Post by tomast on WAGO 750-8212 nad Sinamics v20 modbus RTU speed control ^{CODESYS Forge talk (Post)}
Hi Guys, I am new to this forum and i would like to ask od anyone got communication with Siemens v20 vfd working via Modbus RTU? I followed many websites and finally got the communication working but have problema with read/write registers. For example if i try to read holding register 40011 which is accel time i get noth but when i set the offset 0x0000 en length 113 i get ale the registers. I cannot get speed control working. I read someth about stw (control Word) and hsw but have some problems to understand it en get it working. It would be really nice if someone could help me with it. Thx
Last updated: 2024-03-05

Post by jaspergain on Non-existing identifiers ^{CODESYS Forge talk (Post)}
Hello, I got a bit of a weird issue going on which is kind of annoying. So recently we switched a lot of Modbus IO to EtherCAT, as we were having issues with stability. All works fine, which is great. But sometimes when I change the program I get errors claiming that identifiers are not defined. Meaning I can't go online. See the picture below. I believe this is because some of these identifiers were used with Modbus, and they weren't properly removed/deleted? A clean all temporary fixes the issue, but it comes back again after a while of changing the code, and building. Any way to fix these non-existing required identifiers, or even find out where they are required? Thanks for the help in advance. Jasper.
Last updated: 2024-05-29

Post by gatto on Modbus tcp - channel ^{CODESYS Forge talk (Post)}
Hi can you give more details? Are you talking about a danfoss? wich model? Can post the configuration of channel' I used, on the past, serial modbus with danfoss fc280 I remember ((id x 10)-1) I remember that you couldn't use continuous reading/writing of the directors but you had to use them one at a time. it seemed that reading empty registers (caused by x10) was not accepted by danfoss. So I had created a scan that used just one register, then the next etc etc with a timed interval. But this was for the serial, I don't know if it's the same thing with ethernet. I currently use Ethernet TCP/IP interface with FC280.
Last updated: 2024-06-13

Post by husarz17 on How change Unity-ID in TCP Modbus Slave ^{CODESYS Forge talk (Post)}
My codesys is 3.5.21.30. I am using function ModbusServer from library ModbusTCP_Slave. The reason is that I need share 9000 Holding registers. By standard configuration it is only 4096. fbMbTcpDevice: ModbusTCP_Slave.ModbusServer; fbMbTcpDevice( wPort := 502, pInputData := ADR(awInputReg), pOutputData := ADR(awHoldingReg), uiInputDataSize := 10, uiOutputDataSize := 9000, xEnable := TRUE, tTimeout := 10000, InterfaceName := "eth0", xBusy => xBusy, xError => xError, byClientConnections => byConnections ); Ethernet port is cofigured: Network interface: eth0 IP address: 10.10.22.55 Subnet maskL 255.255.255.0 Default gateway: 0.0.0.0 And it only works when I am reading registers with ID 255 by Modbus Poll. Any other IDs don't work. The actual TCP client device try to read registers with ID 1 and I can't change it... Thanks in advance for your help!
Last updated: 2026-04-01

Post by dantheman on Connecting to SoftPLC Only Works By Turning Off Modbus Ethernet Port ^{CODESYS Forge talk (Post)}
I've also noticed that when I turn off "enp1s0", suddenly the source IP for the ModbusTCP changes to that of "enp2s0", which is what makes sense to me. When I turn it back on, the source IP remains that of "enp2s0".
Last updated: 2024-08-01

Post by rh-pk on v3.5 SP19 - Modbus TCP Devices - Channel Limit? ^{CODESYS Forge talk (Post)}
Hello jacobwago, I believe that the limit is fixed in the editor, but not in the driver package. There seems to be no link between the driver setting and the editor. Otherwise, I don't know why the input (>10) is blocked, but the function is available. Unfortunately, I cannot offer you any other solution apart from the one mentioned above. Kind regards
Last updated: 2024-09-30

Post by davidbo on Modbus: Is there a way to get the channel index from the channel name? ^{CODESYS Forge talk (Post)}
When I use the FUNCTION_BLOCK ModbusChannel I have to sepcify the integer iChannelIndex It can easily go wrong if one has many channels. It would be better if one could use the name. Is that possible? Attached a snippet of the channel name and the channel index to the left.
Last updated: 2024-10-21

Post by lsislsis on SIGABRT Error ^{CODESYS Forge talk (Post)}
After many tests i see that problem comes when serial communication established for modbus rtu. If the slave device not connected we don't see the exception. If the slave device connected at serial port then we have exception about 1 hour after startup and every 10 or 15 minutes. Any suggestion?
Last updated: 2024-11-08

