Post by sandro66 on Application-based license Modbus Channels ^{CODESYS Forge talk (Post)}
Hi Gatto, Using version 3.5.21.xx, it is no longer possible to use Modbus function blocks (I make extensive use of these FBs.)as shown in the example. https://content.helpme-codesys.com/en/CODESYS%20Examples/_ex_modbus_example.html The compiler detects one Modbus instance for each instance of the communication FB block. The example program above, although simple, reports 8 Modbus instances when compiled with the latest version. Codesys Support says that you must use fieldbus I/O mapping, but this will result in the loss of the ability to programmatically modify communication parameters. Sandro
Last updated: 2025-09-04

Post by bmatlove on AXIS_REF_SM3 Error Codes? ^{CODESYS Forge talk (Post)}
I'm trying to firm up alarming of axis faults. Declutter the code and figure out what's what. Diving into it, I see the AXIS_REF_SM3 function block provides uiDriveInterfaceError and dwErrorId, but I can't find any significance of these further than Drive interface error number Parameter number: 1014 and Drive specific error identifier, parameter number: 1031, respectively. Is there some corresponding appendix I could use to decode these? Also, is there any relation to the Error ID (of type SMC_Error) of the MC POUs? MC_Jog, MC_Reset, MC_MoveRelative, etc? If so, are the above errors redundant? Thanks in advance.
Last updated: 2025-09-22

Post by gseidel on CNC - system goes to X=0 Y=0 before CNC file execution starts, how to avoid that? ^{CODESYS Forge talk (Post)}
Hi peterned, the start position given in the CNC properties is only used if you use the compile mode OutQueue. With compile mode SMC_CNC_REF, you need to provide the start position in the IEC application. The function block SMC_NCInterpreter has an input piStartPosition. You can initialize it with the output of the forward kinematic transormation FB for your machine. In your case probably SMC_TRAFOF_Gantry2. Best regards, Georg
Last updated: 2024-04-30

Post by corriibme on Setting array values with JSON Utilities SL ^{CODESYS Forge talk (Post)}
It turns out that you can build JSON structures without ever calling the JSONBuilder function block directly. Instead, create a pointer to JSON.JSONData and invoke the necessary methods on its dereference. The parent object has a parent index of -1 (and an index of 0). EVERY other item (including keys, values, empty arrays and sub-objects) created by the setX methods needs the index to increase by 1. Then use the JSONByteArrayWriter FB to generate your JSON string
Last updated: 2024-05-23

Post by plunje on Sensor not set ^{CODESYS Forge talk (Post)}
A got a larger project but this very small example makes it clear. I have a button, and after it's clicked a lamp should flip on and stays on, and when the mouse-button is released it should stay on. When I try that in the PLC_PRG it works, but when I change it to a function block (seet attched demo proj) it isn't. I'm fairly new to PLC programming but are very experienced C# engineer, but this goes above my head...
Last updated: 2024-05-26

Post by swe-hob on call of a method of a function block in another program ^{CODESYS Forge talk (Post)}
Hi, Let's assume following: PRG_1 fb_1 : fbExample1; fb_1.method_1 do something... PRG_2 fb_2 : fbExample2; fb_2.method_2 if xTest then PRG_1.fb_1.method_1(); end_if; Is there a reason why runtime hangs when I call the method_1 in PRG_1 from a method in PRG_2? Both programs run in the same task. No chance that any other program calls the method. What I practically do there is that in the program PRG_2 I add a structed object into a buffer. In PRG_1 I just process the items in the buffer.
Last updated: 2024-06-03

Post by swe-hob on call of a method of a function block in another program ^{CODESYS Forge talk (Post)}
Hi, Let's assume following: PRG_1 fb_1 : fbExample1; fb_1.method_1 do something... PRG_2 fb_2 : fbExample2; fb_2.method_2 if xTest then PRG_1.fb_1.method_1(); end_if; Is there a reason why runtime hangs when I call the method_1 in PRG_1 from a method in PRG_2? Both programs run in the same task. No chance that any other program calls the method. What I practically do there is that in the program PRG_2 I add a structed object into a buffer. In PRG_1 I just process the items in the buffer.
Last updated: 2024-06-03

Post by trusty-squire on Read "Homed" status from EtherCAT drive ^{CODESYS Forge talk (Post)}
Hi, Is there a way to read the homed status from the EtherCAT drive directly? I am currently flagging the homed status on the succesful completion of the MC_Home function block, but I have had false triggers where the drive didn't actually execute the homing procedure but the MC_Home FB is marked as complete without error. I looked at other MC/SMC function blocks but the closest I can find is the "Homing" bit from MC_ReadStatus FB, but this doesn't show if the drive is succesfully homed, only that it's homing. Any guidance is welcome. Thanks!
Last updated: 2025-01-07

