Filling using weighing cells

Hello...is anyone here have an example ladder; PLC omron for filling system using weight cells method.Any suggestion links also work for me..

Could you give us the communication interface for the weight cell going to the PLC?

I'm not sure what communication interface that the system used...but I'm using a load cell brand dacell(CB1-K015)which give the signal to PLC either high or low.Here is the sequence process that i have to do.

1)A valve opens, allowing for the milk to flow into the bottle.
2)As milk flows into the bottle, an accurate balance will continuously measure the weight of the bottle and the milk filling it. The output from the balance will serve as an indication of the milk level present in the bottle. The milk will continue to flow until the desired milk level (1L) is obtained.
3)When the desired level of milk has been filled into the plastic bottle the balance alerts the system that the desired level of milk has been reached. Consequently, the PLC sends a stop milk signal to the valve controlling the flow of milk, thus stopping the flow of milk to the bottle.

okay here goes.....i work alot with filling machines for milk:-

1. bottle stop lets bottles in
2. photocell detects bottle present on station
3. weight is tared to zero with bottle present
4. if your valves have a coarse & fine fill then fine fill opens for 200g to stabilise bottle
5. coarse fill valve opens until 200g from target weight
6. fine fill opens until target weight is achieved
7. valve is completely closed but inflight weight (milk in mid air between valve seat and bottle) is measure
8. in flight weight is deducted from final fine fill weight e.g. if inflight was 8g then final fine fill will become 192g.
9. if target weight has been achieved then a cap is released and the bottle is capped
10. the station is zeroed then we go back to step 2.

The whole program works around using a shift register...although i am not familiar with omron PLC's at all.

hope this helps..

LH

Thanks for the reply...actually this is my first project...so i'm not very familiar with filling using weighing cells and also i'm a beginner in PLC. If anyone here got an example ladder. I really appreciate that.It was a big help for me.

hai....

1.let me know from loadcell to converter ,plc omron read analoq input or rs232 comm
2.model omron u used it
3.analoq input mV or mA
4.for the ladder rs232 comm
a.non protocol=used send n recived ladder
b.protocol = used cx protocol software to configured


eliskasim
kluangjohor

Duo said:

Thanks for the reply...actually this is my first project...so i'm not very familiar with filling using weighing cells and also i'm a beginner in PLC. If anyone here got an example ladder. I really appreciate that.It was a big help for me.

Click to expand...

Start with your hardware first. For someone to help you with the ladder we need more info. Look again at what Longhorn posted. This is the most common way to do this process. Most important detail is your interface between your weight controller and PLC.

At a minum you should have 2 discrete inputs to the weight controller and 3 outputs from the weight controller. THis applies if you are not using some form of serial/ethernet comms.

You need to tell the weight controller when to tare. When to start measuring.


You need from the weight controller when to turn on fast feed, and when to turn on slow feed and when everything is done.

You also need to take a hard look at your rate. How fast do you want to fill these milk bottles.

Ok....the load cell is connected to the digital indicator(SM110). Output from the load cell will be amplified at the digital indicator amp.The voltage is in milivolt(mV)and output from the digital indicator(which is also in mV) will be the input to the analog input card at PLC. I'm using a CJIM.

simple program cj1m

1.analoq address(word) check at i/o table list
2.analoq word convert to dm
3.dm x multyplied (max weight) / (rated range unit)div

eliskasim
kluangjohor

@eliskasim....i'm sorry for asking...but can you give me an example about this one or more details about this:

1.analoq address(word) check at i/o table list
2.analoq word convert to dm
3.dm x multyplied (max weight) / (rated range unit)div

I'm not really understand about that...but anyway...thanks for the reply...really appreciate that

basic program for weight culculate

View attachment weight load cell.pdf

try it..for the filling program more easy used shift register to running program...


eliskasim
kluangjohor

@eliskasim...thanks for the example...really appreciate that..
What is the meaning of #2764 and #8 ( for the rated unit)...not really understand..sorry..can you give more detail about rated unit?....and here i attach the flow chart for the system...just in case for you to refer..anyway..thanks again

analoq value represention for input and ouput

analoq 4 to 20mA
range
unit
1.overflow > = 22.815mA 32767
..........................................
2.overrange 22.810 32511
20.00005 27649
..........................................
3.ratedrange 20.000 27648
16.000 20736
4.000 0
..........................................
4.underrange 3.9995 -1
1.1852 -4864
...........................................
5underflow <=1.1845 -32768
..........................................

standard culculate

regards
eliskasim
kluangjohor