Post by askic on Generate FBs from source ^{CODESYS Forge talk (Post)}
Hello, I'm coming from Siemens (TIA) world and currently learning Codesys. I'd like to know if there is an option to add external txt file with ST code for creation of a function block and then use this file as a source file from which FB will be generated? For example, in TIA, there is an option add external source file to the project structure and then use option "Generate blocks from source". This would create a FB. Does Codesys have something similar? This external source file would look like this: FUNCTION_BLOCK Scaling VAR_INPUT x, k, n : REAL; END_VAR VAR_OUTPUT y : REAL; END_VAR VAR END_VAR y := k*x+n; END_FUNCTION_BLOCK
Last updated: 2024-07-31

Post by trusty-squire on parker servo and position ^{CODESYS Forge talk (Post)}
@gepert, When you say "I do not turn off power", are you saying you don't power off the drive, or you don't turn of the MC_POWER function block? I read your statement as you don't kill actual electrical power. MC_POWER should stay enabled. @Gustavo, not related to problem at all, but when you say 1.6 Nm is only enough torque to unscrew a loose bottle cap, I think that's a bit low. A quick mental math I use is 1 Nm is almost the same force as 1kG applied to a 10cm wrench. So 1.6kG applied to a 10cm wrench is still not a huge force, but more than enough to be felt if trying to turn the shaft by hand.
Last updated: 2024-08-06

Post by micik on False Notification Application Error with raspberry pi 4 ^{CODESYS Forge talk (Post)}
Hello, I have just went through all steps shown on Codesys YT channel https://www.youtube.com/watch?v=RPoPscbo3Kc And it works, I have installed PI OS 32 bit and choose Single Core. However, immediattely when I create standard project with Raspberrz pi device, "Application" is underlined, like there is an error, but in reality there are no errors, and I cannot see what are these 3 messages like shown in attachment. Aside for this red underline, everything seems to work fine. How to correct this? Thank you! Update: I have found what errors are, but not sure how to correct them: Identifier 'IoDrvGPIO' not defined Function block 'IoDrvGPIO' must be instantiated to be accessed 'IoDrvGPIO' is no component of 'IoDrvGPIO'
Last updated: 2024-09-03

Post by timvh on FB string and naming ^{CODESYS Forge talk (Post)}
I see, you want to initialize the FB. To be able to initialise it like you described, you need to add the FB_Init method to your FB. (right click on the FB, select add object --> method). Then press the arrow down, to select the FB_Init (overwrite default implementation). In the VAR_INPUT section of this method, add the variable --> Tag : STRING; Then in the code section of this method add: THIS^.Tag := Tag; // copy initial value to local variable in FB Search Google if you want to know more about FB_Init. PS, reflection + instance path, is also an option if you want to get the full name of the instance (path) of the Function Block. See: https://content.helpme-codesys.com/en/CODESYS%20Development%20System/_cds_pragma_attribute_instance_path.html
Last updated: 2024-09-30

Post by dsa28 on OPC UA subscriber not operational ^{CODESYS Forge talk (Post)}
Hello All, Hopefully I can get some help configuring an OPC UA subscriber in a CODESYS runtime in a Raspberry Pi 5 that tries to retrieve data from an OPC UA publisher (in this case running in a TwinCAT system). I tried to follow the steps described in the page to implement the OPC UA subscriber: https://content.helpme-codesys.com/en/CODESYS%20Examples/_ex_opcua_pubsub.html Seems that the example provided was created with version 3.5.16.0. Now with version 3.5.20.20 is not possible to open the complete project neither convert it. Anyway, after configuring all IPs and ports used in the OPC UA connection function block but the connection state always shows DISABLED. Can someone help me to do the proper configuration of the OPC UA subscriber? Many thanks in advance.
Last updated: 2024-10-22

Post by george32 on TCP Server ^{CODESYS Forge talk (Post)}
Dear people, I would like to create a TCP server in my PLC program. The TCP server needs to communicate with an external device. I have been searching the internet and found that the libraries Syssocket or CAA NetBaseSrv are two possible solutions to create a TCP server. From what I have read, CAA NetBaseSrv is more user-friendly to implement than the Syssocket variant. However, I am still struggling to actually implement this library. Foremost is my little knowledge about creating a TCP server and how to read/understand each function block, especially the outputs of some blocks and the types, e.g. server has an output CAA.Handle, but I cannot find the explanation of CAA.Handle. I tried to find a good document that can help me understand how to implement a TCP server, but I could not find it. Thank you in advance, George
Last updated: 2025-02-20

