Nyame Ephraim

Hi, please can somebody help me elaborate this ladder logic project ?

32 posts in this topic

Hi please, i got a ladder logic project here that a uploaded from a PLC, I please i need more elaboration on this ladder logic project

please the attached pdf below 

 

thanks 

PLC1.pdf

Share this post


Link to post
Share on other sites

??? there is not much to say about what you have provided, do you have the subroutines as well?

Share this post


Link to post
Share on other sites

Hi thanks for the reply 

the program includes the subroutines in that pdf 

from file 165 is subroutines 

Edited by Nyame Ephraim

Share this post


Link to post
Share on other sites

ok i see them now, maybe someone can help you with this but its not me. good luck.

Share this post


Link to post
Share on other sites

Sorry, that looks like a large task, too much to tackle on my own time right now.

Share this post


Link to post
Share on other sites

I'm not sure what you are looking for, but I see a program with absolutely no documentation.   That usually happens when someone uploads from the PLC without having an existing program file on the PC.  Until recently with the later Logix controllers, all documentation was stored in the program file created in the programming software.  Uploading without that will just give what you have shown.  I would suggest trying to find an existing program file on a PC.  If this was contracted out, you may be able to contact the integrator.  Most of us keep files from our previous projects.  Other than that, your only option is to go to (hopefully existing) drawings.  You will have to methodically go to each real world input/output and document their purpose.  From there you have to work backwards in the program determining what each register and bit does and documenting along the way.  I did notice real world outputs in ladder 5 and many of the N register bits are just buffer bits and directly activate those outputs.  Figure out one and you get the other!  Two for the price of one.  Unfortunately this is a long and drawn out process that could take days to complete.   In addition, without information on the real world I/O there is no way for anyone to really be able to help you figure out what does what.  Unfortunately you have a lot of work ahead of you!   I'm sure if you get stuck anyone on this forum would be happy to help.  The program looks to be fairly straight forward so you dont have to worry about complexity.  Could be a good learning experience.  I'm sure that's what you wanted to hear!

Edited by PLCMentor.com

Share this post


Link to post
Share on other sites

Hello Sir thanks for the reply.

please let me use this opportunity to brief. i was called to check on this control panel, the human machine interface is bad that is panel-view 600. the main function of this system is to measure a required quantity of chemical into a mixing batch, for example the operator may require 1700 gallons he will input values in the HMI and press the start button once the amount gets to 1700 gallons the control valve will switch off automatically. the system has about 5 flow transmitters operating. 

now since the Allen Bradley panel-view 600 is bad, my ideology was to upload the existing program from the PLC study it and see how i can create the same function for another HMI

from you feedback, please it maybe i did not get you well, does it mean that  the program i uploaded from that PLC is not related to the application i have explained ?. 

the are no diagrams for this control system nor any project files for the ladder logic diagram, nothing was documented.

i have writing to the manufacturer hoping he responds.

best regards.

 

 

Share this post


Link to post
Share on other sites

The file you uploaded from the PLC is what's running the process, but it's not documented so it's difficult to identify what's going on.

Does the HMI power up at all? If so, do you have the software to upload the runtime file from the HMI? You need Factory Talk View Studio for ME. If so, that would be a far better resource for replacing the HMI if it's a new enough software version to be decompiled and the OEM didn't password protect it.

Share this post


Link to post
Share on other sites

Hello Sir, 

thanks for the reply, the HMI does not  power up at all.

Share this post


Link to post
Share on other sites

I hate to say it, but without the source files you have your work cut out for you. Do you have pictures of what the screens were and what they displayed?

 

The best possible outcome is that whoever built the machine is still around and you can get the source files from them.

Share this post


Link to post
Share on other sites

Sir, i think before talking of replacing the HMI, i should get some better understanding how the program functions, for example i need to create an application in the HMI that enables the operator to target the quantity of product he need, like when he inputs 1000 gallons, once its achieved the valve switches off automatically ! 

so please i need some guidance on how to approach this task

 

Share this post


Link to post
Share on other sites

As mentioned above, someone with time on their hands will need to trace out the code and figure it out a line at a time. I can't do it for you on company time or on the company laptop and I don't have the software to do it on my own.

Share this post


Link to post
Share on other sites

nope, before i visited the location the HMI was not powering up.

i have written to the company who did the job. requesting for some documents they are based in Italy

 

  

Share this post


Link to post
Share on other sites

thank you very much sir'

you have made enough effort to encourage me , sincerely i appreciate .

thanks once more!

Share this post


Link to post
Share on other sites

Have you gotten anything back from the machine builder? You really need the *.apa file for the HMI for this project but you should try to get their copy of the *.RSS file too so you get the documentation for future use.

Share this post


Link to post
Share on other sites

Hi Joe, 

i have written to the company. but no respond yet. i even called the technical support center, it seems the receptionist is not all that conversant with English language, how ever she said i should get back to her by 2 pm Italian time today.

 

Share this post


Link to post
Share on other sites

not sure what the big deal is.

if production is important to you, you would make darn sure to have all schematics, BOMs, all configurations and applications backed up long before disaster strikes.

that is called preparedness and it one of key indicators of competence. 
then when problem happens it is not end of the world - if HMI is defective, replace it an load application from your backup. 

if you don't have backups at the time of need, well... you get the point.

if you want to keep production running, you don't have much choice now, deal with vendor or get someone else to reprogram system that you have... or create completely new one. 

using what you got will require some reverse engineering. program is without any documentation but - it is rather simple, with plenty of logic repetitions, which dramatically reduces effort.


i would say start with commenting I/O and work from there. for example focus on tags or addresses used most...

1 person likes this

Share this post


Link to post
Share on other sites

Hi sir, thanks for the reply.

am working hard to get the documents.

Share this post


Link to post
Share on other sites

Hi, so far  i got some documents from the manufacturer, while trying to study the documents, please i will still need more elaboration from this forum

thanks 

electrical diagrams.pdf

Share this post


Link to post
Share on other sites

So if that is the PLC program that they forwarded to you then that is unfortunate as it also does not have any descriptions in it.  I would again request they send you a copy of the program with descriptions.  If you get it, make sure you put it somewhere safe so that it will be available in the future.  In addition, I would ask them to send you a copy of the Panelview configuration or backup.  With that you can restore the existing HMI configuration to a new Panelview.  While panic is a little harsh, his primary points are valid.  I understand that your facility probably does not have experienced controls people that might have been aware that this was an issue.  Now that you do understand this, I would suggest you go through your plant and catalog other machines that may be lacking proper documentation.  Get ahead of the next problem by making sure there is a documented copy of each program and configuration files for all of the configured electronics in your facility.  On this system, if you cannot get a documented copy of the program, you at least have a copy of the drawings so documentation can be added.  Your fist step there is to go to each input and each output in your program and add the description shown in the electrical prints.  Nobody on this forum is going to do that for you.  They will answer questions and some may be willing to take care of it for a fee.  I would suggest locating a local integrator to help you work through this issue.  It sounds like you really need someone to look over your shoulder as you work through this.

1 person likes this

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now