Answer / inbu raja e k

cascade control strategy is the one in which you have 2
control loops, a primary loop and a secondary loop. The
output of the secondary controller will the reference or
set point to the primary controller.
Cascade control is most advantageous on applications where
the secondary closed loop can include the major disturbance
and second order lag and the major lag is included in only
the primary loop. The secondary loop should be established
in an area where the major disturbance occurs. It is also
important that the secondary variable respond to the
disturbance. If the slave loop is controlling flow and the
disturbance is in the heat content of the fluid, obviously
the flow controller will not correct for this disturbance.
In distillation column it is used as a composition control
where the feed flow is the primary control and condense
flow out is the secondary loop

Answer / amit123.inc

Dear Inbu Raja E K-Actually the output of the primary controller is used as the reference or setpoint for the secondary controller.

can we use flow transmitter instead of level transmitter?

7 Answers  

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SIR MAY I KNOW IF RADAR TYPE LEVEL TRANSMITTER SHOWING IN THE FIELD 0 % LEVEL AND IN DCS SHOWING 100% THEN WHAT IS THE CAUSE I CLEAN THE CHAMBER & TAKEN ONLINE BUT ONLY ONCE ITS BECOME ZERO IN DCS BUT AGAIN 100% SHOWING IN DCS,THEN I REMOVE THE POWER SUPLLY AND CONNECT IT AGAIN .IS IT OK BUT STILL IN THE DCS ITS 100% AND ON THE DISPLAY ITS INITILAZIATION PLEASE HELP ME READRING THIS?

4 Answers  

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difference between DCS @ SCADA system? and how can use in field

5 Answers   Marafiq,

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Can I put my meter across an RTD to check it safely witout tripping the equipment when it is connected to an monitoring device eg.RTD module or IQ 1000

1 Answers  

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How to do manual mapping in radar type level transmitter?

2 Answers  

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what are the documentation and instrument identification system used to identify the correct device to be calibrated? name atleast three.

1 Answers  

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HOW TO DO PERFECT CALIBRATION OF DIFFERENTIAL PRESSURE TRANSMITTER FOR CLOSE VESSEL TANK LEVEL PURPOSE ???? AND HOW TO MAKE ZERO PRESSURE ?? Rosemount 2051 Pressure Transmitter with HART® Revision 5 and 7 Selectable Protocol BIENG USED !! HOW TO CALIBRATE FIELD SIDE DPT WITH THE HELP OF SPAN & ZERO PUSH BUTTONS ??

1 Answers   Bhel,

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what is the difference between Digital output DO signals /Commands for start/stop and Solenoid valves ??

1 Answers  

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Why 1-5 vdc a standard?

1 Answers   Process Control Technologies,

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How servomotor controls throttle valve of TURBINE?

0 Answers  

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What is the purpose of valve positioner. Explain 4 uses.

2 Answers   SRACO,

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whats the diff b/w zero pressure and obsolute pressure

4 Answers  

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