Answer / loganatha subash . m

The main difference is, Many PLCs can be controlled through
one DCS, but DCS cannot be controlled by PLC. For the large
plant DCS is the best than PLC.

Answer / arjunsinh k rathod

Generally PLC are used if your used I/Os are limited, like
steel and paper industries where no. of DI,DO, AI and AO
are limited on the otherhand in petrochemical processess
where I/Os are used in thousands of numbers then DCS is
useful.

Answer / preethi

PLC is used for safety purposes in a plant. It ensures safe
shutdown during abnormal conditions.
DCS is mainly used for data acquisition, monitoring and
control.

Answer / sharah beel

PLC
Performance drop with increase in loop count.
Complicated and lengthy Ladder programming.
Large engineering efforts are required incase of expansion.

DCS
No change in performance with increase in loop count.
It has FBD’s programming.
Re engineering efforts reduced by 75% in case of expansion.

Answer / jonny jain

1)PLC is small syetem in which no. of signals like DI,DO,AI,AO
are less and DCS is wwide system where no. of signals are more.
2)Working speed of PLC is high than DCS because no. of signals are less in PLC.
3)PLC used in small plant and DCS used big plant.
4)More no. of PLC are controled by one DCS

Answer / sooraj unnithan

Number of pid blocks are more in dcs compared to plc

Answer / harish

plc is use only for a machine,
dcs use for a big plant ,its operate a big plant at a time

Im working in a shopping center, it is also hotel and office building, two towers exactly and someone is proposing a PLC control for the HVAC system, but Im thinking of a DDC control system. in this case what is the difference between PLC and DDC control?

1 Answers  

What is difference between ESD and PLC please Explain me clearly.

0 Answers  

how to calculate the temp. of RTD&Thermocouple when we got some mV r Ohms?if anybody has d chart pls mail the chatrs to me...

1 Answers  

how we can calibrate level transmiiter in field?

6 Answers  

for commissioning the DPT and Flow Transmitter , what kind of necessary activities we have to check and do? specially that orifice flange valve[ isolation valve}

1 Answers   L&T,

principle of automatic votage regulator

0 Answers   Bhel,

how we use the positioner feed back in split range control valves?

1 Answers   Tata Power,

How to calibrate level switch?

2 Answers   Power Plant, Sabic,

wich is coming the first HAZOP OR SIL

0 Answers  

How find CGPA? when marks are 515/850 & 2559/3350. Plz any one tell me.

1 Answers  

WHAT IS THE DIFFERENCE B/W PLC and DCS

10 Answers   Bhel,

Distributed control system

1 Answers   CCIE,