Post by kporter on SoftMotion, accessing PDO input data via object ref/pointer ^{CODESYS Forge talk (Post)}
It looks like one can use the OutputData and InputData members of ETCSlaveStack: https://content.helpme-codesys.com/en/libs/EtherCATStack/4.2.0.0/EtherCATStack/ETCSlaveStack.html
Last updated: 2025-10-29

Post by ranadheer on conformation about the CODESYS Extends SL and CODESYS SDK ^{CODESYS Forge talk (Post)}
hello everyone would anyone here respond, Is CODESYS Extends SL and CODESYS SDK are same. If both are not same could you please give related data about this. Best Regards Ranadheer
Last updated: 2025-11-10

Post by unusual-data on C0138: No matching 'FB_Init' method found for instantiation of VisuClientObjectMgr ^{CODESYS Forge talk (Post)}
you can try to disable "Visualization Manager - Settings - Support client animations and overlay of native elements " selection" It worked for me, thank you.
Last updated: 2025-12-18

Post by tjacks on Opc UA Data Source Client Browse Error in Codesys HMI ^{CODESYS Forge talk (Post)}
Codesys V3.5 SP21 Patch 3 Codesys HMI 3.5.21.30 I'm trying to connect to an OPC UA server on a Kuka robot controller using Codesys HMI's data source manager. I get through the login phase and the client browses most of the data structure on the server but errors out toward the end with a generic: Error while browsing the client, Failed with service result: BadUnexpectedError. If I complete the data source setup and try to update variables, I get the attached stack trace for the error. I've tried several different endpoint and security options. Most get me through the login but all error out while browsing. UA Expert happily connects and browses with the same configuration. I've connected this same version of Codesys to TwinCAT OPC UA servers and Siemens PLC OPC UA servers. Any ideas on what may be causing the generic BadUnexpectedError during OPC UA server browse?
Last updated: 2025-11-17

Post by ketanvaishnav on Redundancy Codesys Runtime, Synchronization ^{CODESYS Forge talk (Post)}
i am facing same data sync issue. i am use two 750-8212 (FW30) controllers. datas are sync from active to standby during changeover time, but datas are not sync from standby to active.
Last updated: 3 days ago

Post by thysonfury on OPTO22 Groov Epic PR2 Modbus Comms Dropping out every 2 hours and 4 Mins ^{CODESYS Forge talk (Post)}
Hi after some assistance with an error on a Groov PR2 PLC. We have a few different communications set up as shown below: One Modbus TCP Slave Connection - ( Sending / Receiving Data from a PC ) Two Modbus TCP Master Connection - ( Reading Data from a UPS Panel and Reading Data Gas Chromatograph) One Modbus RTU Slave Connection 485 - (Reading Data from a fire and gas panel) One Modbus RTU Master Connection 485 - (Sending Data to a Telemetry Unit) All Licenses have been installed as per OPTO22 suggestions of the order below: Modbus TCP Master Modbus TCP Slave Modbus RTU Master Modbus RTU Slave When I check on License manager the RTU Master license seems to disappear on installing the RTU. (What ever reason I’ve been told this is “normal”). If I use Device License Read It will successfully read all the licenses correctly. Now the issue is every 2 hours and between 4. For what ever reason the communications seems to end and lock up for about 20 seconds. During this time even if I was logged into the PLC it would kick me off and I’d have to re type the password to enter. Most of the devices can handle this however the RTU flags up a communications failure at the SCADA and is raising alarms every 2 hours and 4 mins. We’ve had multiple people go through the code to check for anything obvious. Does anyone have any ideas?
Last updated: 2024-04-15

Post by thysonfury on OPTO22 Groov Epic PR2 Modbus Comms Dropping out every 2 hours and 4 Mins ^{CODESYS Forge talk (Post)}
Hi after some assistance with an error on a Groov PR2 PLC. We have a few different communications set up as shown below: One Modbus TCP Slave Connection - ( Sending / Receiving Data from a PC ) Two Modbus TCP Master Connection - ( Reading Data from a UPS Panel and Reading Data Gas Chromatograph) One Modbus RTU Slave Connection 485 - (Reading Data from a fire and gas panel) One Modbus RTU Master Connection 485 - (Sending Data to a Telemetry Unit) All Licenses have been installed as per OPTO22 suggestions of the order below: Modbus TCP Master Modbus TCP Slave Modbus RTU Master Modbus RTU Slave When I check on License manager the RTU Master license seems to disappear on installing the RTU. (What ever reason I’ve been told this is “normal”). If I use Device License Read It will successfully read all the licenses correctly. Now the issue is every 2 hours and between 4. For what ever reason the communications seems to end and lock up for about 20 seconds. During this time even if I was logged into the PLC it would kick me off and I’d have to re type the password to enter. Most of the devices can handle this however the RTU flags up a communications failure at the SCADA and is raising alarms every 2 hours and 4 mins. We’ve had multiple people go through the code to check for anything obvious. Does anyone have any ideas?
Last updated: 2024-04-15

