https://forge.codesys.com/forge/talk/Engineering/thread/01846c948f/2022-01-27T19:12:19.258000ZRecent posts to Advanced pointer to struct members2022-01-27T19:12:19.258000Z2022-01-27T19:12:19.258000Zalebrijehttps://forge.codesys.com/u/alebrije/https://forge.codesys.comf29b56b9817d769321b69e58d9b6eb2007201f51

<div class="markdown_content"><p>Thannk you fajean i replied to you in the folllowing link <a href="https://forge.codesys.com/forge/talk/Engineering/thread/b64911d912/?limit=25#0c0f">https://forge.codesys.com/forge/talk/Engineering/thread/b64911d912/?limit=25#0c0f</a></p></div>

2022-01-27T15:20:21.970000Z2022-01-27T15:20:21.970000Zfajeanhttps://forge.codesys.com/u/fajean/https://forge.codesys.comacbc214ecb80cd3000640675c22e9bffe4895a0c

<div class="markdown_content"><p>To achieve what you want, you do not declare a "POINTER TO ARRAY[] OF STRING". You declare a "POINTER TO STRING". You can use the array subscript notation directly with this pointer. The array subscript notation performs dereferencing, just like using "^". In fact, ptr<span>[0]</span> and ptr^ are equivalent as far as I can tell.</p> <div class="codehilite"><pre><span></span><span class="n">PROGRAM</span> <span class="n">MAIN</span> <span class="n">VAR</span> <span class="n">INIValues1</span> <span class="p">:</span> <span class="nb">ARRAY</span> <span class="p">[</span><span class="mi">0</span><span class="p">..</span><span class="mi">1000</span><span class="p">]</span> <span class="k">OF</span> <span class="n">STRING</span><span class="p">;</span> <span class="n">INIValues1_ptr</span> <span class="p">:</span> <span class="n">POINTER</span> <span class="k">TO</span> <span class="n">STRING</span><span class="p">;</span> <span class="n">END_VAR</span> <span class="n">INIValues1_ptr</span> <span class="p">:</span><span class="o">=</span> <span class="n">ADR</span><span class="p">(</span><span class="n">INIValues1</span><span class="p">);</span> <span class="n">INIValues1_ptr</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="p">:</span><span class="o">=</span> <span class="s1">'Test'</span><span class="p">;</span> </pre></div> </div>

2022-01-27T13:30:53.818000Z2022-01-27T13:30:53.818000Zalebrijehttps://forge.codesys.com/u/alebrije/https://forge.codesys.coma764d9e282cad22a004f87cf0966db4d4f3a7955

<div class="markdown_content"><p>Hello, <br/> I would like to save some values in a structure named Test<br/> The structures is </p> <p>TYPE test :<br/> STRUCT<br/> generalinfo :general; // 2 variables as string<br/> testfreatures : freatures; // 2 variables as string<br/> END_STRUCT<br/> END_TYPE</p> <p>I'm using a pointer to the struct test <br/> VAR<br/> INIValues1 : POINTER TO ARRAY <span>[0..1000]</span> OF STRING;<br/> END_VAR<br/> INIValues1 := ADR(Test);<br/> // I want to write the values as follow<br/> INIvalues1^<span>[0]</span>.^<span>[0]</span> := 'Test';</p> <p>How can I mange to do this... I would like later only to replace the struct so my function fits for many different structures</p></div>

2020-02-27T13:49:05.994000Z2020-02-27T13:49:05.994000ZComingback4uhttps://forge.codesys.com/u/comingback4u/https://forge.codesys.comf37c6b2484fbe5536a876f55aff2137050d3b419

<div class="markdown_content"><p>Someone will correct me if i'm wrong but when you use a pointer and want to access the values directly you need to de-reference it by using the ^. The de-reference comes after the variable pointer name and before the struct member.</p> <p>So to access a pointer inside the FB you would use:<br/> Measurement^.History<span>[3]</span> := 1.0; //set a single array value<br/> temp := Measurement^.History<span>[3]</span> ; //get a single array value<br/> Measurement^.MaxValue := 5.0; //set a member variable<br/> temp := Measurement^.MaxValue; //get a member variable</p> <p>If you are trying to pass the addr of a value while still in the FB you wouldn't need the ADR() since it is already referenced as a pointer. Otherwise you are passing an address of an address.<br/> SomePointerToReal := Measurement.MaxValue; //pass the addr of a value<br/> SomePointerToRealArr := Measurement.History; //pass the address of an array<br/> SomePointerTosHisto := Measurement; //Pass the address of the structure</p></div>

2020-02-27T13:49:05.909000Z2020-02-27T13:49:05.909000Ztjarcoboerkoelhttps://forge.codesys.com/u/tjarcoboerkoel/https://forge.codesys.comf14da893cf889e4ae229f1fea68fa3ecd48ce68c

<div class="markdown_content"><p>Hi readers,</p> <p>If I have a structure called sHisto:<br/> STRUCT<br/> History: ARRAY <span>[1..64]</span> OF REAL:<br/> MaxValue: REAL;<br/> MinValue: REAL;<br/> AvgValue: REAL;<br/> END_STRUCT</p> <p>And I pass it to a functionblock as a pointer:<br/> Measurement: POINTER TO sHisto;</p> <p>How do I reference the members inside a functionblock? Is the following right?<br/> Measurement.History<span>[3]</span> := 1.0; //set a single array value<br/> temp := Measurement.History<span>[3]</span>^ ; //get a single array value<br/> Measurement.MaxValue := 5.0; //set a member variable<br/> temp := Measurement.MaxValue^; //get a member variable</p> <p>SomePointerToReal := ADR(Measurement.MaxValue); //pass the addr of a value<br/> SomePointerToRealArr := ADR(Measurement.History); //pass the address of an array<br/> SomePointerTosHisto := (Measurement); //Pass the address of the structure</p> <p>Best regards,</p></div>