Exact time is essential for the operation of metros as well as for railways. The time is traditionally displayed on platforms, in waiting rooms, shopping areas and in offices using analog and digital clocks. In addition, a precise time reference is also used for the synchronization of subsystems such as access control, surveillance cameras, loudspeaker systems, etc. In addition, analog clocks in particular are important carriers of the corporate identity of a metro or train by means of logos, shapes and colors in the respective corporate design.
All of these requirements also apply to one of the largest metro systems worldwide, the Delhi Metro. This system, which is managed by the Delhi Metro Rail Corporation (DMRC), currently comprises a network of over 180 kilometers in length and 138 stations. Mobatime has been involved in the implementation of this impressive metro network as a provider and service provider of clock systems and time systems for several years. In phase I, deliveries were made by Bürk Mobatime through a large, German system integrator. Phase II was managed by a French company, which was supplied with Mobatime products through its Swiss headquarters. In this constellation, extensions to phase II & phase III has implemented and planning work for the upcoming phase IV is being advanced. In parallel with the hardware deliveries, Mobatime India Pvt Ltd, which belongs to the Moser-Baer Group, based in New Delhi provided project services such as commissioning, training and after-sales support in all phases of the project.
Holistic solutions, consisting of technologies and products as well as services, shape the strategy of the Moser-Baer Group. Time systems and clock systems have been developed, produced and sold worldwide for 82 years. Today, this is done with ten branches in six countries - Switzerland, Germany, the Czech Republic, Russia, India and China - and with more than 150 sales partners in another 120 countries.
In the first expansion phase of the Dehli Metro, the time distribution between the master clocks was made according to the state of the art at the time via serial connections. The fine distribution at the stations and the synchronization of the clocks was carried out using MOBALine; a time protocol developed by Mobatime and used in thousands of systems. It is transmitted over a simple two-wire line up to 1600 meters and supplies self-setting clocks with time and date information through automatic time transfer. In a next expansion step, time distribution at master clock level was implemented at Delhi Metro using the Network Time Protocol (NTP). At the same time, another Master Time Center was installed at the central location in Barakhamba Road in order to increase availability. NTP is transmitted to the substations along the metro lines via the Fiber Optics Transmission System (FOTS). Since the slave clocks on the substations should continue to be synchronized with MOBALine, it was necessary to have network-compatible master clocks with MOBALine outputs to the slave clocks. Redundancy and high availability were ensured here with monitoring and switching devices.
Further developments have also been achieved in the analog and digital slave clocks. The purchase, expansion, operation and maintenance of clock systems and time systems for metros and trains in large cities such as Delhi with dozens of stations and a network of routes branched out over hundreds of kilometers are subject to specific requirements.
Investments made should be retained in the event of extensions and should not have to be replaced. This is done through an open system concept in order to be able to use existing and future technologies - serial, MOBALine, NTP - in connection. By fully integrating the relevant time sources, an identical time should be made available in the entire route network.
Mobatime at DMRC solves these requirements with modularity and compatibility. At the central locations, the Master Time Centers ensure that different time signals - serial telegram and NTP - are fed into the network and that multiple technology generations can be operated in a compatible and simultaneous manner. This is done using a modular concept. The various time signals required are provided by specific, intelligent modules in the same master time centers. This also ensures that by adding additional modules there is enough capacity for master and slave clocks on the substations. Compatibility is also found in the master clocks on the substations. The master clocks of the second expansion step are network-compatible.
Coming to the Indian metro projects, MOBATIME India has been doing more than 70% projects in India with some big references like DELHI METRO, JAIPUR METRO, KOCHI METRO, CHENNAI METRO Ph-1 & Ph-1 extension, AIRPORT METRO EXPRESS LINE NEW DELHI, RAPID METRO GURUGRAM, NAGPUR METRO, GUJRAT METRO, PUNE METRO, MUMBAI METRO LINE-3, MUMBAI METRO LINE-2/7 and many others.