Post by thysonfury on OPTO22 Groov Epic PR2 Modbus Comms Dropping out every 2 hours and 4 Mins ^{CODESYS Forge talk (Post)}
Hi after some assistance with an error on a Groov PR2 PLC. We have a few different communications set up as shown below: One Modbus TCP Slave Connection - ( Sending / Receiving Data from a PC ) Two Modbus TCP Master Connection - ( Reading Data from a UPS Panel and Reading Data Gas Chromatograph) One Modbus RTU Slave Connection 485 - (Reading Data from a fire and gas panel) One Modbus RTU Master Connection 485 - (Sending Data to a Telemetry Unit) All Licenses have been installed as per OPTO22 suggestions of the order below: Modbus TCP Master Modbus TCP Slave Modbus RTU Master Modbus RTU Slave When I check on License manager the RTU Master license seems to disappear on installing the RTU. (What ever reason I’ve been told this is “normal”). If I use Device License Read It will successfully read all the licenses correctly. Now the issue is every 2 hours and between 4. For what ever reason the communications seems to end and lock up for about 20 seconds. During this time even if I was logged into the PLC it would kick me off and I’d have to re type the password to enter. Most of the devices can handle this however the RTU flags up a communications failure at the SCADA and is raising alarms every 2 hours and 4 mins. We’ve had multiple people go through the code to check for anything obvious. Does anyone have any ideas?
Last updated: 2024-04-15

Post by ewi04 on Recipe Manager - RecipeManCommands, load & write wrong values, Bug? ^{CODESYS Forge talk (Post)}
I'm getting closer to the error. The combination of STRUCT and ARRAY probably causes the strange behavior. As soon as the ARRAY is followed by a variable, the problem arises. Examples: X: ARRAY[1..2] OF INT; // okay Y: ARRAY[1..2] OF STRUCT; // problem Z: STRUCT; Z.ArrayOfInt[1]; // okay Z.ArrayOfStruct[1].Variable // problem // *update - array of array also causes the error A: ARRAY[1..2] OF ARRAY[1..4] OF BOOL; // problem I can't be the only one who has this problem. Or? Maybe there is a solution. Anyone? Or is it a bug after all?
Last updated: 2023-11-17

Post by alimans on OPC-UA Server, Symbol Set: Raise an error: Object reference not set to an instance of an object. ^{CODESYS Forge talk (Post)}
Hi everyone, I just created a very simple library without any code and, added it to my very simple project. after adding this library, I get an error when I try to open "Symbol Set" in "OPC UA Server" in "Communication Manager". Here is the code of my POU in the library: FUNCTION_BLOCK POU VAR eCommand : (CMD_NONE:=0, CMD_RESET:=-1) INT := CMD_NONE; END_VAR Attached is the error that I get. I also noticed that by removing the enumeration variable above (eCommand), I can open the "Symbol Set" again. Anybody has any idea why this error is raised and how could I use enumeration variables without error in "OPC UA Symbol Set"?
Last updated: 2024-08-08

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 rafa on MODBUS TCP SERVER DON'T AUTOMATIC STARTUP ^{CODESYS Forge talk (Post)}
Dear all, I have a project where I have two ModbusTCP communication drivers in the application. It's working normally until a power outage or the installation panel is restarted. As soon as the PLC CPU is restarted, the Ethernet port is OK, but the TCP Server displays an "UNDEFINED" error. I can't reset the error using the diagnostic confirmation or the "mbserver.xConfirmError" bit. I noticed that the error only appears in the "mbserver.byModbusError" memory and the description is "UNDEFINED." The "mbserver.xError" memory doesn't flag an error. When using the warm restart function and then START CPU, the devices return to normal operation. The following demonstration images; The main question is: How can I make devices boot automatically? Um using Codesys Version 3.5.20.30 Patch 3+ My CPU is a Weintek Cmtx Built-int - ( CMT3092x )
Last updated: 2025-07-15

