Post by elsmart on Sequential read and triggering of Modbs RTU channels in application ^{CODESYS Forge talk (Post)}
Hello I need some help understanding how to use Modbus RTU (COM port) in Codesys enviroment. I defined a Modbus Server device (slave) in device tree and added some channels to read from (function 3). Also I set trigering mode to Application. I have a POU in which I want to trigger each channel one after the other something like this (C code for better visualisation): for (int i = 0; i < channelsCount; i++) { triggerChannel(channelsArray[i]); // Start transmission while(channel.xBusy); // Wait for transmission to complete } I have found ModbusChannel function block documentation but examples are scarce. I don't understand how rising edge triggering works. What would be the best solution for achieving sequntial channel triggering? What is the common way to read multiple Modbus channels once every time a specified POU is executed?
Last updated: 2025-05-16

Post by qkkk on Device Scan ^{CODESYS Forge talk (Post)}
Hello all, I have developed a custom I/O driver in CODESYS that communicates via a Unix Domain Socket. In my DeviceDescription.xml, I have set up the following: <scan supported="true"> <scanfbinstance fbname="IOScanDevice"> The goal is to allow the user to scan for connected I/O modules from the CODESYS GUI ("Scan for Devices") and automatically populate the device tree with detected submodules.</scanfbinstance></scan> The function block IOScanDevice is implemented in the driver library and added to the main device's FB instances. However, when I initiate the scan from the GUI, nothing appears to happen the function is not executed. Is there an example project or driver (open source or from CODESYS Forge) that demonstrates a working custom scan implementation?
Last updated: 2025-05-26

Post by viksym on How to get the motor scaling value from code ^{CODESYS Forge talk (Post)}
Is there a way to see what value is set as the "Work travel distance per motor rotation" that is set in the Scaling menu of the axis ? I am working on my own homing function block for sensorless (hardstop) homing and I want to make it be universal between different axes with different motor's scaling for distance per rev so I need to know this value from the axis itself. I know I could do it by just creating an input variable for the function block but I'm leaving that option as a last resort.
Last updated: 2025-06-12

Post by callumo1 on Check For Open Dialogs On Client ^{CODESYS Forge talk (Post)}
Is it possible to make a function that checks to see if there are any open dialogs on a given clients. I think VisuDialogs.VisuDlgUtil_IsDialogOpen does this for a given dialog name, but is it possible to do this for any dialog. Appretiate any help Cheers Callum
Last updated: 2023-09-25

Post by callumo1 on Check For Open Dialogs On Client ^{CODESYS Forge talk (Post)}
Thanks for the reply. I want to be able to check if any dialogs are open of any name. I already have a function similar to what you have send but I don't want to have to run it for all the different dialog names. Thanks
Last updated: 2023-09-26

Post by tk096 on Motion FB Error ^{CODESYS Forge talk (Post)}
Hi, Softmotion Robotics does not support tracking in/out to dynamic coordinate systems with relative movements. Is MC_MoveLinearAbsolute an option? See SMC_RELATIVE_MOVEMENT_TRACKING_CS in https://content.helpme-codesys.com/en/libs/SM3_Error/Current/SM3_Error/SMC_ERROR.html Concerning the other error: Do you use any motion function blocks of SM3_Basic to move a single axis of the robot in your application?
Last updated: 2023-10-20

Post by leon78 on Codesys 3.5 SP17 Patch 2 CheckBounds (POUs for Implicit Checks) ^{CODESYS Forge talk (Post)}
Hello! I use CheckBounds (POUs for Implicit Checks). But I have a problem. I use an array as an VAR_IN_OUT of Function Block. If I try to monitor the array of variable length ([* ]), its does't work. The CheckBounds POU isn't called. If I use the array of fixed lenght ([lower..upper]), the CheckBounds POU is called. Why?
Last updated: 2023-11-14

