PWM physical output

[Joe Tauser]

 

3 hours ago, CobryWZL said:

The flow counters send a digital signal and every count is a 0

OK, now you've confused the hell out of me with your logic.  Do you mean that the input goes low (NPN type) on a pulse?

This is why I always ask people to attach their program to their post.  We know nothing about MI 63 other than what you've shown us.

Let's talk it through....

Rising edge of I0 (count pulse)  ->  If MB 17 is off  reset the count (?) to 0 -> Turn on MB 17.  

MB17 will be on for only one scan.  So MB 17 NC will always be TRUE and your count will always reset.

Am I missing something here?

 

Joe T.

[Ausman]

I think the issue is that you are trying to do two things but actually combining them incorrectly into one rung.

To me it looks like you want to zero the count on pump startup.

So you have your initial rising edge (whatever that is...a button push?) that gets everything going.

This push resets the count to 0, and also permanently enables the rising edge of I0 to do an Increment of an MI (the actual count) until the process stops.

But as Joe says.....what in the world does MI63 do?  Perhaps you have given it an odd name that implies something to do with time, when in fact it should simply be "Water Count" and undergo the increment in another rung.

Hmmmmm??

cheers, Aus

[kratmel]

I wonder what the author aims to get?
Need to ensure proportion in a continuous mixing process?
Need to measure two doses of the component and stop?
Is it possible that the ultimate goal is to get these two goals at the same time?
 What accuracy of maintaining proportions is required?
Do both components fall into the same line or flow freely separately?
 

This is a small part of the questions that the author should answer for himself.
And I think then it will become clear what should be written in the PLC program.

From the above data on flow meters, I did not see how many pulses they emit per unit.
It is difficult for me to advise how to count impulses without knowing the purpose for which the author wants to do it.

[CobryWZL]

16 hours ago, Joe Tauser said:

 

OK, now you've confused the hell out of me with your logic.  Do you mean that the input goes low (NPN type) on a pulse?

Sry for confusing you, but thats what I wanted to say. If I read the datasheet of the flow sensors right, the sensors sends a square wave signal and for every count, the signal is low (0). 
We want to read this squre wave signal with our SAMBA and implement a counter in a net, that tracks the counts of the sensor ( by counting the times when the signal is low).

We are not sure  to which physical input we should connect the signal cable of each sensors, how we should configure the HW settings ( digital input, highspeed input or highspeed counter) and what the net with the counter needs to look like.
I think you can ignore the net i posted, because its just totaly wrong...

7 hours ago, kratmel said:

From the above data on flow meters, I did not see how many pulses they emit per unit.

 

It is difficult for me to advise how to count impulses without knowing the purpose for which the author wants to do it.

One flow sensor (for oil) does 462 impulses per litre and the other (for water) does 65 impulses per litre. Its on page 4 of the data.

[kratmel]

Hi, now you has two different sensor with npn output. You must setup NPN input type on SAMBA.

1 -st sensor

min rate 0.06L/min х 462 imp/L = 27imp/min,   min imp rate 0.45Hz

max rate 16L/min х 462 imp/L = 7392imp/min,   max imp rate 123Hz

 

Normal input speed (Hz)   typical 10ms response  = 1/ 0.01sec = 100Hz

Then you must use HSC for this sensor.

 

2 -nd sensor

min rate 3L/min х 65 imp/L = 195 imp/min,   min imp rate 3.25Hz

max rate 30L/min х 65 imp/L = 1950 imp/min,   max imp rate 32.5Hz

 

Then you can use one of them - normal or  HSC input  for this sensor.

 

Then you can use V570_Frequency-precise meter.vlp  code and HSC configuration in HW configuration of your project from help

for  test flow meter and see what happend when you try to SET differnt PWM for motor.

If you see Hz in range calculated abowe for both sensor - maybe your can use part of this code in your application. 

[CobryWZL]

We tried to use the example (V570_Freqeuncy-precise meter.vlp) to get the flow sensors running, but it doesnt work.
 It looks like the SAMBA pulls our flow sensor signal from 24V to 9V and the 9V are to low to set the logic to "1". (since the data sheet of the samba says 17-28V for logic 1).
How can we fix this?

 

 

[kratmel]

Is it input configuration jamper in correct position?

NPN input type needed.

[Joe Tauser]

You may need a pull-up resistor on your flowmeter if it's NPN and all your other inputs are PNP (+24V = Logic 1 or ON).

Can you post a data sheet or exact part number for your flow sensor?

Joe T.