Post by manuknecht on Using SMC_MOVTYP.INITPOS without specifying the start position ^{CODESYS Forge talk (Post)}
I am using the object SMC_GEOINFO to generate a trajectory and move a system accordingly using the SMC_INTERPOLATOR function block similar to the sample project CNC10_DynamicPath.project. According to the documentation, the movement type INITPOS does not require a start position in the SMC_GEOINFO object, which is confirmed in the documentation of the SMC_GEOINFO object. When using the movement type INITPOS however, the motion will still start from the starting point defined in the SMC_GEOINFO object (0,0,0 if not specified otherwise). Does someone know how to resolve this or is there an example project that makes use of the INITPOS movement type without specifying the starting point? Thanks in advance!
Last updated: 2023-12-15

Post by esave on Stepper Drive with Ethercat ^{CODESYS Forge talk (Post)}
Hello everybody I am new into Codesys. I have a stepper driver (EM3E-556E) from Leadshine. I want to controll the stepper driver via EtherCat to a ST programm but I dont have any function block or anything that i can use. I only have the XML-File wich I loaded. With it I implemented the drive as a Ethercat slave and now I see these variables. (See picture) I dont know how to controll the stepper drive. And the manufacturer doesnt provide support for me. Can anybody help me or atleast tell me how they would do it?
Last updated: 2024-03-14

Post by m83coding on Raspberry Pi Codesys SPI Master ^{CODESYS Forge talk (Post)}
Hello, I am trying to control shift registers 74HC596 and 74HC165 via Raspberry PI with SPI interface. So far I did it with a Microcontroller and now I wanna upgrade my Projekt with Raspberry Pi and Codesys Software to be more flexible. I tried to adapt PiFace Function Block to just send or recive a 8 bit via SPI interface of the my Raspberry Pi. With following code (see attached screenshots) * PLC_PRG * PiFaceDigital * PiFaceDigital.write8 * PiFaceDigital.read8 I have a signal at SCK and MOSI pin of the PI, so far so good. But I really struggle with the unterstanding of the code. Is there some detailed description of each line of code? Or is there somebody in the community who can explain each line of code? Or is there a more simple way to send / recive 8 bit via SPI? Manuel
Last updated: 2024-04-23

Post by matteodigani on Error using function block "Write alias address" ^{CODESYS Forge talk (Post)}
Hi, I've got a problem using the function block "Write alias address" (ETCStack library 4.9.0.0). this is the code: EtherCAT_1(); IF EtherCAT_1.ConfigRead AND enable THEN CASE seq OF 0: exec := FALSE; T.IN := TRUE; T.PT := T#10S; T(); IF T.Q THEN seq := 1; T.IN := FALSE; END_IF ; 1: T.IN := FALSE; T(); //THIS ONE WORK CORRECTLY! WrAliasAdd.xAbort := FALSE; WrAliasAdd.usiCom := DWORD_TO_USINT(EtherCAT_1.InstanceNumber); WrAliasAdd.wSlaveAddress := 1002; WrAliasAdd.xAutoIncAdr := FALSE; WrAliasAdd.uiAliasAddress := 19; WrAliasAdd.udiTimeOut := 3000; IF start THEN exec := TRUE; ELSE IF NOT error THEN start := TRUE; END_IF END_IF IF WrAliasAdd.xDone THEN start := FALSE; done := TRUE; error := FALSE; exec := FALSE; seq := 5; END_IF IF WrAliasAdd.xError THEN start := FALSE; done := FALSE; error := TRUE; exec := FALSE; END_IF ; 5: exec := FALSE; T.IN := TRUE; T.PT := T#1S; T(); IF T.Q THEN seq := 10; END_IF ; 10: T.IN := FALSE; T(); //THIS ONE GIVES ME AN ERROR! WrAliasAdd.xAbort := FALSE; WrAliasAdd.usiCom := DWORD_TO_USINT(EtherCAT_1.InstanceNumber); WrAliasAdd.wSlaveAddress := 1006; WrAliasAdd.xAutoIncAdr := FALSE; WrAliasAdd.uiAliasAddress := 25; WrAliasAdd.udiTimeOut := 1000; IF start THEN exec := TRUE; ELSE IF NOT error THEN start := TRUE; END_IF END_IF IF WrAliasAdd.xDone THEN start := FALSE; done := TRUE; error := FALSE; exec := FALSE; seq := 99; END_IF IF WrAliasAdd.xError THEN start := FALSE; done := FALSE; error := TRUE; exec := FALSE; END_IF ; ELSE ; END_CASE WrAliasAdd(xExecute := exec); END_IF The first one slave ethercat works correctly, but the other one gives me an error. Attached the ethercat configuration of the devices. All the devices are set "Optional". So my idea is to enable only the first one (1002) and the fifth one (1006).
Last updated: 2025-10-01

