Post by andrax on Variable Length Array - Cannot mix variable and fixed length dimensions? ^{CODESYS Forge talk (Post)}
Arrays with variable lengths are a bad idea. This makes your system unstable and can lead to crashes. Declare your array large enough to reserve enough memory
Last updated: 2025-05-24

Is it possible to link an array of bits to an alarm group to show a lot of alarms at once? ^{CODESYS Forge talk (Thread)}
Is it possible to link an array of bits to an alarm group to show a lot of alarms at once?
Last updated: 2021-07-08

Post by damian177 on Persistence variables PFC200 ^{CODESYS Forge talk (Post)}
Hi, I using persistence variables like below: VAR_GLOBAL PERSISTENT RETAIN id_worker1: ARRAY [0..3] OF INT := [231,234,176,222]; id_worker2: ARRAY [0..3] OF INT := [211,129,125,221]; Initial values can cause some problems?
Last updated: 2023-12-08

Post by john-robinson on Limiting Memory Access of an Array to Within its Bounds ^{CODESYS Forge talk (Post)}
Thanks Tim! This was exactly the functionality we were looking for. We are already using implicit checks to check for divide by 0 errors, we will add implicit checking for array bounds.
Last updated: 2024-03-06

Post by xabier on Remove white spaces in file .txt ^{CODESYS Forge talk (Post)}
Hi, I want write a array with line break in file.txt (I attacehd the screen array) and when i check the file appear with white spaces (I attached file .txt ) Somepeople know how remove this white spaces?? Thanks you Regars XABI
Last updated: 2024-04-22

Post by fless on FB having single input but initialized with Array ^{CODESYS Forge talk (Post)}
with every call of the FB500 it keeps adding the INTs of the array to the sum variable. set sum to 0 before you start the loop.
Last updated: 2024-05-06

The element of type 'VisuFbElemImage' could not be updated. Reason: Index was outside the bounds of the array. ^{CODESYS Forge talk (Thread)}
The element of type 'VisuFbElemImage' could not be updated. Reason: Index was outside the bounds of the array.
Last updated: 2025-11-03

Post by hazarath on How extract JSONElement containing Array data ^{CODESYS Forge talk (Post)}
I want to extract each element of an Array. Can someone help me with this. When I use JSONElementToString (part of JSON Utilities SL), I am seeing output as "ARRAY" instead of actual data. Here is the JSON content that I want to read : { "value1Unit": { "units": "M" }, "data": { "stepSize": 300.23, "points": [6,8] } } I would like to read each item of the element "points" i.e. 6 and 8. Here is the code I used, // Reading the content as JSON reader ( xExecute := execute , pwData := ADR ( converted_value ), jsonData := jsonDataStorage ); // Get the JSON Element jsonDataStorage.FindFirstValueByKey( wsKey := fidKeyVar, diStartIndex := searchElem, jsonElement => jsonElement ); JSON.JSONElementToString ( element := jsonElement , wsResult := valueWstring ); The content of the output of valueWstring is shown as "ARRAY" instead of the array items i.e. 6 and 8 Please can someone help me.
Last updated: 2024-07-30

Post by micik on Reverse bytes in an array ^{CODESYS Forge talk (Post)}
Hello, I'm getting the data in Codesys that is an array of 8 bytes. From this array, I need to foram LREAL number, however, because of different endiannes I need to reverse bytes in this array and then copy to a LREAL variable. For this I'm using a loop and it works OK. I wonder if there is a built in function to do this. I have found CAA Memory library but it has functions like reverse bytes in DWORD. But it seems it doesn't have what I need. https://content.helpme-codesys.com/en/libs/CAA%20Memory/Current/CAA_Memory/Reverse-Bit-Swap-ByteWord-order/ReverseBYTEsInDWORD.html What I need is a function to reverse bytes in an 8 byte array, or something similar.
Last updated: 2024-08-22

