Counting Encoder pulses over time

[MrT]

Hi All, 

I need some advice please:

I have the following setup:

NX1P2-9B24DT1 (PLC)

NX-PF0730 (24v Card)

NB3Q-TW01B (HMI)

3G3MX2-AB015-E CHN (Motor Drive 1.5 KW)

3G3AX-MX2-ECT (Ethercat module for Motor Drive)

NX-EC0122 (Encoder Card)

E6C2-CWZ5B 360P/R 2M OMS (Encoder)

 

I need to count the pulses from the encoder over a set period of time. I only require one chanel, z for instance. 360 Pulses per rotation is more than sufficient resolution. 

I need to count these pulses of a set time period to determine the speed a media is moving through the encoder wheel and adjust the speed of the motor accordingly. 

I know how to alter the motor frequency and thus control rpm, I can calculate the speed by determining through calculation,  the distance traveled relative to wheel diameter. 

 

My only unknown is how to read a number of pulses on a channel over a set period of time...200ms (0.2 sec) as an example to have as an input for my calculation.

I am also not sure of the correct setting for this application on the sysmac setup of the Encoder card.

 

I would be grateful for some guidance. 

 

Many Thanks, 

[Crossbow]

Check the manual on the card settings, there is a pulse rate measurement function built right into that card.  In the settings you can set the Time Window in milliseconds.  The manual should explain how this is set and how to program it.