Post by xcqt on Oop best practice ^{CODESYS Forge talk (Post)}
Hi all, I’m currently trying to improve my OOP structure in CODESYS and I’m looking for some input on how others approach this. I understand the basics like inheritance, interfaces, abstract FBs, methods, and properties, but I still struggle a bit with the overall architecture and what’s considered clean or scalable in bigger projects. As an example, I’m working on two different energy meter function blocks: FB_EnergyMeter_MQTT reads data from MQTT (strings) FB_EnergyMeter_Modbus reads data from Modbus (words) Both have their own Update() method and implement the same interface (something like IF_EnergyMeter). Later on, I’ll probably add more meter types, but they should all behave the same from the controller’s point of view. Now, there’s a FB_GridControl block that needs power data from these meters. I see two options here: Define the meter blocks inside FB_GridControl and call them directly (for example fbModbusMeter.UpdateModbus()). Keep the meter blocks outside and pass them into FB_GridControl as interface references, so the control block doesn’t know which specific type of meter it’s dealing with. Option 2 feels cleaner and more flexible to me, but I’m not entirely sure how to handle the data flow in that case. Should I pass the meter instance through an interface reference (REFERENCE TO IF_EnergyMeter)? Or is there a better way to link the external FBs to the control block? I’d like to hear how you structure this kind of setup or see an example from someone who has done something similar. EDIT: I think i need to do something like this fbModbusUpdateInput(wInput:= wWordValue); fbMqttUpdateInput(strInput:= strStringValue); IF bUseMqtt THEN Meter REF = fbMqttUpdateInput; ELSE Meter REF = fbModbusUpdateInput; END_IF fbControl.SetMeter(UsedMeter := Meter); Or am i thinking wrong? Thanks, Thomas
Last updated: 2025-10-16

Post by jbu0105 on Dynamic limits invaild ^{CODESYS Forge talk (Post)}
Hello, For my delta robot i wil use the MC_MoveCirvularAbslolute function. Every time that i set the execute of this function has my Axis group a error. Thats is: The dynamic limits for the movement are invalid. What can i do that this error go away? I saw a view funcitons with limit dymanics but i don't now how they work. If i use the function MC_MoveLinearAbsolute than i have no error. Does anyone know how i fix this?
Last updated: 2025-04-04

Post by jbu0105 on Dynamic limits invaild ^{CODESYS Forge talk (Post)}
Hello, For my delta robot i wil use the MC_MoveCirvularAbslolute function. Every time that i set the execute of this function has my Axis group a error. Thats is: The dynamic limits for the movement are invalid. What can i do that this error go away? I saw a view funcitons with limit dymanics but i don't now how they work. If i use the function MC_MoveLinearAbsolute than i have no error. Does anyone know how i fix this?
Last updated: 2025-04-04

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 sturmghost on Visualization using methods and cyclic ST-calls ^{CODESYS Forge talk (Post)}
I found a way to do it: You can use, for example, the text variable property of any visualization element and call a function in it. Example: Write a test POU as a function (FUN), like MyTestFun which need a boolean Variable as an input value. Now write into the text variable property: MyTestFun(bBooleanValue) Thats it. The function is called at each visu_task cycle.
Last updated: 2024-01-22

Post by micik on CAA File, how to check whether file exists or not ^{CODESYS Forge talk (Post)}
Hello, what would be the most efficient way to check whether the file exists or not. I don't want to use file.Open function, it seems like rather inefficiet operaton. I considered GetAttribute function, but this function doesn't accept filename (with path) as an input. Basically I need to check first time when program is loaded to the runtime i.e. when application is started for the first time, whether a file exists on the specific location or not.
Last updated: 2024-05-16

Post by shaunvdm on OSCAT Scale_r function not working in LD 4.60 works in LAD2 on 3.5.21sp3 ^{CODESYS Forge talk (Post)}
Hi We have picked up an issue OSCAT_BASIC.Scale_r function call not working in the old lad and FBD version 4.60. Gives no output on the function call. When we convert this to LAD2 it works. As can be see by the two screenshot in normal LD not working in LAD2 it works. Please confirm if this is an issue with Oscat or with LAD in 3.5.21sp3, is there an workaround. Regards Shaun
Last updated: 2025-10-23

Post by shaunvdm on OSCAT Scale_r function not working in LD 4.60 works in LAD2 on 3.5.21sp3 ^{CODESYS Forge talk (Post)}
Hi We have picked up an issue OSCAT_BASIC.Scale_r function call not working in the old lad and FBD version 4.60. Gives no output on the function call. When we convert this to LAD2 it works. As can be see by the two screenshot in normal LD not working in LAD2 it works. Please confirm if this is an issue with Oscat or with LAD in 3.5.21sp3, is there an workaround. Regards Shaun
Last updated: 2025-10-23

