Omron rotary Encoder- GX series

[noorloai 0]

Hi,

In my application, I have OMRON rotary increment encoder (E6B2-CWZ6C) connected to Axis encoder GX-EC0211 using EtherCAT technology to the master NJ501-1330. See attached picture

The increment encoder used to control the position.

I want to use the existing equipment to get the number of motor rotation so I can calculate the total work travel in mm

Total work travel = work travel distance per motor rotation * No. of motor rotation

Please advise if that possible without affecting the current application? And if so, how can I get this value?

Appreciate your consideration and support in advance.

Noor

[Crossbow 295]

You only get one set of calibration data for an axis.  Based on your pictures, the axis is already set to operate in mm.  So what is your question?

The axis name is MC_LMeasure, and there is a complete system variable full of axis information under that name.  The current position would be MC_LMeasure.Act.Pos.  Just like working with any encoder or servo axis.

[noorloai 0]

I have a spool loaded with material and I want to monitor how much we used from it and how much left over in the running time. And I am wondering if it’s possible to use the rotary increment encoder in this case?

I know t

he rotary encoder is a position sensor used to determine the angular position over rotating shaft which used to monitor the spool position in my case. but I am thinking if there is a way that I can get the number of motor rotating?

if I can get the number of rotating and multiply it by work travel in mm will give me how much I used from the material.

I am thinking out load here and looking for your feedback/ advice based on your experience.

Thanks,

[Crossbow 295]

You don't have to do any of that.  Your axis position will tell you how far it has moved in mm based on the screens you shared before.  It's already done, why are you trying to repeat it?

[noorloai 0]

I need to display on the HMI the total I have used from the starting till the ending of the process.

If I start with roll 500 m length, I want to know how much I used at the end of the process? will that possible?

[Crossbow 295]

I already provided you with the information.  Your axis is configured in mm, so the actual current position shows how much has moved.

 

[noorloai 0]

Hi Crossbow,

I have an issue in retaining the left value when the power cycle, it goes back to zero. Is there any way that can retain the value?

left size = total size- used size in mm where:

• The used length is = MC_Axisname.ACT.POST

• Total size: is an input from the HMI and its retained from the global variable table

• Left: is output display to the HMI which is also retained variable from the Global variable table

Thanks

[Crossbow 295]

If your variables are set retained, you should not lose anything.

[noorloai 0]

all variables are retained except MC_Axisname.ACT.POST, And the equation is based on this values therefore when the power cycle every thing goes to zero except the total number from the HMI.

is there anyway to get this MC_Axisname.ACT.POST value retained?

thanks

Edited 14 Oct 2016 by noorloai

[Michael Walsh 268]

The only way that it is retained is if you have an Absolute encoder.  If you turn power off and then move the encoder by hand, you do not want the position retained for an incremental encoder. 

If for some reason, you need to retain the position, use a MOVE instruction to move the position into a retained variable.  Then upon power up set the position of the encoder to the saved position.  This would be a strange thing to do with an incremental encoder though (see my first comment, one line above).

[noorloai 0]

Hi all,

Please, I want to understand how did they calculate the Command pulse count per motor rotation and the work travel distance per motor rotation in the software configuration.

The module I have is  E6B2-CWZ6C 360 P/R - 2M .

based on the equation that I have in the software, I would like to check the unit is configured right in my system.

Thanks a lot for your support in advance.

[Crossbow 295]

My guess would be they chose 1440 pulses per rev because maybe there is a 1:4 gear box in the system?  Your encoder is 360ppr, so that value is 4x the encoder.

As for distance of travel, that is dependent on the mechanical system.  You need to measure or calculate it based on how far the load moves when the motor turns one complete revolution.

[noorloai 0]

Thanks Crossbow for your prompt response.

[Michael Walsh 268]

Looking back at this post, it sounds as if the encoder is tied to the shaft of the spool.  Therefore, you cannot really work in mm directly as the spool diameter will either be getting larger or smaller each time that the encoder turns.  Usually in this type of configuration, you would have to know the starting diameter somehow and then each 360 degrees that come off the roll, the diameter needs to be adjusted by the thickness of the material x2.  So, I would recommend setting your units up in either degrees or rotations.