Post by timvh on OSCAT Scale_r function not working in LD 4.60 works in LAD2 on 3.5.21sp3 ^{CODESYS Forge talk (Post)}
It seems like a bug in FBD. Work-around: If you click on the small line between the box and the output variable and delete this, the variable is removed. When you then assign a variable again (Ctrl-A), then you will see that the line will be a bit longer. If you then select the previous variable, you will see that it works.
Last updated: 2025-10-26

Post by ph0010421 on Network variable stops sending ^{CODESYS Forge talk (Post)}
SP21...yes, Online change definitely causes a problem aswell.
Last updated: 2026-05-07

Post by mbmik on IoDrvModbusTCP_Diag not defined when using MODBUS ^{CODESYS Forge talk (Post)}
Hi Im trying to setup a Weidmüller WL2000 to run with MODBUS, to get some data from a server. Codesys V3.5 SP20. The issue is, that whenever i attach an ethernet port and add MODBUS Master und also a Slave, codesys will compile the project, but there always seem to be some remaining errors, which or only visible, when setting the messages window to "Pre-Compiled". I tried a lot of stuff to get rid of these errors, but cant find to seem the reason. New installation of codesys, cleaned project, setup completely empty new project, manually adding libs. Nothing helps. Any help is apreciated. Maybe we are doing something wrong.. Example Project is available, if somebodey wants to take a look. Greetings and thanks alot
Last updated: 2024-04-15

Post by kurt9 on ReadWriteEEprom FB question ^{CODESYS Forge talk (Post)}
I want to programmatically write the alias address to a new EtherCAT slave when I plug it into my IPC EtherCAT network. I am looking at the ReadWriteEEprom FB and see that one of the elements is "pbyData". which is the pointer to byte that is usually set to 2048 bytes. Since I am setting the alias address to the EEprom only (EEprom address 16#0012), I would assume that what I am writing is 2 bytes only. Does the pbyData have to be specified as ADR(myArray) where "myArray" is the 2 bytes of the alias address? How is the best way to set this element of the function block? Thanks in advance
Last updated: 2026-05-18

Post by ranadheer on Implementation of IEC-104 ^{CODESYS Forge talk (Post)}
Hi Everyone, As we didn't have client for IEC - 104 - only server server is available , so because of that we are trying to make establish the communication between the external simulator as a Client and codesys itself as a server. We are looking for the variable behavior from CODESYS has to change according to the message triggered by the CLIENT (we are using simulator Application like Redisant). We are able to see the log data as the status of triggering the SCS from Client received to the Log data of the codesys device(attached screen shot of it) and in simulator panel we had set the details to trigger the data from Redisant to Codesys. Current Status: The project builds and runs successfully, but I need guidance on how to connect this to an external IEC-104 simulator for testing and visualization by using demo mode.
Last updated: 2025-10-14

Post by pernockham on Trend legend naming and access/config to/of trend/legend-variables ^{CODESYS Forge talk (Post)}
Trying the web-version of trend-data. This seems to be a impressive tool, but I lack/cant find a number of what I would think are important parts. There does not seem to be a way to get away from the dot.notated variable naming in the legend.. A developer might want the dot-notation but an end-customer will surely not. For instance I want to display 12 temperatures, instead of t1, t2 etc.. they will be named. gvl_io.unit[1].trend.temps.t1_a gvl_io.unit[1].trend.temps.t1_b gvl_io.unit[1].trend.temps.t1_c gvl_io.unit[1].trend.temps.t2_a .. gvl_io.unit[1].trend.temps.t4_b.. gvl_io.unit[1].trend.temps.t4_c.. Quite a lot of unnecessary text/data taking space from the actual trend => Is there a way to access/interface the legend-data programmatically so I can change the presentation/naming?
Last updated: 2025-12-16

Post by danieldiaz on Problem with FB execution ^{CODESYS Forge talk (Post)}
Hello everyone, I've been working on a system which needs an error function, with this purpose I've created a FB programmed in LD, after debugging I run the simulation. It seems that the variable linked to a coil doesn't change the value when the contacts are associated to input variables. When I use internal variables the logic works properly. I don't know if the problem is related to the variables definition or with the logic program. As you can see in the image, I1 and I2 are variables declared on the FB, the rest are input variables. If I force the eStop and Reset signals to TRUE the coil value should change, but it doesn't. However in the second network if I1 is TRUE the coil change to TRUE as it has to be. To sum up, my doubt is why that coil doesn't change its value? I would like someone to shed a light on this. Thanks!
Last updated: 2024-04-02