Post by micik on Reverse bytes in an array ^{CODESYS Forge talk (Post)}
Hello, I'm getting the data in Codesys that is an array of 8 bytes. From this array, I need to foram LREAL number, however, because of different endiannes I need to reverse bytes in this array and then copy to a LREAL variable. For this I'm using a loop and it works OK. I wonder if there is a built in function to do this. I have found CAA Memory library but it has functions like reverse bytes in DWORD. But it seems it doesn't have what I need. https://content.helpme-codesys.com/en/libs/CAA%20Memory/Current/CAA_Memory/Reverse-Bit-Swap-ByteWord-order/ReverseBYTEsInDWORD.html What I need is a function to reverse bytes in an 8 byte array, or something similar.
Last updated: 2024-08-22

Post by john-robinson on Limiting Memory Access of an Array to Within its Bounds ^{CODESYS Forge talk (Post)}
Recently we had an issue regarding some simple code to calculate a rolling average. The code indexes from zero to 199 to properly store the current input into a circular buffer which then allows us to calculate a rolling average: VAR input_5s : REAL; outs_arr : ARRAY[0..199] OF REAL; i : USINT := 0; END_VAR ___ //this code runs every five seconds, calculating a rolling average outs_arr[i] := input_5s; i := i + 1; output := OSCAT_BASIC.ARRAY_AVG(ADR(outs_arr), SIZEOF(outs_arr)); IF i >= SIZEOF(outs_arr) THEN i := 0; END_IF There is a simple bug in this code where the index will be set to 0 when it has surpassed the length of the array in bytes (800 in this case) rather than larger than the number of reals in the array (200). The solution here is simple, replacing i >= SIZEOF(outs_arr) with i >= SIZEOF(outs_arr)/SIZEOF(outs_arr[0]). In this example when the index increased to 201 and the line outs_arr[201] := input_5s was called, codesys arbitrarily wrote to the address in memory that is where outs_arr[201] would be if the array was that long. I would like to find a way to wrap the codesys array inside of a wrapper class that checks if an input is within the bounds of an array before writing to that value. I know how I would implement that for a specific array, I could create a method or class that takes an input of an array of variable length, ie. ARRAY[*] OF REAL, but I don't know how to make this for any data type. I am wondering if anyone has ever done anything similar to this, or has any better suggestions to ensure that none of the programmers on this application accidentally create code that can arbitrarily write to other locations in memory.
Last updated: 2024-03-05

Post by e13740e on Parameterized Property syntax for array element processing ^{CODESYS Forge talk (Post)}
Since parameterized (indexed) properties are not possible, I decided to use architectural approach "Indexing Property Adapter" to achieve the intended goal — avoiding code duplication for validated access to array elements. Essence: Create a Function Block Adapter (FB_PropertyAdapter) that encapsulates the logic for working with a single element of the target array (e.g., with one settings structure). Declare Properties inside the adapter block for accessing each individual field of the data structure. All validation logic is implemented within the Set accessors of these properties. Data Binding via VAR_IN_OUT: The adapter block receives a reference to a specific data element from the global array through its VAR_IN_OUT section, which ensures direct work with the original data without copying. Create an Array of Adapters: In the parent POU (e.g., FB_SettingsManager), an array of these adapter blocks is created — one for each element of the global array that needs to be managed. Initialize Bindings: In a FOR loop, each adapter instance from the array is given a reference to the corresponding data element. Result: This approach allows accessing the data via the index of the adapter array, and then through the property name, which simulates the behavior of an indexed property: MyAdapterArray[Index].MyProperty Thus, the validation and data access logic is written only once inside the adapter block and is then reused multiple times by creating instances of it in an array. This completely solves the problem of code duplication while providing a clean, scalable, and object-oriented architecture compatible with standard CODESYS features. Question closed.
Last updated: 2025-10-19

