Answer / surendra singh tanwar

I/O are required to convert the process value or status in
to a formet which can be communicated to the controller and
v/v controller to processe

Answer / delta_v

Remember that from field instruments the signal sent are only process data (example temperature, pressure); these data can't be read by the controller, hence it will become useless.
That is why IO cards are used to convert these to a readable signal which is 4-20mA.




"You cannot measure, what you cannot control"

Answer / makinde motunrayo

why we don't use I/O directly with controller.
The controller here is PLC, I/O is not use directly because of space the back-plane will occupy . i.e Organisation of instruments from field to the controller.

i have steam drum height 1000mm. and i want to placed the transmitter below the tap.how i calculate.

0 Answers   OEG,

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A temperature sensor (RTD) connected via a temperature transmitter is adjusted to give an output of 4ma at 60 deg and 20 ma at 600 deg. This output (4-20ma) from the transmitter is connected to an IGBT-inverter to control a high speed (-12,000 to +12,000 RPM) DC motor. And in the inverter it is programmed as, for 4ma the motor speed will be -3,000 RPM and for 20ma the motor speed will be +10,000 RPM. The question is : If the motor speed is +5,500 (RPM), what will be the temperature? (-sign indicates that the motion is in reverse direction).

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control modes

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what is type of protocol used in instrument field to marshalling cabinet cabel. what is the differenance between bus cabel and instrument cabel?

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Hi,can anyone help me out with PhD programs related to Instrumentation field?I have a degree in electronic Instrumentation?

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An atmospheric storage tank has a diameter of 20 m and a height of 8m.It is half-full of liquid with the remainder of the space containing air normally at atmospheric pressure. If the connection to atmosphere is accidentally closed off and 10 cubic m of liquid removed, what happens to the internal pressure of the tank? What are the possible consequences for the tank?

1 Answers  

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What should be the ideal tapping location for pressure differential transmitter for liquid service. If the tapping taken from the top of the pipe then PDIT will work properly or not. If PDIT do not work properly then what minimum corrective action should be taken in order to solve wrong tapping locations.

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Difference b/w SCADA & DCS

8 Answers   Siemens,

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