Post by leon78 on Codesys 3.5 SP17 Patch 2 CheckBounds (POUs for Implicit Checks) ^{CODESYS Forge talk (Post)}
Hello! I use CheckBounds (POUs for Implicit Checks). But I have a problem. I use an array as an VAR_IN_OUT of Function Block. If I try to monitor the array of variable length ([* ]), its does't work. The CheckBounds POU isn't called. If I use the array of fixed lenght ([lower..upper]), the CheckBounds POU is called. Why?
Last updated: 2023-11-14

Post by nz-dave on Bool turning on in case stament in wrong state? ^{CODESYS Forge talk (Post)}
pretty sure its not. ive done a cross reference and only have one write that sets it to true. Only way i can stop it is to remove the function block call from the main pou that is running said case. its got me stumped:/
Last updated: 2023-12-16

Post by tvm on Function block method default arguments ^{CODESYS Forge talk (Post)}
This works for me in Schneider Machine Expert 2.2, which is based on Codesys 3.5.19. It did not work in Machine Expert 2.1, which was based on Codesys 3.5.16. METHOD PUBLIC Method1 : INT VAR_INPUT TestVar: INT:= 5; END_VAR Method1:= TestVar; PROGRAM SR_Main VAR TestFB: TEST_FB; Var1: INT; END_VAR Var1:= TestFB.Method1();
Last updated: 2024-01-04

Post by aniket-b on How to protect library project? ^{CODESYS Forge talk (Post)}
I have library projects which has few function blocks. I have assigned security to each FB. I want to protect them and user can only be able to use it without viewing the code inside. What kind of file I should send to user? Is it compiled library file?
Last updated: 2024-01-22

Post by nano on Modbus TCP/IP slave communication errow ^{CODESYS Forge talk (Post)}
please tell us the exact error message from diagnostic. U can view it at devicetree in the node-element diagnostic from modbus-configuration. u also can activate the function auto-reconnect in master and increase a little bit the timeout and the repetition to male thw communication a little bit more robust
Last updated: 2024-02-04

Post by evanclegg on Digital Clock ^{CODESYS Forge talk (Post)}
To display the current time, you’ll need to retrieve it from the system clock. In CODESYS, you can use the built-in function SysTime to get the current system time. Here’s an example of how you can use it: VAR dtCurrentTime: DATE_AND_TIME; sTime: STRING(8); END_VAR dtCurrentTime := SysTime(); sTime := TIME_TO_STRING(dtCurrentTime.t); The sTime variable now contains the current time in the format “HH:MM:SSuno online".
Last updated: 2024-02-28

Post by markushunter on Different behavior between the "Start" button in the IDE and the Cmp function "AppStartApplication()" ^{CODESYS Forge talk (Post)}
One workaround is to create a second application which is started after the rested of the main application. The second application starts the main application after time x and is rest after done start of the main application. No problems during the fieldbus re-start by this workaround.
Last updated: 2024-03-22

Post by nano on Error building Extension SDK Linux code ^{CODESYS Forge talk (Post)}
Hey schnepper, when i look into your c-file, i would say that only the main-function is declared with cext-addendum in your codesys-library-project. all yöur funtions in library has to be the cext-addendum when the external implementation is activ. if i remeber right, methods and other subelements dont need that, but every base-elements
Last updated: 2024-04-02

Post by hanoues on Holding brake release ^{CODESYS Forge talk (Post)}
I've tried using the SMC3_BrakeControl function block to control the brake, but unfortunately, it's not functioning as expected. Despite setting the appropriate parameters and inputs, the brake control does not operate correctly. Any insights or suggestions on resolving this issue would be greatly appreciated. STATE_MANUAL.UNLOCK_BRAKE: IF Button_release_brake THEN GVL.drum1_Control_Brake:=TRUE; FBA.T11_ContBrake.bExecute := TRUE; GVL.manual_state := STATE_MANUAL.WAIT_FOR_BRAKE_RELEASE; END_IF STATE_MANUAL.WAIT_FOR_BRAKE_RELEASE: IF FBA.T11_ContBrake.bDone THEN FBA.T11_ContBrake.bExecute := FALSE; GVL.manual_state := STATE_MANUAL.WAIT_START_BUTTON; END_IF
Last updated: 2024-04-08

