IF TX SHOWS SLOW RESPONSE, WHILE A CLOSE LOOP AND WHEN
WE PUT THE CONTROLLER ON MANUAL THE PROBLEM RECTIFIED,
SO WE CAN SAY THE PROBLEM IS IN
Answer / carl_ellis
The problem is in the controller's PID tuning, which is
tuned to be too sluggish.
All of the loop's control components work properly:
- the transmitter reports the process variable
- the controller responds to an error (albeit too sluggishly)
- the control valve responds to the controller's output, as
evidenced by switching to manual mode
The PV response as reported by the transmitter depends on
the controller's appropriate response to error. If the
controller's response to error is sluggish, then the loop's
PV response will be sluggish.
Manual mode offers a means of overriding the PID's
calculated output value and driving the output to where it
needs to be.
This question qualifies as one of the best interview
questions I've read on this site. I'll be sure to use
this question when I interview candidates.
Carl Ellis
Measure First
| Is This Answer Correct ? | 2 Yes | 0 No |
What is the difference between Error and Offset.
Convert a pressure, level, flow, or temperature process variable value into the appropriate pneumatic or electrical value given different types of instruments.
6 Answers Jindal, MCL, Thermax,
Explain why use mmwc unit?
anybody having Qatar Petroleum questions for instrument Technician offshore ....please send me
what is weighfeeder
wt kind of business we can do by usig PLC?
What is the difference between a double acting and single acting positioner? what type of valves use single acting positioners?
1 Answers AquaTech, NamPower, Samson Resources,
whats the problem will arrise if we rotate the hosing screw of the differential pressure transmitter?
Why we are measuring 4-20ma? Why we are not taking 0-20ma? Plz answer this
What is the procedure of calibration of Load cell?
Can any one send me IOCL instrumentation question papers.. i dont know the pattern of the questions and what to prepare can any one help me on this .. my email id is anwarnishil@gmail.com
What is the SCAN time of a DCS/PLC? What is the typical value for scan time of DCS and PLC?
6 Answers Essar, Gasco, Siemens,
Civil Engineering (5086)
Mechanical Engineering (4453)
Electrical Engineering (16638)
Electronics Communications (3918)
Chemical Engineering (1095)
Aeronautical Engineering (239)
Bio Engineering (96)
Metallurgy (361)
Industrial Engineering (259)
Instrumentation (3014)
Automobile Engineering (332)
Mechatronics Engineering (97)
Marine Engineering (124)
Power Plant Engineering (172)
Textile Engineering (575)
Production Engineering (25)
Satellite Systems Engineering (106)
Engineering AllOther (1379)