations yard through VDU based operating cum indication panel far outweigh that of controlling the train movements in the station yard through Domino type operating cum indication panel.
Some of the advantages available are (when VDU based operating cum indication panel is used for the ESA11-IR system):
Alterations:
No need for physical alteration and re-wiring to the Operating cum Indication panel when Yard layouts are modified or changed due to operational requirements. All alterations are done in software. It is easy to carry out alterations in a working panel. All needed alterations are done off line and the modified yard layout SW is loaded in less than 5 minutes.
Occupation of Space:
VDU panel occupies less space.
Electro-mechanical Counters/buttons/keys etc:
No need for provision of any buttons, keys or electro-mechanical ‘counters’ for logging certain station master operations, as such information is logged automatically in the built-in data logger. (In a Domino Panel, a simple button stuck situation brings the complete panel operations to a standstill).
Yard display colours:
In a traditional Domino Panel, before any route is selected the track indications are blank on the panel. And when the route is selected the track indications show ‘white’ (yellow in case of LED’s). And when the train is in the section or track is occupied the track indications turn to ‘red’ colour. And when the route release takes place, after the train movement is completed the track indications become blank once more.
In VDU based panel operation, the station master has the advantage of seeing the unoccupied & unselected tracks in ‘Grey’ colour & as soon as the Route is selected, the track indications turn to ‘green’ colour & when the train has entered the section the track indications go to ‘red’ colour & when the route release takes place after completion of the train movement, the track indication return back to ‘Grey’ colour.
Much more & intelligent information can be made available to the operator on theVDU panel. For Example: Train Routes on VDU are shown in green Colour & the SHUNT Routes are shown in ‘white’ colour. Calling ON routes are shown in Yellow colour.
SM Key:
In conventional Domino panel only one SM’s key is provided but in VDU panel each operator or SM can have his own ‘smart card’ & separate ‘data log’ will be maintained about each operators actions.
Advantages of a VDU panel (when compared to Domino Panel)
The VDU panel is more reliable as there is no necessity to change the fused bulbs etc. Less power consumption
More aesthetic & elegant
Additional facilities on VDU panel (for ESA11-IR systems):
Provision of Additional information on the VDU panel is possible for better convenience to the operator/station master, which is not possible on the DOMINO type panel.
Train Numbering:
Train numbers can be assigned to the incoming or outgoing trains & the operator can follow the movement of the trains by train numbers which move along with the movement of the train
Warning labels:
Warning label/s can be established on any track circuit. Whenever the on duty SM tries to set a route, the warning label/s will appear, which the on duty SM has to acknowledge, for enabling the route setting operation to continue.
Traffic Closure labels:
Similarly ‘traffic closure’ label/s can be set on any track circuit (for example ‘rail crack’). Whenever the on duty SM tries to set a route, the ‘traffic closure’ label/s will appear, which the on duty SM has to acknowledge, and then the system will display a ‘risk page’ which the on duty SM must acknowledge by a digital signature, for enabling the route setting operation to continue.
Clamping of points:
A ‘software lock’ can be established on any point machine, which prohibits the operation of that point. Whenever TSL (Temporary Single Line) mode of working is adopted, the SM can establish a ‘software lock’ on the points required to dispatch a train, which greatly reduces the time required to dispatch a train under TSL working mode.
Auto signal working:
At the click of a mouse each signal can be converted into an ‘auto signal’ i.e. the whole yard can be converted into an ‘auto territory’.
Pre-setting of routes:
There is provision to pre-set train routes and as soon as the previous train route is completed the computer fetches the preset route and establishes the route and so on till all the preset routes are exhausted.
Absence of AT supply indication:
Whenever AT traction AT supply fails, the tracks which do not have the traction AT supply, are indicated (enveloped) in dark blue colour, drawing the attention of SM immediately.
Macro Setting:
For large yards where complex route setting is possible (from A to D via B & C routes), the SM (each) can set his own macro, to quickly establish the route by two clicks, instead of the normal 4 clicks.
Domino type Operation cum Indication Panel:
Information about Domino type operation cum indication panel is not being presented here as railways are very familiar with this type of equipment- except that it conforms to IRS/S/36 specification.
VDU Based Operation cum Indication Panel:
The ESA11-IR electronic Interlocking equipment is controlled through two or more VDU’s. One VDU is used for displaying the yard layout, and the second VDU is used for displaying Text based information. Bigger Yards may require more than One VDU for displaying the complete Yard.
ESA11- IR ELECTRONIC INTERLOCKING SYSTEM
Note: Above is a example of a typical Control panel with 2 VDU’s for geographic display cum control purposes.
Normally one Colour VDU is used for Graphic Display & one Monochrome VDU is used for Text Based information Display.
A typical yard display in graphic form for Display Typical PRV- Executive Computers & control through GUI based graphic symbols
The VDU based control panel is controlled by a computer terminal called ‘ZPC’. The VDU panel allows the traditional control of the movement of trains in the station yard and realises the interlocking functions. Normally for a way side station ONE VDU is sufficient to display the complete yard (upto a station with 6 to 8 lines). In case the yard is bigger & also if geographical control of a yard is proposed, then only second VDU is added A maximum of 3 colour VDUs along with 1 monochrome VDU is possible for one station yard or alternatively you can use 4 colour VDU’s without any monochrome VDU. Provision is also made to scroll the yard from left to right.
