Post by open on How to create a stopwatch? ^{CODESYS Forge talk (Post)}
Hi @ph0010421, I tried the program the TimeTaken is calculated when stop is triggered. I want the TimeTaken to be continuously calculated and counting when a BOOL variable is true. I tried to program this way: Declaration: PROGRAM PLC_PRG VAR bStartStop: BOOL := FALSE; // Start/Stop button bReset: BOOL := FALSE; // Reset button bRunning: BOOL := FALSE; // Flag indicating whether the stopwatch is running tStartTime: TIME; // Variable to store the start time tElapsedTime: TIME; // Variable to store the elapsed time END_VAR Implementation: // Main program logic IF bReset THEN // Reset button pressed, reset the stopwatch bRunning := FALSE; tElapsedTime := T#0s; ELSIF bStartStop THEN // Start/Stop button pressed, toggle the running state IF bRunning THEN // Stop the stopwatch bRunning := FALSE; ELSE // Start the stopwatch bRunning := TRUE; tStartTime := tElapsedTime; END_IF; END_IF // Update the elapsed time when the stopwatch is running IF bRunning THEN tElapsedTime := tElapsedTime + T#1s; // Adjust the time increment as needed END_IF However counting of the seconds is not accurate. I tried changing the main task cycle time interval to 1000ms. The counting of seconds become slower. (see attached) Please help
Last updated: 2023-12-08

Post by paulorb on STRUCT AT %MW1000 ^{CODESYS Forge talk (Post)}
Hi I am trying to use STRUCT to parse commands from Modbus/TCP, Modbus client will fill the bytes related to a specific command (type, parameters), then PLC (Codesys) will access the command parameters. A STRUCT will simplify a lot the process of parsing the data, so I don't need to parse byte per byte, address will be mapped to a struct and I can use it for parsing the data. From what I understood, the compiler does not allow me to specify the location of the struct for a %MW register. VAR_COMMAND AT %MW1002: structGenericModbusCommand; This will throw: Bad declaration, use '%ML' for 'structGenericModbusCommand' variable But If I change it to %ML, when you go online you see that it is actually allocating the struct in another memory address. When we go online, on GVL we can see: VAR_COMMAND. structGenericModbusCommand %ML1002 commandType COMMANDTYPE %MB8016 ... %MB8020 I am not specifying a pointer or a reference it is a struct type, why is it mapping to a %MW location (random one). How can I control where it is mapping to? I need a consistent way to map STRUCT to specific modbus address. Is it possible? Thanks, Paulo Note I am using a Codesys OEM: Schneider Machine Expert Logic Builder (M241)
Last updated: 2024-08-13

Post by ofey on Symbol configuration / GVL ^{CODESYS Forge talk (Post)}
Hi! I have som variables that I communicate to a Modbus Master. These variables are declared in a "Global Variable List" where I have assigned them memory addresses. To organize this mapping I want to make a MODBUS list where I show all the variable names together with the memory address. Is there an easy way to export this list from CODESYS? Either through script or some export function maybe?
Last updated: 2023-10-11

Post by ofey on Symbol configuration / GVL ^{CODESYS Forge talk (Post)}
Hi! I have som variables that I communicate to a Modbus Master. These variables are declared in a "Global Variable List" where I have assigned them memory addresses. To organize this mapping I want to make a MODBUS list where I show all the variable names together with the memory address. Is there an easy way to export this list from CODESYS? Either through script or some export function maybe?
Last updated: 2023-10-11

Post by pietrobalint on Retain / Persistent Variables in Codesys for Raspberry Pi ^{CODESYS Forge talk (Post)}
Hi micik, I am not sure I am using well the code, because I checked the directory and there is no retains.ret file. Now I deleted the code from my project and the values are still works as persistant variables after ssh reboot it seems to me they retain as their previous value. So I am a bit confused, maybe 4.12.0.0 Raspberry Pi SL solved the persitent variable problem...
Last updated: 2024-08-20

