Incremental Rotary Encoder reading stability issue ...

Hi, Everyone

I am interfacing rotary encoder(incremental encoder) with PLC. This encoder using for speed measurement (RPM). The encoder is giving pulses which reading is not stabilised for every rotation of same speed. it is fluctuating 0 to 5 pulses which results to variable readings.
For this problem, I have done following things..
1. Encoder wire shield is connected to earthing.
2. Separate encoder wire routing.
3. Averaged the encoder reading pulses in PLC program
4. Find max value program of encoder pulses in PLC.

But, still it has variable reading. Kindly help me out.

PLC- Siemens ST20-smart
Encoder : Delta ES3- 360PPR

Regards
Nilesh

What is your encoder on?
How is it coupled to the load?
99% of the time, if the encoder is fluctuating, so is your speed.

rdrast said:

What is your encoder on?
How is it coupled to the load?
99% of the time, if the encoder is fluctuating, so is your speed.

Click to expand...

Encoder is connected to conveyor which carried by a oriental make three phase induction motor around 150-220 watt(3-Phase 240 VAC).

What inputs are you using to connect to the encoder?

How is the coupling done?

8/10 times, the coupling is loose or broken.

1/10 times, the coupling is not flexible and is at an angle causing a wobble that is visible in the encoder readings.

cardosocea said:

How is the coupling done?

8/10 times, the coupling is loose or broken.

1/10 times, the coupling is not flexible and is at an angle causing a wobble that is visible in the encoder readings.

Click to expand...

I asked same thing with mechanical person and checked. Remaining flexibility only we can assume that it is OK.

I want to find this solution through software logic...

Define the actual problem. You aren't going to get servo like speed control from a conveyor. What are your real (and not wishful) requirements ?

The speed WILL actually change as loading changes, that is normal.