Skip to Content

Register Login

Industry Online Support

Technical Forum

Navigation

S7-1200 liquid weighing

Created by: juha889 at: 5/19/2014 3:18 PM (10 Replies)

Rating (0)

Thanks 3

Result pages:: |; 1 | 2; |

11 Entries

Entries per page: 10 | all

5/19/2014 3:18 PM	Rate (0)
juha889 Posts: 4 Rating: (0)	Ok, here is the situation: We have button A. Somebody orders few tons of liquid by pressing it. Hundred meters away another guy sees yellow light which tells that the liquid is needed. So he starts to pour it to a vessel. While liguid is going, there is another liquid which is needed to put let's say 40kg among with the first one. If additive is added, green light turns on. And if not, red light turns on. If everything went well, ordering can be done again after a B (reset) button has been pushed. We have Load cell, converter, analog signal (volts), S7-1200 and TIA portal. How the heck do I program that
juha889 Posts: 4 Rating: (0)
Suggestion To thank Quote Answer

5/19/2014 3:52 PM	Rate (0)
Siwarexi Gold Expert Joined: 1/4/2007 Last visit: 12/5/2024 Posts: 1153 Rating: (175)	Hello juha889, What do you mean with „converter, analog signal (volts)“? Normally load cells are connected directlyto a Siwarex module (=weighing module). Afterwards that Siwarex module is sending the current weight value to a PLC. That PLCcontrols a process (e.g. control a valve to fill a vessel). There exist several Siwarex modules for different applications. Take a look to: www.siwarex.com Best regards Siwarexi

Suggestion To thank Quote Answer

5/19/2014 4:15 PM	Rate (0)
kriipc Silver Member Joined: 4/11/2011 Last visit: 10/7/2024 Posts: 132 Rating: (7)	Siwarexi Hello juha889, What do you mean with „converter, analog signal (volts)“? There are plenty of converters/load cell amplifiers.One of them.
	I'm just a human. Mistakes are allowed. Sorry for my english. Only 3 months of training and manuals :)
Suggestion To thank Quote Answer

5/19/2014 4:50 PM	Rate (0)
kriipc Silver Member Joined: 4/11/2011 Last visit: 10/7/2024 Posts: 132 Rating: (7)	juha889 Ok, here is the situation: Somebody orders few tons of liquid by pressing it. Hundred meters away another guy sees yellow light which tells that the liquid is needed. So he starts to pour it to a vessel. While liguid is going, there is another liquid which is needed to put let's say 40kg among with the first one. We have Load cell, converter, analog signal (volts), S7-1200 and TIA portal. How the heck do I program that - how is your weighing platfom or tank or something designed (few tons and one load cellvery tricky) - what is the maximum range of your scale - how precise it must be (if you use onboard 0..10V analog input (10 bit resolution), then you get precision 1024 units of full range. For example if scale maximum weight is 5 ton, then you get 5 kg accuracy. Building a accurate weighing system is complicated than a writing program. For example, floor weighing platform needs 4 load cells. Tank weighing can be done with 3 load cells. It is not so easy -> load cell + converter + PLC juha889 Ok, here is the situation: While liguid is going, there is another liquid which is needed to putlet's say 40kgamong with the first one. That is tricky with one scale. You must add liquid or additive.
	I'm just a human. Mistakes are allowed. Sorry for my english. Only 3 months of training and manuals :)
Suggestion To thank Quote Answer
This contribution was helpful to 1 thankful Users Mo.Sa

5/22/2014 8:01 AM	Rate (0)
juha889 Posts: 4 Rating: (0)	Siwarexi Hello juha889, What do you mean with „converter, analog signal (volts)“? Normally load cells are connected directlyto a Siwarex module (=weighing module). Afterwards that Siwarex module is sending the current weight value to a PLC. That PLCcontrols a process (e.g. control a valve to fill a vessel). There exist several Siwarex modules for different applications. Take a look to: www.siwarex.com Best regards Siwarexi With 'converter' I meant the weighing module. We unfortunately don't have an option to use Siwarex right now :( With 'Analog signal (volts)' I meant that the weighing module sends 0-10V voltage to plc instead of current which is usually used. But for some reasons we have to use voltage this time.
juha889 Posts: 4 Rating: (0)
Suggestion To thank Quote Answer

