Post by rafaelbrito on The element of type 'VisuFbElemImage' could not be updated. Reason: Index was outside the bounds of the array. ^{CODESYS Forge talk (Post)}
When trying to use the Visualization ToolBox, no objects appear and the following error appears. Could you tell me what this error could be? The element of type 'VisuFbElemImage' could not be updated. Reason: Index was outside the bounds of the array. Can anyone tell me what this error is?
Last updated: 2024-12-03

Post by tvm on Cannot pass array of constant size to a function as a reference ^{CODESYS Forge talk (Post)}
maybe this would be a better approach, then you don't have to pass the constant at all. FUNCTION fun : INT VAR_IN_OUT arr: ARRAY[*] OF INT; END_VAR VAR lower: DINT; upper: DINT; END_VAR lower:= LOWER_BOUND(arr, 1); upper:= UPPER_BOUND(arr, 1); see here as well https://help.codesys.com/api-content/2/codesys/3.5.12.0/en/_cds_datatype_array/
Last updated: 2024-01-08

Post by timvh on Limiting Memory Access of an Array to Within its Bounds ^{CODESYS Forge talk (Post)}
Add the object "POU for Implicit Checks" to your application, then select "Bounds check". This will create a function which is automatically called each time an array is write accessed. In the function you can handle "out of bounds" situations. By default it will be limited to its lower or upper bound.
Last updated: 2024-03-06

Post by bjarne-pagaard on Multiple WebVisu ^{CODESYS Forge talk (Post)}
You can use the switch frame variable, but there should be a variable for each active visu user. You can put the switch frame variable in an array, and use CURRENTCLIENTID as index into the array to get what you want. The CURRENTCLIENTID is assigned to new users automagically by the Visu Management.
Last updated: 2024-03-14

Post by brouwyka on JSONByteArrayWriter string result incorrect order ^{CODESYS Forge talk (Post)}
Additional note: When doing all additions to a JSON array one after another without additions outside the array inbetween (and no more additions to the array after an item outside the array has been added) - which is not a viable solution for us as we might add items to any of the arrays at any time, but we tested regardless to be thorough - we get the following result: { "id": "machine_1", "readings": [ { "temp_mid": 153.8 }, { "temp_mid": 98.3 } ], "status": "RUNNING" } This mostly matches our expected outcome, aside from the JSONByteArrayWriter not adding indenting before closing square brackets ("]") at all. That doesn't matter for JSON of course, as it's not sensitive to indenting, but it's still a bug regardless. Also, it adds an unnecessary newline between items in the array (at least when having an array of objects, we haven't tested with arrays of primitives). I also want to reiterate that this is not a viable workaround for the issue for us - we have to be able to add to any array at any time, which should be possible according to the docs, and we are 100% sure indexes are correctly being managed and built up by the JSONBuilder and our wrapper (to track the index of each array & the latest item added to each exactly to make use of the documented possibility to add anything anywhere in the JSON at any time as long as you keep track of the returned indexes) around it.
Last updated: 2026-06-10

Post by rmarco on Generic Variables and FDB ^{CODESYS Forge talk (Post)}
Hello everyone, I am running into a highly frustrating issue in the FBD editor regarding a Function Block with generic constants (VAR_GENERIC CONSTANT). I created a FB using ST, with a generic var, useful for having a variable sized array, as follows: FUNCTION_BLOCK Coil VAR_GENERIC CONSTANT maxEvents: USINT := 5; END_VAR VAR events: ARRAY[0..maxEvents-1] OF IEvent; END_VAR These FBs have also several methods. I declare them as follows in code: VAR coil1: CDL.Coil<(maxEvents:=1)>; END_VAR and when using them in ST, I have no problems. However, when trying to use them in FDB, I do not know how to do that, as some strange misalignment happens. Here's what happens: When I add the block to my FBD canvas and assign coil1 as the instance name, the compiler throws this error: 'coil1' is not an instance of 'CDL.Coil<(maxEvents:=1)>'. Same occurs when I try to instantiate blocks such as 'coil1.turnOn' or similar. Here is what I have already tried, none of which worked: - Deleting the <(maxEvents:=1)> parameter from the text inside the FBD box. - Deleting the block entirely, dropping an "Empty Box", and typing coil1 above it to let the IDE auto-complete and format the block. - Running a full "Clean All" and rebuilding the code. I am aware that I could bypass the graphical editor by calling it in Structured Text. However, I need to keep this logic compatible to FBD. Has anyone encountered this specific FBD parsing bug with generic variables? Thanks in advance for any insights. Best regards, Marco
Last updated: 2026-06-29