Post by ihatemaryfisher on Sorting array of any-sized structure ^{CODESYS Forge talk (Post)}
In my machine's operation, I need to display multiples tables containing arrays of structured variables. The arrays change during operation, and my supervisor has advised me to write a new bubble-sort for each array. I think I can make a function to sort an array of any data type. This was my own project, and I'm a relatively new coder. I want to know the weaknesses in my approach, and a better method, if one exists. As far as I can test, the function accepts an array of a structured variable of any size, and sort it by any VAR in that structure. But it relies heavily on pointers, which I've heard are bad practice? Function call: // SORT BY BYTE-SIZED VAR IF xDoIt[6] THEN FUNBubbleSortSansBuffer( IN_pbySourcePointer := ADR(astArray[1]), // address of first byte in first element of array IN_pbyComparePointer:= ADR(astArray[1].byCompByte), // points to first byte of the comparing variable (variable you sort by) IN_uiStructureSize := SIZEOF(TYPE_STRUCTURE), // size, in bytes, of the structured variable IN_uiCompareSize := SIZEOF(astArray[1].byCompByte), // size, in bytes, of the comparing variable (variable you sort by) diArrayElements := UPPER_BOUND(astArray,1), // number of elements in array IN_xSmallToLarge := xSortOrder // whether to sort by small2large or large2small ); END_IF Function: FUNCTION FUNBubbleSortSansBuffer : BOOL VAR_INPUT IN_pbySourcePointer : POINTER TO BYTE; // points to beginning of array (first byte of first element) IN_pbyComparePointer: POINTER TO BYTE; // points to first byte of the comparing variable (variable you sort by) IN_uiStructureSize : UINT; // size, in bytes, of the structured variable IN_uiCompareSize : UINT; // size, in bytes, of the comparing variable (variable you sort by) diArrayElements : DINT; // number of elements in array IN_xSmallToLarge : BOOL; // whether to sort by small2large or large2small END_VAR VAR j : DINT; // repeat iteration over array until array ends i : DINT; // iterarte over array, swapping when necesary k : DINT; // iterator from 1 to size of structure (stepping 'through' a single element in array) dwSize : DWORD; // internal var for use in MEMUtils.MemCpy(<size>) // FOR SORTING BY BYTE VAR pbySourcePointer : POINTER TO BYTE; pbySourcePointer2 : POINTER TO BYTE; pbyComparePointer : POINTER TO BYTE; pbyComparePointer2 : POINTER TO BYTE; pbyPointerToBuffer : POINTER TO BYTE; // pointer to single byte buffer byBufferByte : BYTE; // single byte buffer END_VAR dwSize := UINT_TO_DWORD(IN_uiStructureSize); // get structure size (number of bytes) pbyPointerToBuffer := ADR(byBufferByte); // assign pointer to address of buffer byte (because MEMUtils.MemCpy requires a pointer input) CASE IN_uiCompareSize OF // depending on the size of the VAR to sort by (current functionality for BYTE and WORD/INT 1: // BYTE (8 BIT) FOR j := 1 TO diArrayElements DO // for number of elements in array FOR i := 1 TO (diArrayElements-1) DO // same thing, but row[i+1] row is included in swap logic pbySourcePointer := IN_pbySourcePointer + dwSize*(i-1); // point at #1 byte in array element[i] pbySourcePointer2 := pbySourcePointer + dwSize; // point at #1 byte in array element[i+1] // NOTE: because of memory locations, each array element is offset from one another by a number of bytes equal to the size of the structure // We can "walk" from array[i] to array[i+1] via steps equal to the size of the structure // e.g., ADR(array[i+1]) == ADR(array[i]) + SIZEOF([array datatype]) pbyComparePointer := IN_pbyComparePointer + dwSize*(i-1); // point to sorting variable in array element[i] pbyComparePointer2 := pbyComparePointer + dwSize; // point to sorting variable in array element[i+1] // using sort order (small -> large/large -> small) IF SEL(IN_xSmallToLarge, (pbyComparePointer2^ > pbyComparePointer^),(pbyComparePointer2^ < pbyComparePointer^)) THEN // This is where it gets tricky. We've identified pointers for the starting bytes of aArray[i] and aArray[i+1] // and we know the size of aArray[i]. We are going to swap individual bytes, one at a time, from aArray[i] and aArray[i+1] // this allows us to use only a single byte var as a buffer or temporary data storage // e.g., consider a structure consisting of a word, a byte, and a string. it is stored like this // |------WORD-------| |--BYTE-| |STRING------...| // astArray[1] == 1000 0100 0010 0001 1100 0011 1010 1010.... etc // astArray[2] == 0001 0010 0100 1000 0011 1100 0101 0101.... etc // performing a single swap (copy into a buffer, etc.) of the first byte of each array element creates this // astArray[1] == 0001 0100 0010 0001 1100 0011 1010 1010.... etc // astArray[2] == 1000 0010 0100 1000 0011 1100 0101 0101.... etc // incrementing the pointer adresses for the swap by 1 and swapping again swaps the next byte in each array element // astArray[1] == 0001 0010 0010 0001 1100 0011 1010 1010.... etc // astArray[2] == 1000 0100 0100 1000 0011 1100 0101 0101.... etc // continuing this from k to SIZEOF(TYPE_STRUCTURE) results in a toally swapped row FOR k := 1 TO IN_uiStructureSize DO // copy single byte[k] of array element 1 to buffer MEMUtils.MemCpy(pbyDest := (pbyPointerToBuffer), pbySrc := (pbySourcePointer+k-1), dwSize := 1); // copy single byte[k] of array element 2 to 1 MEMUtils.MemCpy(pbyDest := pbySourcePointer+k-1, pbySrc := (pbySourcePointer2+k-1), dwSize := 1); // copy buffer to byte[k] array element 2 MEMUtils.MemCpy(pbyDest := (pbySourcePointer2+k-1), pbySrc := pbyPointerToBuffer, dwSize := 1); END_FOR END_IF END_FOR END_FOR
Last updated: 2023-08-17