The VDU panel can be configured as:
(a) to have full 100% functional capability of the complete station yard
(b) with geographic limitations of functions i.e you can control part of the yard (c) with very many limited functions
(d) with combined limitation i.e both geographic and functions
Standby VDU:
Provision exists (optional) to have a standby colour VDU (monitor) in case the main VDU fails due to any reason
Operation from a VDU Panel:
In Domino type operating cum indication panel push buttons are used for setting a route or any other authorised movement. In VDU panel the operator has two choices.
(a) Mouse (b) Key Board
In ESA11-IR the Operator can either use a MOUSE or a Key Board to carry out the Train movement operations of a station.
All VDU based operations except ‘emergency’ operations are possible only after the ‘operator’ inserts his ‘smart card’ (equivalent to SM’s KEY) into the ZPC. All operations of an ‘operator’ are automatically ‘logged’. However, The following ‘emergency’ operations on the VDU panel can be carried out at all times without the insertion of the ‘chip card’ or ‘smart card’.
Shifting of Signals to ‘stop’ aspect.
The process of route setting is exactly similar to domino based panel operation i.e click the ‘entry’ signal button & the ‘exit’ track button on the VDU panel. As soon as ‘command’ is registered on the VDU panel, the panel responds by:
◊ Change of colour of the particular function
◊ In predefined functions, ‘audible’ indication is also given
◊ If ‘safety’ information is relevant, it will be displayed on the text portion of VDU on the “page of risks”.
◊ In all cases the command is automatically “logged”
CONTROL LEVEL: (Interlocking Level)
In the Relay Logic, the safety of the Interlocking is achieved by the use of Relay Circuits. Here in Electronic Interlocking, the safety is achieved through software and reliability is achieved by using 2 out of 2 architecture with 100% hot standby.
This Level consists of a Special Rack, which houses the vital Computers, the maintainer terminal, the communication terminals etc. The typical equipment of such a special rack is shown below:
ESA11- IR ELECTRONIC INTERLOCKING SYSTEM
Front View Rear View
Fig.: The typical control Level TPC Cabinet Rack.
The ESA11-IR Control level or Electronic Interlocking level consists of technologic cabinet/rack in which are housed the following equipment:
1. Vital computer-TPC1 2. Vital computer-TPC2 3. Vital computer-TPC3 4. Vital computer-TPC4 5. Maintainer Computer- PCU 6. Maintainer Monitor
7. Communication HUBS
8. Associated Fuses, Power supply indicators etc.
All these are housed in a special 19” cabinet rack (TPC Cabinet).
The vital Computers TPC1, TPC2 are normally working computers functioning as 2 out of 2 Architecture i.e each computer or each channel works in total independence from the other & has a special comparator module which monitors the health of its own vital computer and during cross comparisons between TPC1 & TPC2 computers, if any discrepancies are found, the comparator module will generate a Fail Safe Reaction by ‘cutting off’ the power supply to its own vital computer. This reaction in turn will switch off the power supply to the second vital computer.
When TPC1 & TPC2 are in state of ‘active mode’, TPC3 & TPC4 take up the role of Hot Standby computers & vice versa.
Each Computer i.e TPC1 & TPC2 is having its own separate ‘General Software’ which is totally different from each other. Each ‘General Software’ is designed, & developed by different software teams. This assures that there will be no ‘Common Mode’ failures, which is an essential feature of CENELEC standard.
EXECUTIVE COMPUTERS: (INPUT/OUTPUT MODULES):
Executive level (PRV) serves as the interface between the Control (interlock) level on one side and the outdoor signalling gears on the other side.
After completion of an interlocking process step at the Control (interlock) level, i.e. after the dual processing of the data in each TPC & then after comparison between the TPC1 & TPC2 outputs, the resultant decision is then passed on to the respective executive computers PPa & PPb i.e. TPC1 to PRVa & TPC2 to PRVb, through serial links RS 485 or PENET. (PRVa is called Channel ‘a’ & PRVb is called Channel ‘b’ and both put together are called Executive Level PRV).
In ESA11-IR, the Executive Computers too use, dual CPU’s like at Control (interlock) Level, having its own intelligent diagnostic features, i.e. two independent channels are provided to receive the ‘data’ from their respective vital computers & then pass it on to the field equipment after a successful cross comparison activity.
The Capacity of each Executive Computer is: 1. Vital Outputs : 40
2. Vital Inputs : 80
3. Non- Vital outputs : 32
Please note that ESA11-IR treats all inputs as VITAL inputs.
The ESA11-IR has provision to connect 40 such Executive computers to one Interlocking Level i.e. at each installation the capacity of inputs outputs are:
1. Vital Outputs : 1600 2. Vital Inputs: : 3200 3. Non Vital Outputs : 1280
The Executive Level consists of the following modules: ◊ DCPU 1 & DCPU 2 Modules……..CPU Modules ◊ DOUT Module……….Vital Output Module
◊ PDOUT Module……….Associated module for Vital Output ◊ BVR Module………Vital Output Interface Module
◊ DINP Module………Vital Input Module
◊ PDINP Module……….Associated Module for Vital Input ◊ BN Module………Power Supply Module
◊ SO Module………Resetting Module
VHLC-E I OF M/S G E