Post by egau on Mutate Hash table value ^{CODESYS Forge talk (Post)}
Hi, using the ElementCollections Library, why isn't it possible to mutate a value found within a HashTable? From what I understand, the only way to change a value would be to use the RemoveByKey(), followed by AddKeyValuePair(). My goal is to use a Data Structure that works like a Dictionary in Python. The HashTable seems to come close to this, except that the values themselves seem to be immutable... In python, we can mutate a dict easily (see attached picture).
Last updated: 2024-08-29

Post by jvfred on Reading a negative number ^{CODESYS Forge talk (Post)}
I have a Codesys-based Eurotherm E+PLC400 connected to Codesys HMI SL for visualization. I am also bringing in several Pressure Indicators via the Ethernet. Everything works; however, the Pressure indicators sometimes read a negative value. When they do, the displayed value on the screen reads "65532." While I know what it represents, the customer freaks out and wants it to read "0" or a negative number. The value comes in as an integer, just in case that matters. Does anyone have any ideas?
Last updated: 2025-05-22

Post by syjoo on Recipe Manager in PRG (3.05.13.XX) ^{CODESYS Forge talk (Post)}
I'm using version 3.5.13. Is it possible to handle Recipe Manager in PRG in this environment? Can you give me a simple example? Although it has been confirmed that the functions work on Recipe Manager, they do not work properly when implemented through FB within a simple PRG. I would like to save the current value as a recipe or load the recipe's value as the current value. And I want to save the recipe as a file or load the recipe saved as a file. somebody help me. (TT)
Last updated: 2024-04-15

Post by r-niedermayer on Issue with WebVisu on Raspberry PI ^{CODESYS Forge talk (Post)}
Regarding to your application: When clicking in the web visualization, the boolean variable will be tapped for both buttons. The LED in the web visualization lights up as long as the variable is true The used variables should come from the GVL, ad/or thePLC_Prg. We see no difference or problem in both projects: You have created a visuelement Push button a a tapper, that is supposed to control the variable in this way as expected. This is also reflected (switching Bool from false to true) in the program code, as well as in the (GVL declared) variables. Wherever the misunderstanding comes from: no, this is not memory or license related. Our best guess: it is probably more of an applicative/conceptual implementation.
Last updated: 2024-04-11

Post by pernockham on Trend legend naming and access/config to/of trend/legend-variables ^{CODESYS Forge talk (Post)}
There seems to have been included an updated in the last release 4.9.0.0 or am I wrong (I think I tried out these settings previously without giving the result I wanted contrary to what I see today)? Now an empty check box for "display variable name" is effective, and will present the Variable with the "Description" instead. Perfect! Seems to be some minor formatting still that needs adjustment. See attached screenshot. The apostrophe "'" between "description" I suppose should not be there? Also I guess the same apostrophe (although not visibly shown) gives an extra space between the variable-description and the ":"?? Thanks!
Last updated: 2025-12-19

Post by leandroct on Error reading files after runtime update from 4.0.0.0 to 4.8.0.0 ^{CODESYS Forge talk (Post)}
Since version 19 they changed how file access is handle. There are two solutions: 1. You change where the file is stored (need to go to: /PlcLogic/) 2. You can, if you don´t want to store at PlcLogic, add the following line in the CODESYSControl.cfg under [SysFile]: ForceIecFilePath=0 The CodesysControl.cfg is at C:\ProgramData\CODESYS\CODESYSControlWinV3x64\xxPROJECT_NUMBERxx\ Here the email they sent me: "with the 3.5.19 Version we changed how files are handled. See following issue: CDS-81506 - CODESYS Control SysFile system file access vulnerability. There are two solutions: 1. You change where the file is stored (need to go to: /PlcLogic/) 2. You can, if you don´t want to store at PlcLogic, add the following line in the CODESYSControl.cfg under [SysFile]: ForceIecFilePath=0 Here is the official release-note: [[COMPATIBILITY_INFORMATION]] With the activation of ForceIecFilePath the file access from IEC is now restricted to the configured paths only (file sandbox)! [SysFile] ForceIecFilePath=1 (new default) The standard path is the current directory, the PlcLogic subfolder or a configured path. Every file access outside of this path is configured via PlaceholderFilePath, for example access to temporary files or removable media: [SysFile] PlaceholderFilePath.1=/tmp, $TMP$ PlaceholderFilePath.2=/media/usb, $USB$ PlaceholderFilePath.2.Volatile=1 For more information see our tutorial FilePath & Placeholders. To restore the old behavior ForceIecFilePath may be configured as follows: [SysFile] ForceIecFilePath=0 BUT WE HIGHLY RECOMMEND TO LEAVE THIS SETTING AT ITS NEW DEFAULT VALUE! "
Last updated: 2024-05-07