Post by hagroth on v3.5 SP19 - Modbus TCP Devices - Channel Limit? ^{CODESYS Forge talk (Post)}
Today I was struggling with the same problem. in search for a solution i found this thread. Then i tried some things. It doesn't seem to be just a libraries' fault. In addition to 3.5.19, we also have a 3.5.18 version installed, the library versions of Modbus_TCP_Master and Modbus_TCP_Slave are the same, but more than 10 slave channels can be added in 3.5.18
Last updated: 2024-02-02

Post by jmauer on Codesys 3.5 SP16 Modbus change port settings. ^{CODESYS Forge talk (Post)}
Hello, I'm coming to you today because I'm trying to make the baudrate and the slave number dynamic. I've tried the "updateComPortSettings" method on the slave device but it doesn't work and gives the "Modbus_COM_Port" an error. Can you tell me how you got this method to work? Thanks in advance for your help jérémy
Last updated: 2024-02-20

Post by thewizard8 on Raspberry PI4 Serial Port ^{CODESYS Forge talk (Post)}
Hi All, I finally figured out how to solve it. The only away that I got it to work was to define parity to None on modbus configuration, and now works like a charm. Just for the record I'm using the GPIO port pins (8,10) and a RS485 to ttl shield that you can find online. Thanks all for the support! Regards Ricardo
Last updated: 2024-03-19

Post by cihangur on Application has invalid license metrics. ^{CODESYS Forge talk (Post)}
Hi, I have a "CODESYS Control Standard L" license and I use Ethercat and Profinet in my project. The project works seamlessly with two fieldbuses. However, when I add modbus_Com (Serial) or 1 OPC Tag to the project, the program throws an exception (Application app=Application has invalid license metrics!). My license should support 10*Modbus and 512 OPC Tags. Why might this problem occur?
Last updated: 2024-03-25

Post by rd76065 on Opto 22 Groov PR2 Modbus TCP Master communication ^{CODESYS Forge talk (Post)}
Previously, I have used ModbusEthernet_04 library for Wago for ModbusTCP Master communicational in Codesys V2.3. How to use same communication of similar UDT for Opto22 Groov PR2 PLC in Codesys V3.5 SP20. Can I use OSCAT library - Network -MB_Client or IODrvModbusTCP - ModbusRequest for this requirement? If any other please guide.
Last updated: 2024-05-31

Post by nulltrace on Modbus TCP Server connection is ESTABLISHED but all holding registers are value 0? ^{CODESYS Forge talk (Post)}
it works pretty well on codesys-version using device-tree and channels. heres the twist: each uid should be represented as a device, which in your case, it isn't. on the other hand, you found a solution which already works fine. Happy Modbus'ing
Last updated: 2026-04-09

Post by iliyatsukerman on SoftMotion auf PFC200 ^{CODESYS Forge talk (Post)}
Hallo, Wir würden Ihre Unterstützung bei der Überprüfung der Kompatibilität der folgenden Konfiguration sehr schätzen: • PSTR-LO-16/400FEV ELMO • SCALANCE XC208 • WAGO PFC200 750-8213/40-010 • Die SPS (WAGO) wird gleichzeitig eingesetzt als: o EtherCAT-Master zur Kommunikation mit einem Elmo-Servoantrieb (EtherCAT-Slave, 4 Achsen – generisches CiA 402-Profil), und o Modbus-TCP-Server zur Kommunikation mit einem Siemens Modbus-TCP-Client, welcher zur Fernsteuerung des Elmo-Servoantriebs über die SPS dient. Bitte bestätigen Sie, ob die SPS in der Lage ist, diese Dualfunktion — als EtherCAT-Master und gleichzeitig als Modbus-TCP-Server — ohne Konflikte oder Performanceprobleme zu unterstützen. Insbesondere interessiert uns, ob die CODESYS SoftMotion SL Basislizenz (2305000000-F) notwendig ist, um 4 Servoachsen zu steuern, und ob diese Lizenz auf einer WAGO PFC200 SPS mit CODESYS Version 3.5 Service Pack 19 Patch 40 oder höher unterstützt wird. Alle Achsen im Servoantrieb werden unabhängig voneinander gesteuert. Mit freundlichen Grüßen. ILIYA
Last updated: 2025-07-13