Post by timvh on STRING conversions to DWORD ^{CODESYS Forge talk (Post)}
I guess that the printer expects to receive an array of byte values. So where it is described that it expects to receive: Hercules String : 1B4F513030311B7532626C61636B04 it actually expects to receive an array of bytes with the values 1B,4F,51,30,30, etc. So what you can do is create an array of bytes and assign the byte value to each item in the array: VAR abyToSend : ARRAY[0..99] OF BYTE; END_VAR abyToSend[0] := 16#1B; // ASCII Escape character, hexadecimal representation uses 16# as prefix abyToSend[1] := 16#4F; // ASCII 'O' abyToSend[2] := 16#51; // ASCII 'Q' abyToSend[3] := 16#30; // ASCII '0' // you can do the rest yourself // maybe could be created a lot smarter, but gives you an indication how to handle this. Then with the serial communication (or TCP/IP?) you can send a message with the reference to the array (abyToSend) and the number of bytes to send (15 bytes for the string you gave as example).
Last updated: 2025-02-02

Post by laurits on Max lines of code, codesys CNC ? ^{CODESYS Forge talk (Post)}
Hi, okay here's the project, it's a modified version of "CNC Example 10: Programming Dynamic CNC Paths", no need for G Code text file (i have also tried with G code text file, same problem) in "PROGRAM PLC_PRG" you can set bStart to true, and the program should start running, go to "PROGRAM CNC" and you can see axis moving. lrXpos := IoConfig_Globals.XAixs.fSetPosition; lrYpos := IoConfig_Globals.YAxis.fSetPosition; Now you can can change the number of movements in the the "PROGRAM PLC_PRG" From this number of movements in "program PLC_PRG" BUF : ARRAY[0..32010] OF SMC_GEOINFO; xp : ARRAY[1..32000] OF REAL; yp : ARRAY[1..32000] OF REAL; to this number to this number of movements BUF : ARRAY[0..132010] OF SMC_GEOINFO; xp : ARRAY[1..132000] OF REAL; yp : ARRAY[1..132000] OF REAL; Now if you start the program again you should see an error in the "sMC_Interpolator: SM3_CNC.SMC_Interpolator;" function block Let me know if you can not get it running.
Last updated: 2025-06-03

Post by mxj262 on FB having single input but initialized with Array ^{CODESYS Forge talk (Post)}
I am adding elements of an ARRAY using pointer to access each element inside a FOR loop and the FOR loop does not stop! What is the right way to use pointers in such case?? I have another loop that is not using pointer and it stops but the loop using pointer keep on adding. METHOD FB_Init: BOOL VAR_INPUT bInitRetains: BOOL; // TRUE: the retain variables are initialized (reset warm / reset cold) bInCopyCode: BOOL; // TRUE: the instance will be copied to the copy code afterward (online change) END_VAR VAR_IN_OUT // basically REFERENCE TO window_buffer: ARRAY [*] OF INT; // array of any size END_VAR THIS^.windowPtr := ADR(window_buffer[0]); THIS^.windowSize := UPPER_BOUND(window_buffer, 1) - LOWER_BOUND(window_buffer, 1) + 1; FUNCTION_BLOCK FB500 VAR_INPUT END_VAR VAR_OUTPUT END_VAR VAR windowPtr: POINTER TO INT; windowSize: DINT; currentIndex: UINT; element1:INT; element2:INT; i:INT; j:INT; sum:DINT:=0; END_VAR element1:=windowPtr[0]; // read the first element of the Array dynamic memorry element2:=windowPtr[1]; FOR i:=0 TO (TO_INT(windowSize-1)) BY 1 DO // this loop does not stop Sum:=sum + windowPtr[i]; END_FOR FOR j:=0 TO 5 BY 1 DO // this loop stops j:=j+1; END_FOR https://ibb.co/k3DhkZT
Last updated: 2024-05-06