Post by thn-power on How to change OPC NodeId IdentifierType ^{CODESYS Forge talk (Post)}
Hi Yet another OPC UA question. When setting up a OPC server using "Communcation manager" (Symbol set and information model) in Codesys the NodeId is always given as "opaque" type. At least when browsing using UAExpert. Other standard OPC objects use numeric (or string) identifier, but for some reason my variables seems to get opaque/binary type. See attached photo. How can I change this? I can't see that this is a parameter in the CodesysControl.cfg. Can this be specified in the information model nodeset? And is it possible to specify the exact numeric or string NodeId for each instance? And on a related topic, is there a way to export the OPC server nodeId's with variable name so that it can be imported in a OPC Client? The .xml files in the project folder does not seem to contain the NodeId.
Last updated: 2024-09-20

Post by timvh on CPU + EtherCAT redundancy ^{CODESYS Forge talk (Post)}
It works well with two Wago 750-8210's. I helped a few customers setting this up. But it should work with any device which can control EtherCAT I/O, is real-time and has sufficient network interfaces. Two network adapters can be used to create a redundant EtherCAT network (you need 2 additional switches for this). The other network adapters can be used to interconnect the 2 PLC's (synchronization). We noticed that if you exchange variable lists that there could be some issues if you have long lists. So what we did is use a SoftPLC on a server that contains all the settings which continuously sends network packages (GVL sender) and which is received by both PLC's (network receiver). Switching over is done in milliseconds. The bus doesn't notice the change-over. EtherCAT communication works flawlessly.
Last updated: 2026-01-30

Post by george32 on CSV file and string manipulation. ^{CODESYS Forge talk (Post)}
Dear folks, I think I have a rather simple question but I could not find the right answer to my question: I have made with Excel a CSV file where I would like to have some general data regarding my program variables. I have made an program what let me read the file. The string I am currently get is at follows: 'IP_Adres;192.168.45.12$R$NPort_number;2000$R$NCycle_time;43$R$NStart_Standard_IO;20$R$N' Now I want to split the string in multiple part, which I later would connect to the right variable. By Google and experimenting I have reached to the following code for the first part of the splitting proces: // Splitting the BOM of the string: Received_string := FileReadString; IF LEFT(STR:=New_string,3)= '' THEN Received_string_without_BOM :=RIGHT(STR:= Received_string,SIZE:= (LEN(STR:= Received_string))-3); END_IF //Splitting the remaining string in part for later declaration. WHILE index = 0 DO index_split_part := FIND(STR1:= Received_string_without_BOM,STR2:= '$R$N'); Part_of_String[index]:=LEFT(STR:=Received_string_without_BOM, SIZE:= index_split_part); index := index + 1; END_WHILE However in the splitting proces I could not understand what is really happening. I understand that the Find() function returns the first value the $R$N in the Received_string_without_BOM. This would mean that the index_split_part := 23 I|P| _ |A |d|r|e|s|;|1_|9 |2 |. |1 |6 |8 |. |4 |5 |. |1 |2 |$ |R |$ |N |P | 1|2| 3 |4 |5|6|7|0|9|10|11|12|13|14|15|16|17|18|19|20|21|22|23|24|25|26|27| So the next part is to read the first 23 characters of the Received_string_without_BOM with the LEFT() function. I expected that the outcome the following was: 'IP_Adres;192.168.45.12$'. However the outcome is: 'IP_Adres;192.168.45.12$R'. I do not understand where the R after the $ sign comes from, because its place is 24 so it would not be added to the part_of the_string[index]. If I hard coded value 24 for the size it gives me the following return: 'IP_Adres;192.168.45.12$R$N'. I would expect everything till the R but the code adds the $N also to the string. I hope someone could explain to my what I am seeing wrong in my point of view? With kind regards, George
Last updated: 2024-09-27