Post by szotyi on Array of Program ^{CODESYS Forge talk (Post)}
Hi! What is the proper and the easiest way to call programs through looping of array of programs, or pointer of program? instead of calling the programs one by one: prog1(inputX: 11); prog2(inputY: 12); prog3(inputZ: 13); similar like: VAR programsToCall : ARRAY [1..3] OF PROGRAM; END_VAR programsToCall[1] := prog1(inputX: 11); programsToCall[2] := prog2(inputY: 12); programsToCall[3] := prog3(inputZ: 13); FOR i := 1 TO 3 DO programsToCall[i] (); END_FOR Thanks.
Last updated: 2024-08-28

Post by garrian on How to write multiple coils (Modbus FC15) ^{CODESYS Forge talk (Post)}
Thanks for your reply. I belive it is contiguous, I'm writing to adress 0 to 4. Or, do you mean something else? Well, something is happening. If I on the client set adress 1,2,3 to true, only 1 is set to true on the server side. On the client side, the data is array of word. But on the server side, the coils are array of bool. Holding register is array of word on server side. Can this be a problem? Attached screenshot of how it looks at the server side.
Last updated: 2024-11-17

Post by imdatatas on Problem of assigning physical addresses to variables of type ARRAY OF ARRAY as MW and QW ^{CODESYS Forge talk (Post)}
Hello, I am encountering an interesting problem as below in SP20patch5 variable definition area. I think this is a bug. As can be seen in the attached screenshot, it assigns the same %MW or %QW address to all elements of the array. I hope Codesys team can solve this problem in the next version. Best regards, Imdat
Last updated: 2025-03-17

Post by rodberna on Library for arrays ^{CODESYS Forge talk (Post)}
Hi, I'm creating a program where I need to handle arrays, like: - Declare lenght variable arrays - [array(1..var) of "sometype"]. This is not possible in pure codesys, right? - Know array lenght, min, max, avg values in runtime - append/delete itens in an array - and so on Is there a library know for this in codesys. Is it possible to build our own libraries using some high level language like python or java script?
Last updated: 2024-01-10

Post by bertrand-major on Cancelling a selection from a "combobox array" in Visu ^{CODESYS Forge talk (Post)}
Hi Joanm, Did you get an answer from anybody in anather section ?
Last updated: 2024-07-17

Post by vladimirsmall on Send data to USB ^{CODESYS Forge talk (Post)}
Hello/ Need send some file ( for example Array of string) to USB. Which library need used for this. Thank you
Last updated: 2024-07-20

Post by pilouuu on problem OPC UA array ^{CODESYS Forge talk (Post)}
Hello, why can't I read the arrays on my PLC's UA OPC server with codesys, even though they are accessible from UA Expert?
Last updated: 2025-02-26

