The Central Control Unit (CCU) is the "nerve center" of the PROPAM system. From CCU, all the stations of the system are logically controlled; various system information and data are logged, maintained and communication links are established and disconnected as per user requests. The complete system consist of CCU, DESKTOP STATION FOR CONTROL ROOMS WALL MOUNTING STATIONS FOR WEATHER PROOF STATIONS FOR OUTDOOR PURPOSE (WITH and WITHOUT CANOPIES), POWER CUM JUNCTION BOX, SPEAKERS and Interconnecting Cables.
The CCU design is state-of-art of hardware. The total design provides utmost ease in assembly and servicing. All the cards of the various sub racks are plug-in type. Each sub rack carries its individual power supply (SMPS) module. Every sub rack carries a motherboard PCB - eliminating the need for hand soldered backplane wiring. The connections between the sub racks and the field cable terminations are standard and not dependent on system configuration or communication chart. Further, these connections are routed via flat cables with lockable connectors. All these features provide an extremely modular and efficient means for assembly and maintenance of CCU.
The CCU is designed for an attendance free operation. A system program resident in the memory of the CPU which continuously scans for receipt of service request from stations on a sequentially polling basis. On receipt of such a request, it performs appropriate actions for that station and resumes scanning once again. The actions are in accordance with a communication chart stored in EPROM. The communication chart is prepared as per as user requirements. The CPU controls the overall operation of the system by controlling the operation of DLI cards and the DIAGNOSTIC MODULE. The DATA LINE INTERFACE cards act as a link between the stations and the system whenever the station(s) requests for system's service. The actual data communication between the CCU and the stations are takes place through DLI CARD. Each DLI card can support maximum 8 data line terminations. The total set of DLI cards essentially function as 1 to 80 line multiplexer.
The main function of RELAY SUB RACK to establish audio communication link between a set of communication stations under the control of the CPU. Each triangle relay sub rack is capable of interconnecting a maximum of 32 incoming audio channels with 32 outgoing audio channels while each rectangle relay sub rack is capable of interconnecting a maximum of 64 incoming audio channels with 8 outgoing audio channels. By appropriately interconnecting multiple numbers of such relay sub racks to each other, a non-blocking (i.e. full availability) audio communication between a given set of stations can be realized.
SYSTEM CAPABILITIES/EXPANSION :
The total PROPAM System can be expanded to a maximum limit of 80 Communication stations. The total configuration fully depends on the USER'S COMMUNICATION CHART. The system has following capabilities:
MAXIMUM NUMBER OF DIRECT CALL FOR A STATION : 6
MAXIMUM NUMBER OF GROUPS IN A SYSTEM : 10
MAXIMUM NUMBER OF STATIONS IN A GROUP : 20
CABLE LENGTH SPECIFICATION :
The System shows satisfactory performance over a cable length of 6.00 KM from CCU to individual station in an industrial environment by using a recommended cable. 2 to 5 Pair/0.5mm cable is recommended for interconnecting the CPU & STATIONS, depend upon the facility selected by the user.
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