Post by kishan on OSCAT Scale_r function not working in LD 4.60 works in LAD2 on 3.5.21sp3 ^{CODESYS Forge talk (Post)}
here is formula for scale function you can impliment your own scale function Output=OutMin+(Input−InMin)×(InMax−InMin)(OutMax−OutMin) FUNCTION_BLOCK FB_Scale VAR_INPUT xIn : REAL; // Input value (e.g., raw sensor) xInMin : REAL; // Input range minimum xInMax : REAL; // Input range maximum xOutMin : REAL; // Output range minimum xOutMax : REAL; // Output range maximum END_VAR VAR_OUTPUT xOut : REAL; // Scaled output END_VAR VAR xGain : REAL; xOffset : REAL; END_VAR // Implementation xGain := (xOutMax - xOutMin) / (xInMax - xInMin); xOffset := xOutMin - xGain * xInMin; xOut := xGain * xIn + xOffset;
Last updated: 2025-10-26

Post by hyys12 on Help understanding analog in-/outputs ^{CODESYS Forge talk (Post)}
Hello. I am currently working on a WAGO PLC, where I am trying to wrap my head around how the analog inputs and outputs work in codesys. I have looked far and wide on the internet, for a general introduction to the whole concept, but I have not had any luck with finding anything that helped me understand it better. The whole goal is for me to be able to read an analog input from a temperature sensor, as well as using an analog output, to control a frequency inverter. I know these have nothing to do with each other, but that is all I have on hand right now. I am trying to program this using Ladder Diagram. The only thing is, that every video/guide I have seen/read using LD, just adds a whole lot of function blocks, to do all kinds of stuff they don't explain. My general question is, how would one go ahead and read the analog input, as well as transmit an analog output? Is there some kind of specific function block I would have to use for this, or some great video I can watch, to understand the inner workings. Is it somehow possible to see the values the PLC recieved/sends? Regards.
Last updated: 2024-12-11

Post by leafy on Use third party actuator with IO-Link Master (IFM) ^{CODESYS Forge talk (Post)}
Hey there! I am currently doing a little automation project for uni. I am trying to integrate a control-valve-system (Buerkert AirLINE Field) in my IO-Link environment. With IFM sensors, I used their pre-built function blocks, but with this third-party device, i need to write my own function block. Thankfully, IFM provides a generic sensor-fb so I can write my own FB with "extends" and "super". So far, so good. I found the IODD and some other documentation and I thought I get how it works, but somehow can't really get it to work at all. From my understanding, i need to write data into the PDO-Array. But i get confused with the indices and subindices of IO-Link. I'll append the IODD and some screenshots of my project. There is an AOI for LogicXDesigner, but I can't use that in Codesys. I hope someone has integrated a IOL-device in Codesys before and can help me with this. Cheers leafy
Last updated: 2024-04-16

Post by leafy on Use third party actuator with IO-Link Master (IFM) ^{CODESYS Forge talk (Post)}
Hey there! I am currently doing a little automation project for uni. I am trying to integrate a control-valve-system (Buerkert AirLINE Field) in my IO-Link environment. With IFM sensors, I used their pre-built function blocks, but with this third-party device, i need to write my own function block. Thankfully, IFM provides a generic sensor-fb so I can write my own FB with "extends" and "super". So far, so good. I found the IODD and some other documentation and I thought I get how it works, but somehow can't really get it to work at all. From my understanding, i need to write data into the PDO-Array. But i get confused with the indices and subindices of IO-Link. I'll append the IODD and some screenshots of my project. There is an AOI for LogicXDesigner, but I can't use that in Codesys. I hope someone has integrated a IOL-device in Codesys before and can help me with this. Cheers leafy
Last updated: 2024-04-16

Post by i-campbell on Ping By Name ^{CODESYS Forge talk (Post)}
https://content.helpme-codesys.com/en/libs/Net%20Base%20Services/3.5.19.20/NetBaseServices/Function-Blocks/IP/fld-IP.html resolve hostname and ping?
Last updated: 2023-08-24

Post by smartcoco on Visualization using methods and cyclic ST-calls ^{CODESYS Forge talk (Post)}
I think what you want is a declaration period function for the page, but unfortunately CODESYS does not have it.
Last updated: 2023-10-17

Post by jerry-sorrells on Find Function: Object reference not set to an instance of an object. ^{CODESYS Forge talk (Post)}
Build: CODESYS 3.5 SP19 Patch 1 (64-bit) Host OS: Windows 10 Target: Linux SL I have a project with programs in Structured Text and Ladder Diagram. When I try to use the Find function, it works for the Active Editor; however, when I try to use Find for the Entire Project, I get the error "Object reference not set to the instance of an object." I know what this error means in the context of the program, but I have no idea why the find function is returning this error. The variable I am searching does not matter: it happens with all variables. Any help with this will be greatly appreciated. I generally use the Find function quite often as I am developing and not having it is really slowing me down.
Last updated: 2023-10-23

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