Post by levih on FbHTTPs_Get how to get data from a website and use it in codesys ^{CODESYS Forge talk (Post)}
You get an array of DWORD into your receive buffer. You need to process this into usable data, before you can fit it into your DUT. I've made it work using FbWrite_ToIEC_ByRule in stead of Fb_JSON_ParseAndModify. I've attached images of the code. You receive the data into ARRAY[0..1023] OF DWORD. Then you use that array as the input for fbWrite_ToIEC_ByRule. To get the output from this you define a rule to fit the expected data structure including nesting levels. The you feed the rule into FbWrite_ToIEC_ByRule and then you can set the output to be of your DUT type.
Last updated: 2025-06-16

Post by simover on TCP/IP client ^{CODESYS Forge talk (Post)}
I want to send a string to a tics TCP/IP server. I got i working with the Net Base lib. for communication good with this tcis i need to by array of byte I want to include a string in the third position of the array TCIS_Send[1] :=254; //this valus is fix for evry communication TCIS_Send[2] :=80; //this valus is fix for evry communication TCIS_Send[3] := ; here I put my and my string is lik this 5806509-DRAP10#AB#3452302073 TCIS_Send[4] :=252; //this valus is fix for evry communication
Last updated: 2023-12-18

Post by nano on Issues with Modbus Slave with Raspberry Pi ^{CODESYS Forge talk (Post)}
in the codesyscontrol.cfg or codesyscontrol_user.cfg you have to declare whoch comport-ports from runtime are used. please tell us how the comport is called in linux an post the codesyscontrol.cfg files also write down here, which parameters are used in the python-script and what is parameteized in the modbus-master-comport of your codesys-application. mostly the errors occurs in ine of these areas
Last updated: 2024-07-11

Post by timvh on Stack overflow with really simple function ^{CODESYS Forge talk (Post)}
You have declared the function block in a function and call the instance also from a function. This is not correct, because a function is initialised with every call. The http client function block should be declared as Global Variable if you want to cal it from a Function, but probably it is better to declare it in a Program and also call the instance of the http function block from the same Program.... The variables of a Program are not initialised with each call.
Last updated: 2024-09-20

Post by gabrielarffa on Modbus TCP/IP having problems with global variables ^{CODESYS Forge talk (Post)}
I'm using Modbus TCP/IP to communicate Codesys with Elipse E3 as the master for a college project. I have made a list of global variables to organize the programming in two different POUs. The problem is, when I try to do the mapping of variables, the program informs me of an error due to the identifiers having a "." on their names. Do I have to reorganize my code to make it an unified block or is there a way to declare their names without changing all the code structure?
Last updated: 2025-05-20

Post by gabrielarffa on Modbus TCP/IP having problems with global variables ^{CODESYS Forge talk (Post)}
I'm using Modbus TCP/IP to communicate Codesys with Elipse E3 as the master for a college project. I have made a list of global variables to organize the programming in two different POUs. The problem is, when I try to do the mapping of variables, the program informs me of an error due to the identifiers having a "." on their names. Do I have to reorganize my code to make it an unified block or is there a way to declare their names without changing all the code structure?
Last updated: 2025-05-20

Post by ojz0r on INT_TO_WORD function not working ^{CODESYS Forge talk (Post)}
That calculation will not work the way you expect it to. If PumpFillSpeed is limitied to 0-50 then the only whole number would be 50/50 = 1 everything else is 0.0-0.9999... and since you are using word and integer only 50 would work since there is no representation for mantissa in integer values. Declare a temporary real variable and do the calculation and then do a REAL_TO_WORD in the DRV2Speed assignment.
Last updated: 2024-01-26