Post by anuj9326 on OPC-UA Client connection, Linux SL /Raspberry Pi ^{CODESYS Forge talk (Post)}
hello edwin i have did the same and i could connect the opc-ua server but i dont see anything in the resources tree, in the application i linked my variables to the symbol configuration but i dont see that in the uaexpert. if i use the same application with a non linux system i can get those variables values and see the complete tree structure. What could be the problem ?
Last updated: 2024-08-21

Post by anuj9326 on OPC-UA Client connection, Linux SL /Raspberry Pi ^{CODESYS Forge talk (Post)}
hello edwin i have did the same and i could connect the opc-ua server but i dont see anything in the resources tree, in the application i linked my variables to the symbol configuration but i dont see that in the uaexpert. if i use the same application with a non linux system i can get those variables values and see the complete tree structure. What could be the problem ?
Last updated: 2024-08-21

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 egr99 on Modbus TCP Server connection is ESTABLISHED but all holding registers are value 0? ^{CODESYS Forge talk (Post)}
Hi there, Read the above description and experienced the same: Reading coil/discrete input/input register/holding register doesn't fill the mapped I/O variable. Any suggestions? Defined (see attachment): - Ethernet (with parameters according to the used Ethernet adapter of my Windows 11 laptop) - -Modbus TCP Client - - -LOGO231 as Modbus TCP Server - - -WS242 as Modbus TCP Server (WaveShare Modbus TCP <-> RTU converter) - - - -WS242_01 as Modbus Server, COM port (slave-id 1 RTU) - - - -WS242_03 idem (slave-id 3 RTU) - - - -WS242_11 idem (slave-id 11 RTU) Writing coil/holding register works from a mapped I/O variable works fine. Verification of Modbus traffic with WireShark: QUERY to and the RESPONSE of all slave-ids are correct Status of all defined is CONNECTED, RESPONSE_SUCCESS, RUNNING etc. Request counters increase with expected frequency. Error counter = 0. (To have all counters works fine I had to change Modbus TCP Client's parameter OptimizationON to FALSE). LOGO231 works fine: values in mapped I/O conform expectation WS242 without Modbus Server, COM port and with defined channels (for only 1 slave-id possible) works fine. PLC Settings: Update I/O while in stop: I see xBusy changing from FALSE to TRUE and vice versa. Always update variables: Enabled 1
Last updated: 2026-04-05

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 gatto on Read codesys version in the codesys application ^{CODESYS Forge talk (Post)}
hi, i used another way declaration: pApp : POINTER TO APPLICATION; pAppInfo : POINTER TO APPLICATION_INFO; ProjectName : STRING (24) ; CodesysVersion : STRING (15) ; code: //library : // CmpApp // IoDrvEthernet // // Get Pointer to current application pApp := CmpApp.AppGetCurrent( pResult:= 0 ); // Get Pointer to Application information pAppInfo := CmpApp.AppGetApplicationInfo(pApp:= pApp, pResult:= 0 ); ProjectName := pAppInfo^.pstProjectName^ ; //convert codesys version to string CodesysVersion := IoDrvEthernet.UDINT_TO_IPSTRING ( udiIPAddress := pApp^.udiPSVersion ) ; so i think you need to convert your dwVersion in a UDINT and after convert UDINT_TO_IPSTRING
Last updated: 2025-01-17

Post by dnordenberg on BOOL variable in OPC UA and modbus simultaneously ^{CODESYS Forge talk (Post)}
How can I have an BOOL variable that is read/write in both modbus TCP server and from OPC UA at the same time? Variables with %MX.n %QX.n addressing which is used for BOOL/coils in modbus server is not allowed in OPC UA symbol list on Schneider M251 controllers. I have already asked on Schneiders forum but there are not a lot of codesys experts over there :( So OPC symbols can't have a address and the modbus TCP server needs a address. So how should I do it then? It seems like an impossible combination. Since I want read/write access from both ways I can't just simply make a second variable and assign it the value of another since it would be a one way assignment. I also tried using VAR_CONFIG which then makes the address syntax %Q or %M in my main variable list and that fools OPC UA Symbol Configuration to allow it and then I add the complete %MX.n address of it in the VAR_CONFIG list. This semi works, I can toggle the BOOL from modbus but the OPC UA symbol seems to be read only. It displays symbol status but nothing happens when I toogle it. I think I need another way to have the variables and symbols pointing to the same bits in memory... My plan B is to write a BOOL array compare FB that saves a history bit from previous cycle and if that does not match current status at next cycle for either the OPC symbol or the modbus variable then it copies the new status over to the other. Maybe ugly but it's like my last alternative. Kind regards David
Last updated: 2025-07-14

