Pulse input to product output speed?

Hi to all,

We have installed a sensor which counts the number of bottles coming out of the conveyor. My question is how can we compute for the actual output of the conveyor in terms of bottles per minute, bottles per hour, etc. using the pulse coming out of the sensor sensing the bottles.

Hope to hear from all of you soon.

Thanks

Do you want instantaneous bottles/minute or the actual number of bottles in the last minute ? What will the information be used for and do you need fractions of bottles/min ?

Yes I want it to be instantaneous bottles/minute. It will be use for monitoring the bottles's speed that's coming out of the conveyor. Hope to hear from you. thanks.

Glass Container Production Recording

Hello omarq5,
We have been doing this for many years. Apart from many
systems in Australia we have several in Asia. In most cases
we do Production Recording as a "Give away" as part of our
Forehearth Control Systems.
We do not calculate an instantaneous Machine Speed (Bottles per min) but rather count bottles or shear cuts for each and every
minute. Machine speed is then calculated either every monute
or more usually every 10 minutes.
We usually provide Final Pack, Hot end Losses, Cold end Losses,
Total Losses in addition to M/C speed and Possible all on an
hourly, shift and daily basis.
The calculations are really very simple but have evolved over
many years to provide the most usefull information.
These days we use Siemens S7-400 PLC's for Forehearth Control.
If only doing Production Recording S7-300 or S7-200 would be OK.
In Asia we mostly work through Emhart Glass in Singapore.
Let me know what you want to do in more detail and I will be
pleased to assist.
Regards............John Gaunt

Hi John,

Thanks for replying. Could you give me a sample plc ladder diagram (using S7-300 or s7-400) on how to implement this logic?

Hope to hear from you soon.

thanks,

Hi omarq5,
If you send me a private email with your normal
email address I will send you some sample programs.
Regards......John Gaunt

I was wondering, why can't you upload to the forum so others can see the examples?

Hi rsdoran,
I have been working on a document to send to omarq5 and
so far it is 30 A4 pages long. It just happens that I have
been involved in what omarq5 needs to do for more than 30 years so
rather than simply answering his question I will give him the
benefit of my experience pointing him in the right direction
to do the job properly.
The simple answer to his question is if you set up a bottle counter and count for one minute you have the Bottles per minute. Count them for an hour and you have bottles per hour etc.
In practice it is found to be best to count them for each of say 4 or 5 minutes and average them to produce a current average bottles per minute.
Once I have completed the document for omarq5 I could try to attach
it here of it isn't too large for PLCS.
Regards.....John Gaunt

another good way is to count bottles (increment a dataword) for 10 seconds, then on the time up move the count into a sequential set of words. i.e. move dw104 to dw105, dw103 to 104, dw102 to dw103 etc.
in other words shift them down, let the last drop off then add the count to Dw100 & reset the count so you end up with 6 dw each with a count in for 10 secs, add all 6 words this gives you a count over a one minute span, the beauty of this is when no bottles are running the total falls as 0 is put in first word so the count falls every 10 seconds & rises every 10 seconds, this gives you an almost instant (well every 10 seconds)count.

Glass Container Production Recording

Hello omarq5,
Attached is a writeup I have done for you with sample
Production Recording programming. The M/C speed is updated
every minute which seems quite satisfactory in practice.
We monitor M/C speed by counting the shear mechanism (shear cuts).
We do this either by adding a proximity switch to the shear mechanism or mor usually these days getting a shear pulse out
of the I.S. (Glass Forming) machine.
Of course the Shear Cuts must be multiplied by the number of
Gobs (of glass) per cut to produce M/C speed (Bottles per minute)
Feel free to contact me if you have any questions.
Regards...........John Gaunt