Post by brouwyka on JSONByteArrayWriter string result incorrect order ^{CODESYS Forge talk (Post)}
Hi @TimvH, As discussed in our email contact, your example does not actually test/reproduce the bug I am describing: Adding to the JSON builder on later cycles works fine. Your example works because you do the following: 1. You finish the first cycle (xFirst) with adding an object to the array with 2 fields; 2. When the next cycle is triggered (xAdd), you immediately start with adding another object to that array. This works fine as the last thing you did before #2 was the addition of the array and an object to it. To reproduce the bug you should be doing the following instead, as I showed with the code I shared with my first post: 1. Create the array - save the index that is returned; 2. Add an item, either a primitive or an object, to the array; 3. Add an item outside the array (anything: a primitive, a new array, a nested object, etc); 4. Add another item to the array using the index you saved at #1. You will now see, as I shared in my initial post, that the second item is placed completely outside the root JSON object. This also happens to anything else you try to add after step #4: everything after this point will be added outside the root JSON object: the JSON is completely broken. Important to note is that this not only happens with arrays, but also with nested JSON objects. Once you add something outside of a nested JSON object, you can no longer add anything to that nested JSON object, as that causes the exact same bug. This also applies to arrays of objects, so if in your test you had tried adding a new key-value pair to the first nested object in your array after you created the second nested object, you would also run into this bug. It seems that the JSONByteArrayWriter (I haven't tested the other writers in the JSON Utilities SL library, so I don't know if they suffer from the same problem) simply does not handle any JSON fields that add brackets (so arrays with "[" & "]" and nested objects with "{" & "}") well, and closes them prematurely instead of checking if any later JSONElements in the JSONData's array belong to any of these bracketed fields. After reviewing the objects & functions of the JSON Utilities SL library, my guess is that either the JSONByteArrayWriter linearly goes through the array of JSONElements in the JSONData and only checks the diParentIndex of each JSONElement in direct ascending order, OR if it does use the JSONElement.GetChildren(); method, that this method is either broken and doesn't give all children correctly to the writer. Neither explains why everything completely breaks, and you cannot even add to the root JSON object anymore, however, so there is probably more than just that going wrong in the writer. To me, after a full week of testing and attempting workarounds, this seems like a bug in the library that needs to be fixed by Codesys, as I cannot see anything wrong in the JSONData constructed by the JSONBuilder - this seems purely a problem in the writer.
Last updated: 2026-06-15

Post by timvh on Sorting array of any-sized structure ^{CODESYS Forge talk (Post)}
Look all the way at the end of the link below. This provides a way to use arrays with various lengths: https://content.helpme-codesys.com/en/CODESYS%20Development%20System/_cds_datatype_array.html
Last updated: 2023-08-18

Post by jegerjon on Find index based on values ^{CODESYS Forge talk (Post)}
Hi, I need to figure out witch indexes of an Array containing the highest and lowest values. Typically search for the 5 lowest values and result the indexnumbers containing the 5 lovest values. is there a library for this, or codeexample?
Last updated: 2023-08-20

Post by jegerjon on Find index based on values ^{CODESYS Forge talk (Post)}
Hi, I need to figure out witch indexes of an Array containing the highest and lowest values. Typically search for the 5 lowest values and result the indexnumbers containing the 5 lovest values. is there a library for this, or codeexample?
Last updated: 2023-08-20

Post by drml on Array to String ^{CODESYS Forge talk (Post)}
If a size is not specified, CODESYS allocates 80 characters by default for a string. After 7 seconds, does your Json_string contain all of your 20000 key/values? Or is the result truncated to 80 characters?
Last updated: 2024-07-19

Post by mmpl on Array to String ^{CODESYS Forge talk (Post)}
Hi Thank you for you reply. Yes I can concatenat longer string. I am using string_Util_Intern libraray for concat. The issue is abot plc performance. It takes 7 second. I am looking to improve time.
Last updated: 2024-07-23

Post by timvh on Readable IO names ^{CODESYS Forge talk (Post)}
IF you create an ENUM {attribute 'qualified_only'} {attribute 'strict'} TYPE E_IO : ( FIRST := 0, SECOND := 1 ); END_TYPE You should be able to access the array items like: IOCard_OUTPUT[E_IO.FIRST]
Last updated: 2024-09-28

Post by rckalex on Changing Trace Variable at Runtime ^{CODESYS Forge talk (Post)}
Is it possible to change the variable being traced during runtime? I would like to use the CURRENTCLIENTID in combination with an array of real numbers to alter the traced variable in a display window, without needing to create separate visualizations for each variable.
Last updated: 2025-01-22

Post by ton on Length of string and Array of bytes ^{CODESYS Forge talk (Post)}
When you use a string value 0 will be the end terminator. Everything after this will not be in the string. I guess byte 2394 has a value 0.
Last updated: 2025-04-01

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