Post by timvh on Modbus TCP & RTU with Control for Linux SL ^{CODESYS Forge talk (Post)}
RS485 doesn't seem very logical to use in VPLC's in my opinion. I also don't know if this is supported.... But for TCP/IP, I think you still need to configure the Nic settings. See the attached png. In my case enp6s0. When changing this setting, restart the VPLC. What is really nice, is that you don't have to configure the IP address setting in Linux. By setting the Nic to a certain IP address in the CODESYS instance configuration, this is automatically done for you. I only tested this with EtherCAT, but I guess this works the same for Modbus TCP/IP.
Last updated: 2024-10-23

Post by paulpotat on Exclude traces when searching with ctrl+F ^{CODESYS Forge talk (Post)}
Hello, I was wondering if there is a way in codesys to exclude the traces from the search when using the "ctrl+F" window ? That would be nice to improve the search functionnality when looking for a specific variable. Sometimes when I iterate through all occurences with the "find next" button, it opens the trace configuration window. I would expect to be able to close it and go to the next occurence with the "find next" button, but after closing the trace configuration window the search says it has reached the end of the scope (even if in reality there are other occurences of the variable elsewhere). I tried to enable / disable the "search up" checkbox but it's not changing anything. I hope somebody have insight on this, BR
Last updated: 2024-08-06

Post by mani-i4point0 on Issue with WebVisu on Raspberry PI ^{CODESYS Forge talk (Post)}
Hi, I am running Codesys Runtime by purchasing 'Codesys control for raspberry pi MC SL', I am trying to use the Variables from my GVL's. Few of the variables used as a Pushbutton form the Visualization. These 'BOOL' Variable getting unlatched automatically even though there is no write function in the Overall project. All of them are 'Read' functions, at the same time few other BOOL variable behaviors are seems to be fine. I have tried, clean all and download, serval time restarted the hardware. Happy to share any any information. Your input to resolve this issue would be highly appriciated. Version Details: codesyscontrol 4.8.0.0, armhf codesyscontrol based on SDK 3.5.19.0
Last updated: 2024-03-20

Post by akrawczyk on Dynamically enabling/disabling Modbus slave devices in runtime (performance issue with timeouts) ^{CODESYS Forge talk (Post)}
Hi everyone, I'm working on a CODESYS-based project running on a Weintek cMT2078X HMI with a built-in CODESYS runtime. The system communicates with multiple Modbus RTU slave devices, arranged in a cascade. The number of connected units can vary between 2 and 8, depending on the installation. Each slave has 17 Modbus channels, which are polled cyclically every 5 seconds. The issue is that when fewer devices are physically connected (e.g. only 3 out of 8), the Modbus master still attempts to communicate with all configured slaves. This leads to massive delays due to timeouts (currently 200ms per channel). For one disconnected device, that’s: 17 × 200ms = 3.4 seconds of delay per polling cycle, and this quickly multiplies with each additional missing slave. This behavior significantly degrades the system's performance and responsiveness. We attempted a workaround where we tried to trigger polling based on a variable in the PLC program, but this caused instability and even led to hardware hangs/freezes on the cMT2078X – likely due to clashes in how the Modbus polling engine and program logic interact at runtime. My main questions are: Is there a way in CODESYS to dynamically enable/disable Modbus slave devices at runtime, using a BOOL or INT variable (e.g. indicating number of active slaves)? Can devices or channels be conditionally polled or temporarily disabled without removing them from the device tree? Are there any best practices or examples for handling variable numbers of Modbus slaves in scalable systems like this? Would splitting communication across tasks or interfaces help reduce the impact of timeouts? Any advice, documentation references, or architectural suggestions would be extremely helpful. I'm looking for a robust way to dynamically scale slave polling without degrading system stability or performance. Thanks in advance!
Last updated: 2025-08-11

