de HOrder code Article No LP A Z Auxi B4DV-25-C Bevel-helical speed reducer B4

Flender/Flender Gear Units/Bevel-helical speed reducer B4

unication system shall be digital communication bus tha provides high speed data transfer rapidly and reliably between the opera tor consoles, process / devices, process controller and devices connected it. The data communication system shall include redundant system bus with hot back up and other applicable bus system like cubicle bus, local bus, / bus etc. Communication system shall be dual redundant, consisting of two separate communication buses and two separa te communication system inter faces for each device. In case of system having traffic directors, redund ant traffic directors shall also be provided. Communication speed on the comm unication bus shall be sufficien to update the operator console data base once in every second. The overal system performance shall not be degraded whether communication system is 1% loaded of 1% loaded. Degrada tion of communication bus is defi ned as change in the system performance from the specified one while oading the communication system from 1 through 1%. In case of main bus failure or any communication device failure , the transfer to the backup device or bus shall be automatic without interruptin the system operation and without any operato rs intervention. Information about the failed device / bus shall be displa yed on the operator console. It shall be possible to switch over the communication from main redundant bus manually without disturbing the system operation. In general the transmitting messa ge shall identify the receiving device. The transmitting device shall receive reply from the receiving de vice on the 1 of 1 INDRADHANUSH GAS GRID LIMITED TECHNICAL SPECIFICATION FOR NATURAL GAS COMPRESSOR STATION FOR NORTH EAST GAS GRID PIPELINE PROJECT TS NO.: MEC//2UU/0/2/0 Control & Instru mentation (&) Chapter-0.0 2, MECON Limited, All Right Reserved Page 1 of 1 receipt of correct message, lack of response shall be considere