Hello, please its possible to control flow rate using flow-meter frequency ?

Hello, please its possible to control flow rate using frequency mode of a flow meter ?

if yes, how is it done for a PLC like Micrologix ?

i will also appreciate if anyone can help with demonstrated examples

thanks

The first step is to convert the pulse frequency to a flow rate. There are many posts on this forum illustrating that procedure.

After you have the flow rate you would control flow as if you had a direct flow signal.

OK Sir, thanks for the reply.
am new to this type of project. please i will need more elaboration.
i guest will need analogue card to read the pulses from flow meter.

i need to understand the necessary conversions required to convert the pulse frequency to flow rate

thanks
Frequency output: full scale frequency 2...1000 Hz (fmax = 1250 Hz), on/off ratio 1:1, pulse width max. 10 s

Analog input won't measure pulses. You likely need to use a high speed counter, depending on your flow rate and pulses/volume configured.

Some PLCs, like the 24VDC input MicroLogix have HSCs built-in.

If you aren't tied to AB, an S7-1200 has pulse inputs that will handle that IIRC.

the first thing you need to do is to determine the capability of the flow meter.
what is the lowest flow it will work with?
what is the max flow?

Don't buy a lot of stuff only to find out the meter will not work below 5 gallons per minute or more than 40 gallons per minute. Read the specs.

james

nyameephraim said:

Hello, please its possible to control flow rate using frequency mode of a flow meter ?

if yes, how is it done for a PLC like Micrologix ?

i will also appreciate if anyone can help with demonstrated examples

thanks

Click to expand...

With all due respect, you have a history of asking for others to basically do (what appears to be) your job for you. It's one thing to need some help understanding certain parts of an application and something completely different to ask for "an example" which is basically giving you something to reverse engineer. I wouldn't normally take this stance except that in your last post you gave attitude to people when they questioned what you were wanting them to do and appeared to get mad because some of them weren't helping you. As I said in that post, you need to hire a consulting engineer who knows what they are doing to design a system for you. You are trying to get something for free and that is not the intent of this forum. If you can't do the work, find someone who can but be prepared to pay for it.

Hello thanks for the reply. point of correction, please i did not get mad because they were not helping me, but someone made a wrong approach which i corrected.
basically if i get stack in what am doing am free to ask questions, i may ask it wrongly, or go excess, if you pick interest in contributing it makes me learn.
i have seen several examples sent to people in this forum.
i agree am a beginner when it comes to programming, so i still want to learn, i appreciate any contribution made in any question i ask. but it does not mean the person is doing my job for me.
there are other areas in control were people get daily contribution from me, i wont say am doing their job for them rather am helping them with my contribution to succeed in their project they have at hand.

its but normal that in the opposite direction you may see 6 as 9.
we respond to questions due to the way we think.

I"m not going to drag my point on except to say "questions are meant to be answered or ignored, if you got no contribution let it go." (a reply you posted on February 13th 2019) does not look like a "correction" but rather an inappropriate response to someone expressing what they think about what you were asking. It was viewed as disrespectful to someone who takes time out of their busy day to help others who share the same enjoyment of working with automation systems.
You can spin this as you like but once you post on a public site you open yourself up to others expressing their points of view on your posts. If you were doing this as a hobby I would have a different opinion of your questions but (it appears) you are doing this as a job and what you are asking for people to do at the level you asking them to do it (show their work by way of a functioning example) amounts to asking people to do at least part of your job.
Having said all of that, this is simply my viewpoint which I will only express, not impose nor will I show any disrespect to anyone who chooses to help you at any level (even if someone chose to write a program for you).
I will leave with one last repeated statement (and then I will not address this subject again), for what you are asking at the level you are asking (the amount of work), you should be hiring a consultant to design the system for you. You aren't asking for help with some of the details but rather pretty much the majority of the program.


If I have offended anyone one, I apologize. It was not my intent and again, this is simply my view point.
Best regards.

I have reread your post - "is it possible to control the flowrate using a flow meter"

Yes, but you will need other equipment to do it. a flow meter only reads flow, it does not control the flow.

Again !, you must read the specs of the flow meter you intend to use to see where the cut off points of the meter are. ALSO, the meter must be compatible with the substance you are going to control.

show us what you have come up with and we will give pointers.
james

Many flow meters have both pulse and Analogue outputs, If you have analogue output then you will need analogue input card, put the measured flow into a PID loop & control whatever drives the flow. If you do not have the basic concepts of process control then I suggest you leave this type of project to someone that has, the results of you not knowing the basics could put other employees in harms way.