Can arduino connect with 4-20ma cable to control dosing pump?

Using Arduino Project Guidance
1

Hello all, i am working on a company that have a water treatment plant, now i need to control the pH of raw water, usually the company using dosing pump that controlled with PLC (but not for PH, its for another chemical),i just have a basic knowledge with PLC to code a ladder diagram and now i think that i want to use arduino instead because i have experience to make a very small project with arduino (using pH meter too) and esp32

my question is, can i control a dosing pump with arduino ?

the spec of dosing pump said that the stroke of the pump can be controlled using 4-20ma analog input,and idont have any idea about that, i think if i connect an arduino with this 4-20ma cable and connect the cable to the dosing pump it will work?is it correct?

so it will be like this
arduino -> 4-20ma cable -> dosing pump
Picture1
this is image from one of dosing pump company

can you guys suggest me how am i suppose to do ? i dont have any experience using arduino with 4-20ma cable

this is the example of dosing pump that im talking about
https://www.tacmina.com/products/pump/solenoid/pzig.html#

iam sorry if maybe my question is too long,unclear and sorry for my bad english too,thank you for your attention

2

You need a line driver module. Search for "20mA DAC Arduino".

3

If ths was for a hobby situation - eg managing a little fish tank - Id say have fun.

For an industrial situation - "hobby" arduino's arent appropriate.

And where the company has existing experience with PLC's it makes little sense to introduce a totally new approach.

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4

Okay thank you,so,now I have to make a program and calibrate it ,then mapping the current output 4-20ma to control the stroke of injection amount for 0 to 300 stroke/min ?

So when it need fot the lowest, 4ma is for control 0 stroke/min and the highest ,20ma is for 300 stroke/min
It should be like this?

5

Okay thank you for your advice,i also thought about that before, honestly the reason behind this is, my company is an agent that make a system and sell the water treatment plant (WTP) from the manufacturer to other company,but my boss ask me if I could make a system that can control pH for the WTP(because he know that I have experience using Arduino), he think It will be cheaper if my company can make the pH controller system alone, instead buy it from manufacturer

honestly he ask me to design the system using any controller, i want to use PLC too,but for that I have to buy the PLC first using my money,because if I use money from the company I afraid that I will failed and ended up just wasting the money for the company because I don’t have much knowledge about PLC,so now that what make me thought to use Arduino, btw im a freshgraduate in diploma in electronics engineering and still in probation so its make me confuse because its my first job,and make me feel like an idiot if I cant make this system, although this is actually not studied when I was in college

6

The dozing pump is connected to PLC already. As I can see You can't connect an Arduino build that pump at the same time. Two current loop drivers to the same pump. No, that's not the way.

7

Or does he mean to read the pump setting?

8

Im sorry im not describe it more clear,what I mean is that the PH Controller system that I want to build is separated from the PLC in WTP,so it’s a stand alone system and using another dosing pump too,is that possible?

9

Adding one more pump and do the plumming needed? That's not how professional people would do it.

10

Hopefully not....

11

As above not really an Arduino project unless you look at the industrialised models or perhaps the PLC version that might do the job .
You also have to think about who will maintain the system and what the effect of the dosing system going wrong - loss of product , safety , cost and so on.
I would do a feasibility study and cost it out ( inc your time ) in case the bought in alternative is cheaper. .

Note you can buy modules to convert voltage to current output and visa Versa - you might need those , plus housing power supplies etc .
Don’t forget many Arduino do not have true analog output , only PWM

12

A digital to analog converter (DAC) followed by a voltage to current converter could work.

13

What is the exact pump you have?
A link to spec/data and model number please.

I would agree in this situation, dosing systems need to be bullet proof and have suitable noise and power line filtering to survive in a situation as this.

It is a great project for home use, but not with Arduino in an industrial use.

There are industrial grade Arduino products, but of course their cost is of a few magnitude higher.
Google;

industrial arduino

Tom.. :smiley: :+1: :coffee: :australia:

14

you need to go back to your boss and tell him that such a design would not be robust and hence not acceptable to the end user.
You can cite the responses you have seen on this forum from the contributors above, many of whom have considerable experience in electronics in an industrial setting.

15

So what you're saying is that you're inexperienced, have to build a control system that can affect the Public water supply and you have no mentoring or guidance to the point where you are so worried about wasting the company's money that you're avoiding the obvious solution!

Your company management sucks! No graduate should ever be put in this situation; this doesn't sound like it will end well!

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16

I guess your boss has not heard that a company must support the products it sells. The customers will NOT buy if there is no support/maintenance or even UL or FCC tags on the product.

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17

Yes, you can.

It will work by wiring an Analog signal to Arduino AI with R250. And control your Pump by wiring Arduino DO to relay board or some control board to on/off pump.

If you plan to use common ground or the same source with TX, please refer to the below,

I = 0 - 20 mA
V = 0 - 5 V
RAW = 0 - 1023

@ 4-20 mA
rawMin = 205; // 4 mA
rawMax = 1024; // 20 mA
euMin = 0; // 0%
euMax = 100; // 100%

PV = map(rawMin, rawMax, euMin, euMax);

ÎĽB.

18

Here is what you can do with an Arduino. You can build and operate a prototype device for your boss.
Several years ago my company built 30 prototype boxes for a customer. The controller was an Arduino nano and was programmed using the Arduino IDE. We built 5 boxes at a time and they were tested by customers of our client. Before all 30 had been shipped, the client had decided on a design for a commercial product that did not contain anything from his Arduino test devices. He just needed to know the parameters for what his customers desired.
You can do the same!

1 Like
19

Thank you so much for all the replies, omg I never have so much support like this in my entire life

So the conclusion is,I have to discuss this more clearly with my boss,that it isn’t appropriate and not recommended to make a standalone system using Arduino as a controller like you all said,it also can make a new problem if my design system doesn’t work and endanger the customer,and that will cost the company more than buying it from the manufacturer

So im better talk to my boss to buy from the manufacturer or facilitate me for PLC training instead try to make it with Arduino,so it can be more better for the system

But yeah I also think that designing things like this is not appropriate too for me who doesn’t have experience,especially im spend maybe 2 or 2,5 years of total 3 years of my college with online study because of covid and doesn’t have so much practical exercise during my entire college life,but its not covid fault its my fault because im not study harder, so im not confident with my knowledge and my degree too,although I wanna take that as a “challenge” for myself,but this challenge can endanger both company and customer if I don’t do it carefully

So maybe besides me doing PLC Training (if my boss facilitate me), I'll be prototyping with industrial Arduino too, and also discuss about the disadvantage about it if maybe it will used for the customer,and that's if i can make the system,i even doubt if i can do it or not

Beside that I have to think about the plumbing,power system,the panel for control it for the user if I make it alone

Honestly I don’t know what pump the company use,but the boss tell me that the pump that they are using it right now cant be used for PH control because the spec is not suitable,so he also says that I have to search about the dosing pump that can control ph of maybe 10 l/h water,so I take that pump as example

20

Sounds a bit strange. Let the PLC read the Ph sensor and modify its action upon that. Pumps are usually "stupid", just move its object. Intelligent pumps? No, hard to believe. If the boss has such technical knowledge he could design this, while sitting in the bathroom...