Increment Encoder to PLC with High Speed Input

I had an increment encoder (A+ A- B+ B- and Z+ Z-), for checking the encoder I use a PLC with High speed input counter (For example FP0-C16CT).

To calculate the encoder, I connect the encoder A and B to the high speed counter.

At plc programing, the step I did as following:
1) looking the signal for Z, which means when Z is detected the counter reset.
2) Looking the A coming first or B coming first to detect the CW or CCW.
3) Start counting and Sum up of A and B to get the resolution before detect the Z signal.

Did my concept right the encoder testing?

use oscilloscope

Use oscilloscope is not a problem but the problem is I dont have oscilloscope

1.) go to TV repair shop they have oscilloscope pay them few RM.

2.) check www picotech com/picoscope-oscilloscope-software.html


you need good quality waveform

Thanks.

For the picoscope oscilloscope, how pc read the data?
Does it require additional input card?

yes,

contact local rep,you will get more infomation.

www picotech com/distrib/my/



my.element14.com/pico-technology/picoscope-2204/oscilloscope-2-ch-10mhz-100msps/dp/1471476

my.rs-online.com/web/c/?sra=oss&r=t&searchTerm=picoscope&x=34&y=12

Just a guess. Are you sure you have setup the PLC for a high speed incremental encoder input? Your description looks like you are trying to manually decode the A/B/Z inputs, whereas a 'high speed' input does that for you automatically and all you see from the software side is a counter. Otherwise you are trying to decode the high speed inputs at scan rates - and there is nothing high speed about that.

So I'd suggest you read the manual closely and find the section about configuring and wiring for high speed inputs. I would expect there is something you have to do to identify specific inputs to be configured for an incremental high speed encoder - and you can only wire to those inputs. Sorry I can't speak directly about your Panasonic PLC - not experienced with it so I am speaking in generalities. Also, be sure your high speed input frequency does not exceed the frequency response of your high speed inputs (2kHz on this PLC?). If you have a 1000ppr encoder running at 1800 RPM, that is 30Khz - so you would need at least a 60 Khz high speed input in that case (sample at least twice the input device frequency - Nyquist). Plus many PLCs can't handle the differential encoder inputs, so you have to convert them to single ended and be careful about your wire lengths and terminations.

Just use a proper tool to test your encoders. Hint: A PLC ain't it.

https://www.dynapar.com/Products_and_Solutions/RIM_M100_Encoder_Tester/