Post by mavitia on Application based license problem - Modbus TCP ^{CODESYS Forge talk (Post)}
I am running ubuntu on a raspberry pi, and installed an application based license Control Basic M on it, it runs a demo program fine, does not timeout etc. however, when I add a modbus TCP device, I start getting errors: <Entry severity="error" component="CmpApp" user="nobody" timestamp="12/18/2023 3:49:42 PM" infoId="24">Online change denied. Application Application is in exception state!</Entry> <Entry severity="error" component="CmpApp" user="nobody" timestamp="12/18/2023 3:49:42 PM" infoId="68">Download failed: Application=Application</Entry> <Entry severity="exception" component="CmpApp" user="nobody" timestamp="12/18/2023 3:49:41 PM" infoId="0">Application app=Application has invalid license metrics!</Entry> the modbus tcp slave runs, and the counter ticks up, however, when I call the variables on the %IX0.0 in my program, and try to upload the changes, I am getting the error messages which stop the program as far as I understand, the application based, M includes 2 fieldbus instances, but on the other side is fairly new, anything obvious I am missing out here?
Last updated: 2023-12-18

Post by tomast on Codesys and Siemens SINAMICS 20 modbus RTU "Response CRC Fail" ^{CODESYS Forge talk (Post)}
Hi everyone, I'm currently working on a project involving the control of 5 VFDs via Modbus RTU, this time using the WAGO 750-8212 CPU. So far, I've managed to make progress, but I've encountered an issue. While I can successfully read and write to all the registers I need, I consistently encounter a "Response CRC Fail" error when attempting to write the value 1151 to the STW register at address 40100. I'm able to set the frequency via register 40101 and adjust all other parameters using different registers. Setting STW to 1150 results in the drive ready boolean from the ZSW-bit being received instantly. However, the moment I attempt to send 1151 to register 40100, I immediately receive the "Response CRC Fail" error for all channels. I've also attempted to use combined control, employing Modbus for frequency control and starting from a digital input. Everything seems to function properly until I send the start command to the VFD. Interestingly, I consistently encounter the same error the moment I send the start command, regardless of whether I use register 40006 (high) or 40100 (1151). Could someone please assist me in resolving this issue?
Last updated: 2024-03-21

Post by andrea199403 on Assigning Modbus addresses to a structure in a dynamic way ^{CODESYS Forge talk (Post)}
Hello everyone, I am new to this forum and I am also new to Codesys programming. My problem is this: I have a STRUCT of 64 bool and 30 real, this STRUCT is assigned in the programme 9 times. Now I need to communicate with an HMI via Modbus and I have defined the slave device and created the holding registers for communication. I would like to declare the first call of the STRUCT on the Modbus registers %QX2000.0 to %QX2007.7 for the booleans and on the registers %QW1004 to %QW1034 for the real registers. That said, I would like to change an index and set an offset of 100 bytes for the calls of the other 8 assignments, so that the result is: %QX2100.0 to %QX2107.7 for the booleans and on the %QW1104 to %QW1134 registers for the Real registers, etc. Is there a way to declare this? Thank you very much.
Last updated: 2025-10-21

Post by aris on Modbus write via FB failure ^{CODESYS Forge talk (Post)}
Hi all, I am using CoDeSys V3.5 and a soft controller Win V3x64. I am trying to read a modbus slave via Function Blocks and not via the channels of the hardware tree for the Slave. I created some requests of type ModbusRequest and I notice that I can read Input Registers and Coils but I can not write Holding Registers and Coils. I am using the library IoDrvModbusTCP 4.1.0.0. When i just use a single modbus request with FC06 (or FC16), there is no request sent to the slave and although the xExecute takes its true value from a pulse of 2 seconds duration, I take almost every 3 minutes an error "TCP_COMMUNICATION_ERROR - 16#A5 - TCP Port. error. Request was not sent". My code is ok because if i change the function code for reading registers, everything works fine. Did anyone have this issue in the past? Thank you in advance.
Last updated: 2025-11-06

Post by ewi04 on Recipe Manager - RecipeManCommands, load & write wrong values, Bug? ^{CODESYS Forge talk (Post)}
Hallo, I have a strange problem with the recipe manager. ISSUE: When using RecipeManCommands not all values are loaded correctly. Saving a recipe with CreateRecipe(), ReadAndSaveRecipe() or ReadAndSaveRecipeAs() works without any problems. BUT: LoadRecipe(), WriteRecipe() or LoadFromAndWriteRecipe() do not load the data correctly. It is Interesting that we have a different error pattern with LoadRecipe() than with WriteRecipe() or LoadFromAndWriteRecipe(). LoadRecipe() does not load all data and WriteRecipe() or LoadFromAndWriteRecipe() overwrites some data or assigns it incorrectly. And it is also strange that LoadRecipe() writes the values to the PLC. Normally it doesn’t do it. It makes no difference whether the memory type is textual or binary. I have an object consisting of STRUCTs which is inserted in the recipe definition. Environment: Codesys V3.5 SP19 Patch 4 (64Bit), Recipe Management 4.2.0.0 *Add a project (reduced to the problem)
Last updated: 2023-11-15

