Post by mubeta on Strange problem with the ‘MC_SetPosition’ function
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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 tvm on multiply gives negatives
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It's probably because you have an INT in the input to the MUL function, which will then try to output an INT as well. INT variables can only handle values of -32768 to 32767. Your value of 523000 won't fit in an INT, so it turns into an invalid number. Use a DINT. This is usually better for working with time values anyway, because time values are all 32 bit. Or if you can't, use INT_TO_DINT(gvlp.detectie_nalooptijd_s) in the input to the MUL function.
Last updated: 2024-01-04
Post by matt-s on HMI Pushbutton/Move Instruction
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I have not gotten to the bottom of this yet no. I have double check that the variables are correct linked. When online with the program I can see the button and rung going true for the move instruction, yet it does not change. Forcing the bit in the program does change the value in Groov View. I am kind of at a loss here, especially since the other POU(For the pumps) does the same thing fine.
Last updated: 2024-02-02
Post by alez on CANOpen SDO to write VISIBLE STRING
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Hello, I am experiencing difficulties in configuring a CANopen device by sending SDOs. In particular I am attempting to write an Object Dictionary that has VISIBLE STRING as the Data Type. When I try to configure the sending of an SDO from Codesys to configure this parameter I am not allowed to enter a string value. In my particular case I am trying to change the Manufacturer Device Name ( Index 0x1008 ). Could it be that Codesys doesn't manage these types of variables?
Last updated: 2024-04-29
Post by ndzied2 on Rounding error in simple addition
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This is a consequence of how computers store floating point numbers. 0.1 cannot be exactly represented in a computer. This is not a CoDeSys thing. Here is a link to a converter to show you the exact value that is represented when you use a REAL data type (which is a 32 bit float). https://baseconvert.com/ieee-754-floating-point If you really need to keep track of 0.1 increments. use INT OR DINT and then add 1 each time and assume that there is one decimal place.
Last updated: 2024-05-24
Post by hhermsen on Codesys v3.5.22.10 - Internal error:System.AggregateException...Value cannot be null...Parameter name: expLValue
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I pinpointed down 4 possible causes for this compiler error: Bare/empty statements (;) standing alone inside an IF/CASE branch — just removed two instances. The optimizer that tries to inline/replace expression statements may choke when a statement has no actual assignment to extract. A VAR_IN_OUT parameter used directly as a FOR loop's own control variable (FOR X := X TO Y DO) General deep-nesting complexity — every one of my decode routines has the same shape (IF busy THEN ... FOR loop containing nested CASE/IF chains ... END_IF), and the crash trace consistently shows for loop → sequence → ifst → sequence → ifst → sequence regardless of the code change. This raises the possibility that it's not one specific statement but a structural depth/complexity limit in SP22.x's compiler optimizer — which would mean no small code change fixes the issue. Only restructuring to reduce nesting depth, or downgrading the compiler will. Something entirely outside my library files — which cannot not ruled out since the exact stack trace was triggered by a Visualization object, in a totally different codebase. This means the same crash signature can come from unrelated causes. IMHO cause 3 seems the most probable one..
Last updated: 2026-07-11
Post by mawaloc on IMAGE DISPLAY ACCORDING TO INPUT VARIABLE
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Hello thank you to all, it's work regards
Last updated: 2023-08-17
Post by totorovic on Pointer to Softmotion axis
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I get the same warning message with initialized variable. Codesys 3.5.19.20
Last updated: 2023-11-09
Post by timvh on OSCAT Scale_r function not working in LD 4.60 works in LAD2 on 3.5.21sp3
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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
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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
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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
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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
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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
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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
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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 r-niedermayer on Issue with WebVisu on Raspberry PI
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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
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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 egau on Mutate Hash table value
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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
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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)
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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 leandroct on Error reading files after runtime update from 4.0.0.0 to 4.8.0.0
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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
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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
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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.
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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
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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
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