• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 656
  • Last Modified:

How to write into data blok into Siemens PLC

With next code i'm trying to write in the Data Blok 11 into first byte. But i have no sauces. Can you help me to resolve the error.

Best regards
function DB_write ( dbno:Integer;dwno:Integer;var amount:Integer;var buffer):Integer;stdcall;
function DB_write;external 'w95_s7m.dll' name 'db_write';
procedure Tform1.writePLC();
ammount1: Integer;
buffmy: Word;
ammount1 := 1;
buffMY:= 1 ;
DB_read(11, 0, ammount1, buffmy);

Open in new window

  • 2
  • 2
1 Solution
Bill BachPresidentCommented:
Not my field, but I have an obvious suggestion:  Change DB_read to db_write.
pr2501Author Commented:
thank you

It's ok now.

Can you help me for the nexyt problem:
When i close app. And start agin i have next mesage:

First chance exception at $7C812AFB. Exception class EOleException with message 'Cannot expand named range'. Process Project1.exe (3248)

After clicking on continue, i get mesage error (attached picture) and after clicking on ok  it starts and it works normaly.
I need to avoid this interuption.

pr2501Author Commented:
Some explanations more:

I need to close my app, because i'm  writeing new values into buffer by changing variables into Delphi IDE. After restarting my app again and with clicking on speed button i'm writing (calling procedure for write)  . And then that error appears:
Cannot expand named range
Bill BachPresidentCommented:
Are you closing the application normally, or are you terminating it through the IDE?  Many data environments instance DLL's, create connections, and perform other tasks at startup that must also be properly shutdown when terminating.  In many cases, if you terminate an app from the IDE, these clean-up functions never get called, memory never gets released, etc., and problems can occur.  Check to see if you have to call some cleanup functions for this library, and just ensure that they are called before terminating the app in the IDE.
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Featured Post

A proven path to a career in data science

At Springboard, we know how to get you a job in data science. With Springboard’s Data Science Career Track, you’ll master data science  with a curriculum built by industry experts. You’ll work on real projects, and get 1-on-1 mentorship from a data scientist.

  • 2
  • 2
Tackle projects and never again get stuck behind a technical roadblock.
Join Now