InfKaWu

Using two PWM function

11 posts in this topic

Hi,

I want to send impulses to the actuator by PWM (Pulse-Width Modulation). I have 2 functions which are using PWM with the same output, but in that fact, actuator doesnt move. If I have one function PWM, the actuator moves. Is there any connection with one PWM function which introduce the noise to second one? Is there any method to use two functions of PWM. Thanks in advance.

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What PLC are you using? Which outputs are you trying to activate?

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Hello,

 

24MR or MT?

R is relay version

T is transistor one

only T is able to PWM

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It ran in my mind that you can only have 1 instance of a PWM instruction.

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On 7.11.2018 at 0:34 PM, sczot said:

Hello,

 

24MR or MT?

R is relay version

T is transistor one

only T is able to PWM

I have version 24MT

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On 7.11.2018 at 6:21 PM, kaare_t said:

Not possible with your unit, see manual:

pwm_fx3g.PNG

Sorry, I have outputs Y0 and Y1.

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When I have this functions, which are shown on the fig below, the actuator moves.

PWM_1.jpg

PWM_2.png

But if I add another PWM function with the same output, the actuator doesnt move.

PWM_3.png

Lights on the controller is showing that controller uses outputs. I tried to block one function of the PWM by using memory bit but it  didnt work.

 

PS these two functions for the output Y1 dont work simultaneously. I want to move the actuator automatic and manual.

Edited by InfKaWu
Bad sequence of the images

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Did you try, as a test, to set static values in s1/s2 on both PWM? Just as a test to make sure nothing is wrong with min/max limits regarding your variable inputs...

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Check m8340 busy/ready flag.

If it's still on for some reason you can't execute another pulse output instruction for y0

There's no limit of PWM instructions as long as you do not execute more than one at a time for the same pulse output.

If you use indirect variable inputs with data registers for both PW and interval, u need only one instruction and just change variables...

When there's no PWM execution, you can use y0 as regular output

What type of actuators do you control?

Maybe positioning instructions like PLSV and DRVI are more suitable for your application?!

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