Areeb

High Speed Input

7 posts in this topic

Hi Everyone

 I want some suggestion actually I have a machine which place left and right tape
in the product at same time. The Code picture is given below. It works fine in medium speed
but the problem is that when I increase the machine above 280 RPM so it will mal operate 
due to which it gives the signal and consider the product having no tape on it and reject it.

So my question is there is any other logic which I can use here instead of below so that
it will not reject the right product and it will sense in higher speed as well.


I don`t understand this why this problem occurring in higher speed.if there is any other logic which sense the tape individually please let me know.


please provide me any solution I will be very thankful to u.

 

Left Tape Sensor 50C

Right Tape Sensor 50D

Thanks 

Untitled.png

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There are two thing to consider.

Looks like this is part of your regular Scan program so it will only run every ..... ms
But the second is probably the problem which is the amount of time your sensor is on.
At higher speeds it's only on for less time. Your input would have a minimum time before it is seen as true (probably 10ms)

Which PLC are you using ?

So to change this you will have to change the Input Response time time of your Input card and maybe put this part of the program into an interrupt program. 

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Yes u r right it is a part of regular scan program.

I have checked the response time it is already set to a lower value that is 0.1ms.

I am using Mitsubishi Q series PLC (Q03UDECPU).

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In that case maybe your scan is just to long for operation.
you should put this program into an interrupt program.

Instead of using X51 for instance use DX51. (This way the current status is checked for the input and not the status at the start of the scan).

Have you used interrupts before on a system Q?
 

 

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The program file which I have of this machine consist of some interrupt program  but I don`t create it my own interrupt program before in this PLC.

I have Modify the changes u said above kindly check in below pic is it okay will I try this one ?

Untitled.png

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OK this is correct for checking the current status of the inputs.

However your SCAN time will probably still be an issue.
You should take this part of the program and add it to the time interrupt program.  (i28 i19 etc one which is fast enough)

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