Post by pilouuu on problem OPC UA array ^{CODESYS Forge talk (Post)}
Hello, why can't I read the arrays on my PLC's UA OPC server with codesys, even though they are accessible from UA Expert?
Last updated: 2025-02-26

Post by eaglealex on Length of string and Array of bytes ^{CODESYS Forge talk (Post)}
Hello! I have tried read a file to the string variable. But I faced a problem - there is about 2800 bytes of information in file, but string have a limit 2393 bytes. I made two variables with same address (for automatic convertion) - string[3000] and array of bytes[1..3000]. And I noticed that array of bytes contains all information from file, but string shows only first 2393 bytes. So I have lost information. Is there really such a limitation? Or I have an error in my program and Codesys 2.3 have no limit for such kind of conversation between string and array of bytes? Thank you very much!
Last updated: 2025-04-01

Post by timvh on control loop library IIR filter ^{CODESYS Forge talk (Post)}
In the Control Loop Library package are multiple example projects, including one for the filters. Program containing: GVL.filterIIR( xEnable:= GVL.xEnableFilter, lrValue:= GVL.lrYOriginal, lrFilteredValue=> GVL.lrOutputIIR); GVL.filterFIR( xEnable:= GVL.xEnableFilter, lrValue:= GVL.lrYOriginal, lrFilteredValue=> GVL.lrOutputFIR); GVL.filterSOS( xEnable:= GVL.xEnableFilter, lrValue:= GVL.lrYOriginal, lrFilteredValue=> GVL.lrOutputSOS); GVL containing aCoefficientsA_IIR : ARRAY[0.. 4] OF LREAL := [1,-2.3695130071820376,2.31398841441588,-1.0546654058785676,0.18737949236818494]; aCoefficientsB_IIR : ARRAY[0.. 4] OF LREAL := [0.0048243433577162282,0.019297373430864913,0.028946060146297369,0.019297373430864913,0.0048243433577162282]; filterIIR : Ctrl.Filter_IIR := (palrCoefficientsA:= ADR(GVL.aCoefficientsA_IIR), udiSizeCoefficientsA:= SIZEOF(GVL.aCoefficientsA_IIR), palrCoefficientsB:= ADR(GVL.aCoefficientsB_IIR), udiSizeCoefficientsB:= SIZEOF(GVL.aCoefficientsB_IIR)); aCoefficientsB_FIR : ARRAY[0.. 5] OF LREAL := [0.01982722552692669,0.1325131219866022,0.34765965248647102,0.34765965248647107,0.13251312198660226,0.019827225526926694]; filterFIR : Ctrl.Filter_FIR := (palrCoefficientsB:= ADR(GVL.aCoefficientsB_FIR), udiSizeCoefficientsB:= SIZEOF(GVL.aCoefficientsB_FIR)); aCoefficientMatrix_SOS : ARRAY[0.. 1] OF Ctrl.FilterCoefficients_SOS := [(b0:= 1, b1:= 2, b2:= 1, a0:= 1, a1:= -1.048599576362609, a2:= 0.2961403575616683), (b0:= 1, b1:= 2, b2:= 1, a0:= 1, a1:= -1.320913430819428, a2:= 0.6327387928852787)]; lrG : LREAL := 0.004824343357716228; filterSOS : Ctrl.Filter_SOS := (paCoefficientMatrix:= ADR(GVL.aCoefficientMatrix_SOS), udiSizeCoefficientMatrix:= SIZEOF(GVL.aCoefficientMatrix_SOS), lrGain:= GVL.lrG); lrX : LREAL; lrYOriginal : LREAL; lrOutputFIR : LREAL; lrOutputIIR : LREAL; lrOutputSOS : LREAL; xEnableFilter : BOOL := TRUE;
Last updated: 2025-08-01

Post by wollvieh on Array of UDT Compare ^{CODESYS Forge talk (Post)}
use sysmemcmp. https://content.helpme-codesys.com/en/libs/SysMem23/Current/POUs/SysMemCmp.html
Last updated: 2024-04-08

Post by kislov on Table How to set row number from 1 ( not from 0) ^{CODESYS Forge talk (Post)}
Use declaration with ARRRAY [1..x] instead of ARRAY [0..x]
Last updated: 2024-05-27

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