Error percentage

Hello BINU K,
That depends on a number of factors. Could you please tell me more about your application?
Important things to know are:

1. The full MSP part number (such as MSP430F5529 or MSP432P401R)
2. What peripherals are you using on the MCU for measurement? (Such as the ADC, SD, Timer A, etc)
3. Any other information, such as code snippets, measurement method, etc, is always helpful.

With 1 and 2, it's really hard to get a good number for expected error.

Best regards,
Cameron

Hai Cameron LaFollette,
Thank you for your fast replay.
MCU iam using is msp430FR5969, with external interrupt for reading position sensor count, within a particular RTC timing.
But my question is, suppose my rpm setpoint is 2500 and measured rpm is 2650 within 500 milliseconds.
Is it permissible?

BINU K,
If I'm understanding correctly, you're using the time differences from RTC to measure position and extrapolate RPM?
In this circumstance, yes it would be error prone.

What kind of position sensor are you using?

Best regards,
Cameron

Hai,
Yes you are correct, I am using the time interval for manipulation of these rpm.
Here I am using the hall effect position sensor

You might consider using TimerA for this, it will have a greater accuracy for what you are trying to do. The easiest way would be to reset TimerA each time you read it in the interrupt.

Let me know how that works, or please click the green "Verify Answer" button.

Best regards,
Cameron

BINU,
Can you give me a status update on this? Do you have any further questions, or did we help you solve it?

Best regards,
Cameron

Hai,

        Sorry in that time Iam tuning Engine.

Here I found one more problem is that , even though  the throttle position of  Engine fixed manually ,rpm varying a little.

My friend , expertised in engine mechanics said that, carburetor used petrol engine shows this problems.

So I think , the problem is coming from both engine side and program side. The  more inconsistency is from engine side.