5/22/2014 8:19 AM	Rate (0)
juha889 Posts: 4 Rating: (0)	kriipc - how is your weighing platfom or tank or something designed (few tons and one load cellvery tricky) - what is the maximum range of your scale - how precise it must be (if you use onboard 0..10V analog input (10 bit resolution), then you get precision 1024 units of full range. For example if scale maximum weight is 5 ton, then you get 5 kg accuracy. Building a accurate weighing system is complicated than a writing program. For example, floor weighing platform needs 4 load cells. Tank weighing can be done with 3 load cells. It is not so easy -> load cell + converter + PLC We have weighing system which is in use and operates well. Three load cell, max load 8 tons if I remember right. This new system should just tell us is the additive added or not. In this case the liquid is melted stuff. Argh..difficult to explain with my 'not-so-talented-english' :D
juha889 Posts: 4 Rating: (0)	Last edited by: juha889 at: 5/22/2014 8:29 AM
Suggestion To thank Quote Answer

5/23/2014 5:07 AM	Rate (0)
kriipc Silver Member Joined: 4/11/2011 Last visit: 10/7/2024 Posts: 132 Rating: (7)	juha889 Argh..difficult to explain with my 'not-so-talented-english' :D Juha is a finnish name.If so, i am your neighbour from south (viro). juha889 Wehaveweighing system which is in use and operates well. Three load cell, max load 8 tons if I remember right. This new system should just tell us is the additive added or not. In this case the liquid is melted stuff. As i wrote: kriipc - how precise it must be (if you use onboard 0..10V analog input (10 bit resolution), then you get precision 1024 units of full range. In your case there is 3 x 8 = 24 ton of full load. By onboard 0..10V analog input resolution is 24kg. I assume, that is not what you expect. Is your weighing module adjustable or not? I mean, if you do not use full load and for example maximum load is 10 ton, can you recalibrate it? Or you have already different maximum load than 24 ton? Can you post weighing module data? For better accuracy you can use analog signal modules SM1231 (12 or 15 bit resolution).
	Last edited by: kriipc at: 5/23/2014 5:39 AM I'm just a human. Mistakes are allowed. Sorry for my english. Only 3 months of training and manuals :)
Suggestion To thank Quote Answer
This contribution was helpful to 1 thankful Users Automation-newbie

5/27/2014 2:11 PM	Rate (0)
MHasan Posts: 63 Rating: (4)	If you dont want to use siwarex modules then it will be difficult. But you can try this, load cells gives output in milli-volts. So if your analog input module supports thermocouple then you may get success.
MHasan Posts: 63 Rating: (4)
Suggestion To thank Quote Answer

5/27/2014 2:52 PM	Rate (0)
kriipc Silver Member Joined: 4/11/2011 Last visit: 10/7/2024 Posts: 132 Rating: (7)	MHasan If you dont want to use siwarex modules then it will be difficult. But you can try this, load cells gives output in milli-volts. So if your analog input module supports thermocouple then you may get success. You are not right. Load cell cant produce millivolts itself (ifstrain gaugeload cells are used; more widespread). In principle it is aWheatstone bridge.
	I'm just a human. Mistakes are allowed. Sorry for my english. Only 3 months of training and manuals :)
Suggestion To thank Quote Answer

5/28/2014 8:31 AM	Rate (0)
Siwarexi Gold Expert Joined: 1/4/2007 Last visit: 12/5/2024 Posts: 1153 Rating: (175)	Hello juha889, I recommend you to use the Siwarex WP231 module for the S7-1200 system. This module is sending the current weight value to the S7-1200 PLC. Best regards Siwarexi

Suggestion To thank Quote Answer
This contribution was helpful to 1 thankful Users Automation-newbie

|

Share this page:

Share this page on...

Follow us on