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 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 apurv on Cannot pass array of constant size to a function as a reference ^{CODESYS Forge talk (Post)}
I have a Array of constant size defined like this Var Constant MAX_SIZE :UINT := 10; End_var VAR array : ARRAY[0..MAX_SIZE] OF INT; END_VAR Now I want to pass this array to a function by reference, Function fun : INT VAR_IN_OUT CONSTANT MAX_SIZE : UINT; END_VAR VAR_INPUT array : REFERENCE TO ARRAY[0..MAX_SIZE] OF INT; END_VAR but when I run this it gives strange Errors Error : Cannot Convert type 'ARRAY [0..MAX_SIZE] OF INT' to type 'ARRAY[0..MAX_SIZE] OF INT'
Last updated: 2024-01-07

Post by pietrobalint on Retain / Persistent Variables in Codesys for Raspberry Pi ^{CODESYS Forge talk (Post)}
Ok, I figured out that I do not call the program in the main task. Thank you for the source code, it works!
Last updated: 2024-08-17

Post by pietrobalint on Retain / Persistent Variables in Codesys for Raspberry Pi ^{CODESYS Forge talk (Post)}
Hi, I am very new in Codesys so let me apologize for my dumb question. Could you explain how to impement this code mentioned before? Thank you very much!
Last updated: 2024-08-17

Post by pietrobalint on Persistent variables are not read after initialization ^{CODESYS Forge talk (Post)}
Hi, I have Raspberry Pi 5 and I would like to use persistence manager too. But Codesys support said that Application Composer not compatibile with my runtime. Could you recommend a solution?
Last updated: 2024-09-01

Post by chrisdeloglos on Network Variables not updating ^{CODESYS Forge talk (Post)}
Thanks for the comment. I'm using Weidmueller UC20-WL2000-AC's and changing the broadcast address to match the current subnet this worked for me as well!
Last updated: 2025-01-27

Post by ojz0r on Multiple applications on one device sharing variables. ^{CODESYS Forge talk (Post)}
One thing you could do is create an object with the variable as field with a function and procedure to get the variable (read) and set the variable (write). These are then called from your program and the vizualization.
Last updated: 2025-02-20

Post by bingo on PLC Shell commands via ST Code ^{CODESYS Forge talk (Post)}
For a permanent change, you may need to update the PLC configuration file or set the IP at startup using retained variables.
Last updated: 2025-03-02

Post by tvm on Passing properties as VAR_IN_OUT variables. ^{CODESYS Forge talk (Post)}
Use a VAR_INPUT for properties. The reason for the error is that you can't get a reference to a property. Using a VAR_INPUT will copy the property to an input variable.
Last updated: 2025-03-06

Post by stribor on Passing properties as VAR_IN_OUT variables. ^{CODESYS Forge talk (Post)}
if i only use it as input variable I won't be able to update its state within the visu object. Lets say i have real value as a property, i would like the slider object to display this value and also modify it.
Last updated: 2025-04-30

Post by fleaplc on Symbol Configuration to be Build every time! ^{CODESYS Forge talk (Post)}
I'm using Symbol configuration to share PLC variables with SCADA via 3S protocol (Symbol File). All is working fine except every time I open the project.. then I need to rebuild Symbol Configuration! Why?
Last updated: 2025-05-23

Post by davidbo on AC_Datalog DataLogChannel Save Cyclic is not working ^{CODESYS Forge talk (Post)}
"Save Cyclic" is set to 30s, but in my log I can see my variables are logged every 500ms which equals the cyclic time for my Task. Why is "Save Cyclic" ignored
Last updated: 2025-07-11

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