Post by hazarath on How extract JSONElement containing Array data ^{CODESYS Forge talk (Post)}
I want to extract each element of an Array. Can someone help me with this. When I use JSONElementToString (part of JSON Utilities SL), I am seeing output as "ARRAY" instead of actual data. Here is the JSON content that I want to read : { "value1Unit": { "units": "M" }, "data": { "stepSize": 300.23, "points": [6,8] } } I would like to read each item of the element "points" i.e. 6 and 8. Here is the code I used, // Reading the content as JSON reader ( xExecute := execute , pwData := ADR ( converted_value ), jsonData := jsonDataStorage ); // Get the JSON Element jsonDataStorage.FindFirstValueByKey( wsKey := fidKeyVar, diStartIndex := searchElem, jsonElement => jsonElement ); JSON.JSONElementToString ( element := jsonElement , wsResult := valueWstring ); The content of the output of valueWstring is shown as "ARRAY" instead of the array items i.e. 6 and 8 Please can someone help me.
Last updated: 2024-07-30

Post by damian177 on Problem with downloading OPC UA tags by Data Source Manager ^{CODESYS Forge talk (Post)}
Hi, In Codesys V3.5 SP20, using Data Source Manager I am trying to connect to the OPC UA server and receive tags from it. The connection is ok, but the Codesys have a problem with downloading Tags group. The window (downloadingTags.jpg in attachement) never stop. After waiting for a while, I disconnect the connection and only the Server group remains downloaded, with OPC UA server diagnostic data (and this is read in Codesys). Of course, I tried connected via another OPC UA client : UaExpert , and everything works as it should, all tags are downloaded (Uaexpert.jpg screen). Has anyone on the forum encountered the OPC UA client configuration in Codesys? Is it possible to manually request the appropriate tags from the OPC server for reading in Codesys?
Last updated: 2024-09-03

Post by shabroz-gill on Exception when OPCUA datasource disconnects from Server ^{CODESYS Forge talk (Post)}
If i loose the network and the opcua data source suddenly looses connection with the server, i get an exception and my application stops working. I am using the latest version of the communication add v4.5.2.0 Is this a known issue? This makes the datasource unusable because it is inevitable that we will loose connectivity at some point, and the datasource crashing everything due to that seems to be a deal breaker. I can provide more details is someone from codesys is reading this. You can recreate is by just shutting off the Opc server after the codesys data source is connected and reading data from it. The codesys app does not crash everytime and sometimes it is able to reconnect without crashing, so you may have to try this a few times to see the exception. Best regards
Last updated: 2024-09-16

Post by taqamert on CANopen PDO Issue with Pressure Sensor in Codesys ^{CODESYS Forge talk (Post)}
Hello everyone, I am using an IFM CR0303 model PLC, which has a tilt sensor and a pressure sensor connected via CANopen. Both sensors are from the same brand (ATEK). I can read data from the tilt sensor without any issues, but I am unable to read data from the pressure sensor. I have added the EDS file in the PLC configuration and adjusted the node-ID settings. When I check with the PCAN-View application, I can see that the selected PDOs are coming through, but the data is not reaching the Codesys side. What could be the issue, and what can I try to resolve it? Can anyone help me?
Last updated: 2024-10-22

Post by rer-code on Codesys 3.5.18.60 – Application Loss and Persistent Data Corruption ^{CODESYS Forge talk (Post)}
Hi, I’m currently managing over 50 PLCs running Codesys version 3.5.18.60. At seemingly random intervals, some of these devices experience a failure where: All persistent variables are lost. Attempting to log in results in the message: “The application does not exist on device. Do you want to create it and proceed with download?” The log shows: “Loading retain-data/bootproject failed.” From what I’ve gathered, this may be due to a corrupted persistent data file, but I’m not entirely sure how to confirm or resolve this issue. If anyone has encountered something similar or has suggestions for troubleshooting or preventing this, I would greatly appreciate your input. Best regards
Last updated: 2025-08-19

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