Post by idir93dz on Identifier 'IoDrvGPIO' not defined ^{CODESYS Forge talk (Post)}
Hello, After installing the pi runtime and creating a pi project, I get these errors: [ERROR] Untitled3: Application [Device: PLC Logic]: C0046: Identifier 'IoDrvGPIO' not defined [ERROR] Untitled3: Application [Device: PLC Logic]: C0080: Function block 'IoDrvGPIO' must be instantiated to be accessed [ERROR] Untitled3: Application [Device: PLC Logic]: C0004: 'IoDrvGPIO' is no component of 'IoDrvGPIO'
Last updated: 2024-04-10

Post by k2saki on Automatic TOOL Length Measurement like Typical CNC Machine. ^{CODESYS Forge talk (Post)}
I'd like to measure tool length using SW. How do I set variable from the accurate drive position when switch turn ON/OFF? Hopefully, I'd like to measure Z-Pos with M-Function in G-Code automatically, And I'd like to set it to G43 as tool length correction.
Last updated: 2024-05-09

Post by andreag0 on How to access to variable value through symbolic string name ^{CODESYS Forge talk (Post)}
Hello, anyone know how to get valiable value using a symbolic string name? For example: - send string to runtime using TCP/IP contains "GVL.TestINT" and get back the value. I need function that will translate the string to symbolic variable. Thank you. Andrea
Last updated: 2024-06-13

Post by matt-purcell on Which Lib to use, connect to a socket with URL instead of IP address ^{CODESYS Forge talk (Post)}
I've been searching through these libraries, syssocket and net base services and they all seem to use the same structure for IP address for the connect function, SOCKADDRESS. At a glance, it doesn't look like that'll work, maybe it's just missing in the documentation somewhere?? I'm wondering if anyone has done it.
Last updated: 2024-06-17

Post by rikher on Error: Too few outputs exixts for the box 'MemCopy' (minimum is 1). ^{CODESYS Forge talk (Post)}
I am using MemCopy Function for this example: https://www.youtube.com/watch?v=DeTCT5Vyn28&t=482s It is from library WagoSysPlainMem. I want to use this for an MQTT example. However, Codesys is complaining the block does not have outputs. How to fix this?
Last updated: 2024-06-19

Post by jeffersonhui on SysProcessExecuteCommand2 terminate ^{CODESYS Forge talk (Post)}
Hi, I am using the SysProcessExecuteCommand2 function from the SysProcess library to run the candump command in the PLC's Linux environment. However, the candump command stays running indefinitely. If I was running the candump command from a terminal (via PuTTy, etc), that command usually requires Ctrl+C to terminate. Is there a way to terminate a command that is executed with SysProcessExecuteCommand2?
Last updated: 2024-06-24

Post by tk096 on Some 'pathetic' errors in SoftMotion program ^{CODESYS Forge talk (Post)}
Hi, I suppose that you are referring to the error code "SMC_FB_WASNT_CALLED_DURING_MOTION"? Starting of Softmotion version 4.15.0.0 the instance path of the function block that has not been called is logged into the device log. This might help you to identify why it has not been called.
Last updated: 2024-07-18

Post by timvh on Array to String ^{CODESYS Forge talk (Post)}
The string_Util_Intern is not the library I referred to. With a CONCAT function (also with the string util library) a search is done for the NULL character. If you concatenate 20000 characters to one string, then the longer the string, the longer it takes to find this NULL character.
Last updated: 2024-07-24

Post by tk096 on gear over gear (2 masters,1 slave) - how to do it? ^{CODESYS Forge talk (Post)}
Hi, you could calculate the position/dynamics of the slave axis yourself and use one of the function blocks SMC_FollowPosition/SMC_FollowSetValues to move the slave axis. https://content.helpme-codesys.com/en/libs/SM3_Basic/Current/SM3_Basic/POUs/Movement/Direct/SMC_FollowPosition.html https://content.helpme-codesys.com/en/libs/SM3_Basic/Current/SM3_Basic/POUs/Movement/Direct/SMC_FollowSetValues.html
Last updated: 2024-08-19

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