Post by alexgooi on Modbus writing on value change ^{CODESYS Forge talk (Post)}
The way I usally tackle this is by syncing only words (then you are able to use the FB above). If you then want to write a Boolean simply type it like this. Value[1].0 := Bool1; Value[1].1 := Bool2; Value[1].2 := Bool3; Uints have the same number of bits than a INT/WORD so these ones will work as well (they are only represented diffrently). A Real will work but you will loose some infomration in the conversion. If you want to keep the information you can convert 2 words to a float with a function (for example with the IEEE-754 standard) . In this way the syncing to the server is very simple and in the Codesys Program you decide what part of the word you want to use.
Last updated: 2024-04-03

Post by davidbo on RETAIN PERSISTENT only stored at gracefully shutdown? ^{CODESYS Forge talk (Post)}
I have {attribute 'checksumnoinit_override' := '2629838988'} {attribute 'init_related_code' := '5c6efcf8-e0f4-4166-a9fa-17eadd8908df'} VAR_GLOBAL RETAIN PERSISTENT {attribute 'order_in_persistent_editor' := '0'} segmentValue: ARRAY[0..49] OF REAL; {attribute 'order_in_persistent_editor' := '1'} segmentTime: ARRAY[0..49] OF REAL; // Generated instance path of persistent variable PRG.test: INT; // Generated instance path of persistent variable PRG.nw_storage: SysSocket_Implementation.SysSocket_Interfaces.SOCK_ADAPTER_INFORMATION2; END_VAR When I have changed PRG.nw_storage it will not be stored at a power off, but if I do a: sudo systemctl restart codesycontrol and then a power off it will be stored. Is there a way to store persistent variables without a restart of codesyscontrol? Can anyone explain how and when CODESYS store persistent variables?
Last updated: 2025-11-17

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 janderson on OPC UA Server limitations, large array crashes runtime ^{CODESYS Forge talk (Post)}
What are the limitations of the OPC UA Server? I am trying to get data off my PLC that is acquired at high rates (~50k samples/s) so I am storing them in arrays and trying to get the arrays off the PLC. When I attempt to read a ~200k element array through OPC UA the server and runtime crashes (requiring tools -> update linux arm64 -> start runtime). Is there a better way to get highspeed data off? The ACDatalog library seems a bit irritating to use so I would prefer to go through OPC UA.
Last updated: 2023-08-23

Post by peterned on Programatically restart Codesys OPC UA server? ^{CODESYS Forge talk (Post)}
Hi, I'm using a Festo Codesys PLC (CPX-CEC-C1-V3), which is connected to a HMI panel. Both exchange data via OPC UA. Occasionally, the HMI stops displaying data, and looks as if there is no connection. If the HMI stops, the only way to make it work again is to restart the PLC. Restarting HMI has no effect. When the PLC is restarted, HMI starts working normally again. Is it possible to restart the OPC UA server from PLC code? I hope this will make fixing the HMI possible without a PLC restart. Thanks
Last updated: 2024-07-19

Post by peterned on Array to String ^{CODESYS Forge talk (Post)}
max. string length in Codesys is 255 chars. It's not possible to cram 20,000 things in a string. If you need to send the data to another device, send the whole data[] array (as byte array, without doing anything to it) and extract the information on the other end. As each struct member has a fixed size (81 bytes, as per you declaration), this will be easy. To save some resources, consider declaring string lengths - e.g. if the max possible length for key is 10 chars, declare it key: STRING(10); and it will occupy 11 bytes instead of 81
Last updated: 2024-07-20

Post by dawidr on Best practices for querying multiple MODBUS devices ^{CODESYS Forge talk (Post)}
Hi! What are the best practices for querying multiple Modbus devices? Single PRG or maybe multiple PRG (so basically multiple thread) per each Modbus device. In my current implementation I'm using single PRG and I'm utilizing FbMbMasterMultiQuerySerial and WagoAppPlcModbus.FbDigitalTwinMbSlaveDevice in eCockpit with PFC200. I've the timer with 2 seconds delay there and it was working fine for single device. But now I have three Modbus devices and for two of them I need to run 2/3 queries to get data from all registers. I noticed that the delays for getting the data from the Modbus devices is much bigger right now.
Last updated: 2024-07-31