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 jbcregen on Accessing parameters from a structure or function block with the web interface ^{CODESYS Forge talk (Post)}
I have a project with hundreds of OPC-UA variables available on the network. A lot of these variables are used actively in various scripts that run in background in the OS (Linux). I'm experimenting with Automation Server and I have a hard time understanding how the web interface populates its parameters list for a given PLC (<plc details="" parameters="" for="" plc="" 'xyz'="">).</plc> In this page, it looks like the only variables available are the ones that are of a "base" type : bool, TIME, String, INT, etc. All the variables that are nested into function blocks or structures are not available in the web interface, even if they are available to any OPC-UA client. Is this a limitation of the Automation Server or is there something that can be done in Codesys?
Last updated: 2025-12-01

Post by tk096 on High Cycle Times for SoftMotion_PlanningTask when using AxisGroup ^{CODESYS Forge talk (Post)}
Hi, under this circumstances the performance of a Raspberry Pi 4 should be sufficient to run a Softmotion robotics application. A closer look at the project would be required. Maybe you could contact the codesys support? Usually it is recommended to run the planning task cyclically every 2ms with task priority of 0 on a dedicated core. In the task configuration you can have a look at the average and maximum execution time of the planning task. You could use the function block SMC_TuneCPKernel (https://content.helpme-codesys.com/en/libs/SM3_Robotics/Current/SM3_Robotics/POUs/AdministrativeConfiguration/Computation/SMC_TuneCPKernel.html) to define suitable values for the parameters 'fSyncBufferDuration' and 'fPlanningInterval'. However, as previously mentioned, the performance of a Raspberry Pi 4 with realtime patch should be sufficient. The 'fPlanningInterval' parameter specifies the maximum planning step width in seconds. The cycle time of the planning task should not permanently exceed this value. A higher value reduces the computational effort, but can lead to a violation or no full utilization of the set limit values for velocity, acceleration and jerk. From a starting value of 0.016 seconds, the value should be increased gradually until the performance is acceptable. The parameter 'fSyncBufferDuration' specifies the size (in seconds) of the buffer between the planning and fieldbus task. The cycle time of the planning task must not exceed this value at peak times (this will lead to the error SMC_CP_QUEUE_UNDERRUN). A higher value can compensate for peaks in the cycle time of the planning task. At the same time, however, this also increases the latency for executing interrupts and aborting movements.
Last updated: 2024-03-22

Post by fefefede on Get the numer of day ^{CODESYS Forge talk (Post)}
Hello i tro to create a program to turn on or off the air condition in relationship temperature and numer of day. I can't get the number of day. I try this after installing SysTime library but this not work and have this error on debug ------ Build started: Application: Device.Sim.Device.Application ------- Typify code... Generate code... [ERROR] giorno_accensione_aria: PLC_PRG Device: PLC Logic: Application: C0032: Cannot convert type 'Unknown type: 'SysTimeCore(TRUE)'' to type 'TIME' [ERROR] giorno_accensione_aria: PLC_PRG Device: PLC Logic: Application: C0035: Program name, function or function block instance expected instead of 'SysTimeCore' [ERROR] giorno_accensione_aria: PLC_PRG Device: PLC Logic: Application: C0032: Cannot convert type 'Unknown type: 'DayOfWeek(CurrentTime)'' to type 'INT' [ERROR] giorno_accensione_aria: PLC_PRG Device: PLC Logic: Application: C0035: Program name, function or function block instance expected instead of 'DayOfWeek' [INFORMATION] giorno_accensione_aria: PLC_PRG Device: PLC Logic: Application: C0181: Related position Build complete -- 4 errors, 0 warnings : No download possible PROGRAM PLC_PRG VAR Temperatura: UDINT; AriaCondizionata: BOOL := FALSE; CurrentDayOfWeek: INT; //Variabile Giorno CurrentTime: TIME; GiornoDellaSettimana: INT; DayOfWeek: INT; END_VAR CurrentTime := SysTimeCore(TRUE); // Ottieni l'ora corrente CurrentDayOfWeek := DayOfWeek(CurrentTime); CASE GiornoDellaSettimana OF 1: // Azioni per Lunedì 2: // Martedì se più 10° accend altrimenti spegni IF Temperatura >= 10 THEN AriaCondizionata := TRUE; ELSE AriaCondizionata := FALSE; END_IF 3: // Mercoledì se più di 50° accendi altrimenti spegni IF Temperatura >=50 THEN AriaCondizionata := TRUE; ELSE AriaCondizionata := FALSE; END_IF 4: // Giovedì se più di 40° accendi altrimenti spegni IF Temperatura >=40 THEN AriaCondizionata := TRUE; ELSE AriaCondizionata := FALSE; END_IF 5: // Venerdì se più di 50° accendi altrimenti spegni IF Temperatura >=50 THEN AriaCondizionata := TRUE; ELSE AriaCondizionata := FALSE; END_IF 6: // Sabato se più di 25° accendi altrimenti spegni IF Temperatura >=25 THEN AriaCondizionata := TRUE; ELSE AriaCondizionata := FALSE; END_IF 7: // Domenica sempre spenta AriaCondizionata := FALSE; END_CASE
Last updated: 2023-09-14

