What is DCS and PLC scanning time?
Answers were Sorted based on User's Feedback
Answer / abhishek
Main difference between DCS and PLC is about the scanning
time. PLC's have a fixed scanning time whereas DCS
execuation order(scanning) can be varied with certain
minimum limit. Generally a PLC can have a scan rate of as
low as 5msec(fixed) to some where around 20msec(fixed). As
DCS handles larger number of inputs/outputs its scanning
rate is 50msec and this value needs to be defined (can be
kept more than 50msec) while writing a program. But latest
DCS can have scanning rate of 20msec.
Is This Answer Correct ? | 7 Yes | 2 No |
Answer / vijay
Scan time is time required for checking i/p,to executive
program and give out put.generally 5msecfor plc
Is This Answer Correct ? | 9 Yes | 8 No |
Answer / abu maryam
scanning time:
In general: scanning time: it is the time taken to read all inputs then execute the program and apply on outputs.
In PLC: it is only 1 processor check the previous procedures so its scan time depend on the quantity of data and program.
In DCS: There are several processors each processor has its inputs and outputs and its private program so each processor in DCS has its private scan time applied on each loop.
Is This Answer Correct ? | 0 Yes | 0 No |
Answer / srikrishnan
SCANNING TIME OF PLC DEPENDS ON THE NUMBER OF RUNGS, JUMP
COMMANDS, SUB ROUTINES, AND INTERFACING DRIVER
CONFIGURATION. THERE IS NO FIXED SCAN TIME FOR PLC.
Is This Answer Correct ? | 2 Yes | 3 No |
please tell me five types of fault of control valve and positioners?please
i want to measure temp of hot sand(welding flux) in closed chamber(around 150 deg C).Which is better thermocouple or thermometer?
in mass flow meter what is drive friquancy ?
which are types of orifice tap ?
Why the Proximitor supply should be Negative voltage? Why should not we give Positive voltage to the Transducer?
Q- Ordinary Water Tap is which kind of controller ? P , PI or PID i chose the option of ON - OFF type controller but ambiguity is that for different positioning of tap we get different flow
detail of mass flow meter pricipal
what are the steps I have to deal with?
-200mmwc to 500mmwc range transmitter have there 4mA is -200 and 20mA is 500.what is the range in 12mA?
How you calibrate absolute pressure with the calibration range of 0 to 1000 0C Absolute. Please explain the procedure for calibration.
steam drum level transmitter calibration procedure? with example?
what is HVAC?