Post by expertplas on No connection to opc server from codesys opc client ^{CODESYS Forge talk (Post)}
Hello, we have aproblen to connect our CODESYS OPC Client to the OPC Server. We installed the client according the CODESYS manual. We can browse the server and variables can be linked to the PLC. I created a self signed certificate for the CmpOPCUAClent as described. The server has a cerificate also. I copied the certificates to the trusted zone of server and client. But when it comes to data exchange we get an error message. "Communication error in data source OPC UA Library. Error ID : 7001 German : "Kommunikatinsfehler inder Datenquelle OPC UA -Bibiothek. Es wurde kein genauer Fehler angegeben. Fehler ID : 7001" It semms that there is no cerificate exchange. We are working with CODESYS 3.5 SP19 Patch 5. Can anyone here say something about this error or has an idea for a solution? Thanks.
Last updated: 2024-08-19

Post by trent on Automation server - trends stop recording - need to manually reconnect ^{CODESYS Forge talk (Post)}
Hi All, I use the analysis page in automation server to capture historical trends from my PLC - i only sample one point per hour but it does the job (for now) One issue I have is I often log on to analysis page to find the system has stopped recording trends from my PLC. To fix this, I need to choose "state information" in the "List view" under PLC and click "Reconnect" When I do this I see my variables listed under "parameters" under "PLC Details" start updating again and the trend in Data analyzer continues to update. My Question, Why do I need to manually reconnect? Is there a way to get automation server to automatically reconnect to the PLC so I continue to capture data from the PLC? Regards, Trent
Last updated: 2024-10-22

Post by struccc on HTML5 Controls - string(>80) values ^{CODESYS Forge talk (Post)}
Dear all, does anyone have experience with HTML5 controls recently? CODESYS 3.5.20.30 / Visualization 4.6.0.0 I'd like to create a simple lightweight text editor, with proper multiline handling, cut & paste, scrolling, etc. And it seems to work fine, just have problems with strings longer than 80 bytes.... Declaring a variable sText1 : STRING(8000) and referencing it in the HTML5 Controls corresponding value property works perfectly one way: the code receive the data as a string (See log1)... (Note TypeID 1000...) Also sending back the data (seems to work (See log2) except it doesn't change the value of the bound variable. Probably the issue is with using SendSimpleValue method... Naturally, I could do a workaround, but maybe there is a more standard way to implement this... Please let me know if you have any suggestions.
Last updated: 2024-10-23

Post by clarenced on Multiple applications on one device sharing variables. ^{CODESYS Forge talk (Post)}
I got this working using OPC UA. In the logic application I just added a Symbol Configuration. In the HMI application I added a Data Sources Manager and OPC UA Data Source. The one thing I don't like is the way the tags end up being named in the HMI application. In the logic application I have a program named PLC_PRG. It has a variable named testDINT. In the logic application the name I get for this variable is DeviceSet.CODESYS_Control_Win_V3_x64.Resources.Logic.Programs.PLC_PRG.testDINT. This is very long and looks like it could change if I used this on a different device type. Any ideas how I could get this name shortened down to just PLC_PRG.testDINT like it is on the Logic application?
Last updated: 2025-03-06

Post by clarenced on Multiple applications on one device sharing variables. ^{CODESYS Forge talk (Post)}
I got this working using OPC UA. In the logic application I just added a Symbol Configuration. In the HMI application I added a Data Sources Manager and OPC UA Data Source. The one thing I don't like is the way the tags end up being named in the HMI application. In the logic application I have a program named PLC_PRG. It has a variable named testDINT. In the HMI application the name I get for this variable is DeviceSet.CODESYS_Control_Win_V3_x64.Resources.Logic.Programs.PLC_PRG.testDINT. This is very long and looks like it could change if I used this on a different device type. Any ideas how I could get this name shortened down to just PLC_PRG.testDINT like it is on the Logic application?
Last updated: 2025-03-06

Post by mehakfatima on Need Help Configuring Energy Analyzers via Modbus TCP & RTU (RS-485) in CODESYS 3.5 ^{CODESYS Forge talk (Post)}
Hello everyone, I am currently working on reading data from energy analyzers using Modbus TCP and RTU (RS-485). In my previous software, I used the following method to add slave devices (i have attached the image) and configure registers: Add the Modbus slave device. Configure the communication parameters (baud rate, parity, etc.). Define the registers and their addresses for data retrieval. Now, I am trying to achieve the same in CODESYS 3.5, but I am not sure how to configure the Modbus master, add slave devices, and set up the registers properly. If anyone has experience with Modbus TCP/RTU setup in CODESYS 3.5, I would really appreciate your guidance! A step-by-step explanation or any references/tutorials would be extremely helpful.
Last updated: 2025-03-13

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