Post by opineiro on Stack overflow with really simple function ^{CODESYS Forge talk (Post)}
Hi, I have an issue with a function which sends a message through API Rest. I'm using a function from httpCLient library. I have tested this function inside a program and it works fine. But when I want to use it inside a function (so I can call it simultaneously from 2 different points on the main program) it gives a stack overflow error. In detail it says: "C0297 Stack Overflow on Main Task. Stack sizes... Call hierarchy:" I have simplified as much as I can the function, but I'm hitting a wall with this. Anybody has an idea of what's wrong? Thanks!
Last updated: 2024-09-16

Post by thecolonel26 on How to use FB_Init with nested Function Blocks? ^{CODESYS Forge talk (Post)}
Delete ME
Last updated: 2023-08-31

Post by mubeta on Strange problem with the ‘MC_SetPosition’ function ^{CODESYS Forge talk (Post)}
No errors in any condition. The function terminate correctly with the 'done' bit. Now I leave the machine and I don't know when I will be there again. The assumption you made I had considered. The operational limits of the axis are all fit for purpose, and this function should operate virtually without even noticing the motion limits. In fact in practice with the axis at low speed the function corrects any numerical value of the position in the range 0 ... 360° without any problem whatsoever in a single PLC scan cycle.
Last updated: 2025-01-10

Post by schnepper on Minor UI bug: cannot create SFC POU after creating a Function POU ^{CODESYS Forge talk (Post)}
After creating a Function POU, it is not possible to then create an SFC POU. Steps to recreate: * Create a new Function POU. SFC is not allowed for Functions, so SFC does not show in the Implementation language dropdown. * Click Add Object -> POU... Function is selected for Type. * Select Program * SFC is not present in the Implementation language dropdown
Last updated: 2024-05-23

Post by laazik2 on v3.5 SP19 - Modbus TCP Devices - Channel Limit? ^{CODESYS Forge talk (Post)}
I am actually wondering as well if there are plans to fix it or not? As adding two modbus devices creates it's own problems with connection limits and other issues, which some slave devices have.
Last updated: 2023-09-05

Post by danwoodlock on RPI Zero w - Edge gateway cant install ^{CODESYS Forge talk (Post)}
I believe the reason that I eventually lose my ability connect is because of exceeding the time limit for demo mode. Still unsure why I cannot update the edge gateway though.
Last updated: 2023-09-13

Post by lefish on Link to MCP23017 DevDescr and Lib dead ^{CODESYS Forge talk (Post)}
Hi everyone, Hi Mr. Schwellinger, the Link at the "inofficial device reporitory" from Mr. Schwellinger (https://forge.codesys.com/forge/talk/Runtime/thread/8981ce928a/?limit=25#e15f)to the MCP23017 Library and device.xml is dead unfortunately. Would someone please upload the files? Thanks alot! LeFish
Last updated: 2024-09-15

Post by eschwellinger on Link to MCP23017 DevDescr and Lib dead ^{CODESYS Forge talk (Post)}
Hi, it is important to click on 'more posts': https://forge.codesys.com/forge/talk/Runtime/thread/8981ce928a/?limit=25#e15f then scroll down until you are on MCP23017.
Last updated: 2024-09-16

Post by jacobwago on v3.5 SP19 - Modbus TCP Devices - Channel Limit? ^{CODESYS Forge talk (Post)}
Hello All, The solution is updating SP19 Modbus version from 4.3.0.0 to 4.4.0.0 (see attached image for bug fix). Thank you,
Last updated: 2024-09-30

Post by andrax on CodeSys Raspberry pi I2C driver not found ^{CODESYS Forge talk (Post)}
take a look here. there is a working driver in the collection https://forge.codesys.com/forge/talk/Deutsch/thread/87bfe42cbb/?limit=25#514f
Last updated: 2024-11-07

Post by cmason on v3.5 SP19 - Modbus TCP Devices - Channel Limit? ^{CODESYS Forge talk (Post)}
There still is no solution to this. I am running Modbus version 4.4.0.0 and it still wont let me add more than 10 channels. Does anyone have a solution for this?
Last updated: 2025-09-05

Post by cmason on v3.5 SP19 - Modbus TCP Devices - Channel Limit? ^{CODESYS Forge talk (Post)}
There still is no solution to this. I am running Modbus version 4.4.0.0 and it still wont let me add more than 10 channels. Does anyone have a solution for this?
Last updated: 2025-09-05

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