Answer / Vishwasana

1. Modbus cable is a common industrial communication protocol used in automation control systems. The most common type of cable used with Modbus is RS-485, which is a two-wire twisted pair cable.
2. For the interface of DCS (Distributed Control System), ESD (Emergency Shutdown System), and third-party cabinets, various communication protocols can be used such as Modbus, Profibus, EtherNet/IP, and Foundation Fieldbus. The choice of protocol depends on factors like system complexity, cost, and compatibility with other devices.
3. Serial communication is a point-to-point communication method that transfers data between devices over a serial interface. Data is sent one bit at a time in a serial format (as opposed to parallel format). Peer-to-peer communication refers to a type of network topology where all devices on the network can communicate directly with each other without the need for a central server or hub.

In RTU Panel we are having several Analogue & Digital Inputs /Outputs. We are recently facing some problems over Analog inputs , which are not updating properly (But Digital Input are updating normally) Can any one tell me from where the problem is creating , we have checked PLC CPU card, Analog Input card & we reconfigured ,But still the issue is there. Issue : 1. Sometimes Analog values are updating & sometimes not. 2. Analog values are not updating normally , showing some wrong Values 3. Total dead (0 value) Analog values are Level & flow measurement from the field instruments. (But in field the instruments are working normally & Displaying the values normally in local display unit) This problem we are facing in our Water Plant. If any one experienced this same problem or having any ideas related to our issue PLS send your valuable Answers/Replies...

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Hi all, I am Mohamed from Algeria, I'm a senior Technician qualified in instrumentation. I work in an international petroleum and gas company (SONATRACH: Separation of associated gas from crude oil. Production of condensate, LPG and re-injection of dry gas) within the regulation & Control instrumentation department.I am interested for working in Qatar Petrochemical Company (QAPCO) in Qatar.Now,I am seeking a position, which is an opportunity for me to put my experience to good use and actually participate in running on this company. So, Can anyone help how to contact this company? Thanks Mohamed, mahad8331@gmail.com

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HELLO FRENDS ,, I M IN THE MIDST OF TROUBLE .. JUST LITTLE HELP ME... SUPPOSE ,, I HAVE A CLOSE VESSELE TANK ( HEXANE MEDIA ) ,, I M USING ROSEMOUNT 2051 DPT FOR LEVEL APPLICATION .. ITS CALIBRATE RANGE IS.. . 0 TO 950 MMH20 ..I DID CALIBRATED DPT WITHOUT REMOVING IMPULSE LINE OF HIGH AND LOW TAPPING.. & WITHOUT DISTURB 3 WAY MANIFOLD..!!! BUT ,,, DURING CALIBRATION I SELECT RANGE BY HART LRV IS 900 MMH20 & URV IS 1300 MMH20 ,, BUT ,TANK LEVEL SOMETIMES 100 % AT 1100 MMH20 , SOMETIMES 1300 MMH20 ..IN THIS CONDITION .. WHOLE LOOP FAILED ,, MAIN THING IS THAT ,, HOW TO CUSTOME RANGE SELECT ?? AND IF I USED RANGE OVER THE ORIGINAL CALIBRATE RANGE ,,,THEN WHAT ERROR WILL BE COME ??? HOW TO ZERO CALIBRATION OF DPT... HOW TO ZERO TRIM BY MANIFOLD ?? AND FOR TANK LEVEL PURPOSE ... WHICH UNIT I CAN USE ??? IS THERE ANY CALCULATION OR CALIBRATION .. IF YEH .. THEN PLZ JUST GIVE ME CALIBRATION STEPS FOR DPT.. THANKS YOURSSSSSSS

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