Post by dogulas on OPC UA C# client connecting to OPC UA CODESYS server ^{CODESYS Forge talk (Post)}
Ok, I have a simple test environment. From C#, using OPC UA, I can read DINTs, write DINTs, read Structs, but when I try to write a struct I get BadNotWritable. I am using Communication Manager, OPC UA Server, and IEC Symbol Publishing. I have a struct defined with one single DINT in it. The instance of the struct is in GVL. The struct is marked read/write in IEC Symbol Publishing. Any ideas? Pointers are welcome. public static async Task WriteStructA(byte[] structAData) { if (_session == null) throw new Exception("session is null"); // create a RequestHeader RequestHeader requestHeader = new RequestHeader { Timestamp = DateTime.UtcNow, TimeoutHint = 30000 // timeout in milliseconds }; // create an ExtensionObject to wrap the value to be written ExtensionObject extensionObject = new ExtensionObject( new ExpandedNodeId("GVL_StructA", 5), structAData ); // create a WriteValue object to hold the value to be written WriteValue writeValue = new WriteValue { NodeId = _structANodeId, AttributeId = Attributes.Value, Value = new DataValue(extensionObject) }; // put the WriteValue object into a WriteValueCollection object WriteValueCollection writeValueCollection = new WriteValueCollection() { writeValue }; // perform the write operation asynchronously WriteResponse writeResponse = await _session.WriteAsync( requestHeader, writeValueCollection, CancellationToken.None ); // check the result of the write operation if (writeResponse.Results[0] != StatusCodes.Good) throw new Exception("Write failed: " + writeResponse.Results[0]); }
Last updated: 2024-12-17

Post by k2saki on CNC / G01 Speed is very slow (or go-stop motion) in Continuous short segment . ^{CODESYS Forge talk (Post)}
I'm using CAD/CAM that outputs GCode with G01 many short segments from NURBS Curve, only X-Y axis. But CODESYS CNC motion seems much slower ( or stop-go motion ) in simulation mode than F-Value (I checked value from SMC_Interpolator - dVel ). In GCode G01, F value is F500, but movement is very slow, actual speed (dVel) is between 0 to 30 back and forth. I think very old CNC can move like that, but nowadays, a lot of CNC can move smoothly to process free curve ( somethimes option switch ) I tried to use G51 Dxx but I got the same result. My questions are 1) How do I improve CODESYS CNC motion in this case ? 2) How can I graph the sampling from dVel of SMC_Interpolate in CODESYS? From my GCode N2006 G01 X1.4364 Y-14.6847 F500 N2007 G01 X1.6759 Y-14.6768 N2008 G01 X1.9152 Y-14.6486 N2009 G01 X2.1547 Y-14.6400 N2010 G01 X2.3943 Y-14.6090 N2011 G01 X2.6336 Y-14.6002 N2012 G01 X2.8732 Y-14.5716 N2013 G01 X3.1127 Y-14.5634 N2014 G01 X3.3520 Y-14.5410 N2015 G01 X3.5915 Y-14.5336 N2016 G01 X3.8308 Y-14.5307 ... Thansk.
Last updated: 2024-04-29

Post by ewi04 on Recipe Manager - RecipeManCommands, load & write wrong values, Bug? ^{CODESYS Forge talk (Post)}
The individual structures were declared in a separate global variable list on a trial basis. But even this did not change the behavior. A total of 1667 variables are processed in a recipe. A reduction (e.g. saving only the first three drive parameter sets) also brought no change.
Last updated: 2023-11-15

Post by schorge on Modbus RTU Slave ^{CODESYS Forge talk (Post)}
Ich würde gerne bestimmt Modbus RTU Slave Adressen auslesen, leider bekomme ich keine Werte vom Bus. Verbindung erfolgt über einen Raspberry mit Modbus RS485 Adapter, welcher erfolgreich verbunden ist. Mit einem IOBroker kann ich die Daten erfolgreich auslesen. In der Modbus_COM_Port => Modbus_Serial_Device habe ich Input Register 4000 %QW und Startadressen auf Input Register 3000, als Variable ein Array[0..2999] of Word, kann aber keine Werte auslesen.
Last updated: 2023-12-06

Post by dkugler on Converting hex bytes to float ^{CODESYS Forge talk (Post)}
have a look at UNIONs. With a union you are able to write single bytes to the same adress area which belongs to a float variable at the same time. I like to do a lot of convertions belonging to interfaces and fieldbus in this way, f.eg. word / byte swapping etc.
Last updated: 2024-08-06

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