Post by kuegerls on SysProcessExecuteCommand2 and CANopen Device ^{CODESYS Forge talk (Post)}
I have now conducted some tests. The problem occurs when the Python script establishes an OPCUA connection, even if I only establish the connection without reading or writing any data. Is there another way to exchange data between Python and CODESYS without having to put in a lot of effort?
Last updated: 2024-06-24

Post by pernockham on Pointer/reference to Codesys trend recording object? ^{CODESYS Forge talk (Post)}
I have a Hmi that acts as an interface for many (mostly identical) units. This is managed by a sort of "mux" where you select which unit that should be presented on the HMI. Backbone is solved by a HMI-gvl defined as reference/pointer to "unit-data", which then can be set to the individual units. While this works for most data I still have not sorted how to solve this for the trend recordings. One solution would be to have already "mux:ed" data values as source for the/one trend. However then the trend would contain data from different units/sources which could/will cause confusion. If its possible to "clear" this can be mitigated. Possibly let the trend have its own "mux-selector" (ie, the hmi are focusing on unit#3 however trend data is locked on unit#5), that could also work.. Or, let each unit have its own trend recording, which is focused if the unit is "selected". Can I reach the trend recording objects programmatically (those defined in the device tree)? Ie, can I use a "reference/pointer to these trend recording objects"? There is a field "data source" in the trend properties dialog which seems to resemble what Im looking for? But Im not sure if I can use it in some way, I cannot change anything in this field it only says <local application="">. </local>
Last updated: 2025-09-16

Post by e13740e on Parameterized Property syntax for array element processing ^{CODESYS Forge talk (Post)}
Since parameterized (indexed) properties are not possible, I decided to use architectural approach "Indexing Property Adapter" to achieve the intended goal — avoiding code duplication for validated access to array elements. Essence: Create a Function Block Adapter (FB_PropertyAdapter) that encapsulates the logic for working with a single element of the target array (e.g., with one settings structure). Declare Properties inside the adapter block for accessing each individual field of the data structure. All validation logic is implemented within the Set accessors of these properties. Data Binding via VAR_IN_OUT: The adapter block receives a reference to a specific data element from the global array through its VAR_IN_OUT section, which ensures direct work with the original data without copying. Create an Array of Adapters: In the parent POU (e.g., FB_SettingsManager), an array of these adapter blocks is created — one for each element of the global array that needs to be managed. Initialize Bindings: In a FOR loop, each adapter instance from the array is given a reference to the corresponding data element. Result: This approach allows accessing the data via the index of the adapter array, and then through the property name, which simulates the behavior of an indexed property: MyAdapterArray[Index].MyProperty Thus, the validation and data access logic is written only once inside the adapter block and is then reused multiple times by creating instances of it in an array. This completely solves the problem of code duplication while providing a clean, scalable, and object-oriented architecture compatible with standard CODESYS features. Question closed.
Last updated: 2025-10-19

Post by edvard-munch on How I can get "Done flag" for "Modbus Slave Channel"? ^{CODESYS Forge talk (Post)}
This is from 10 years ago, I know. But I have been using (SLAVE_DEVICE.iChannelIndex = CHANNEL_NUMBER) AND (SLAVE_DEVICE.xDone) I suppose that it shows xDone for the channel that shows up in the iChannelIndex at the same cycle? It seems to be working properly for two devices that I have been using it before But now I have another device and using two write channels, for one register each. One channel works properly and returns DONE flag When another channel is triggered, I see that it shows up in iChannelIndex, but flag DONE not received, but no Error for the channel. Also, when i check the register in the device it's evident that data has been transferred. Is this could happen sometimes with CODESYS, so DONE flag not received? Or this is a problem with a given device? With this certain register
Last updated: 2024-12-19

Post by xiaolo on Raspberry Pi 5 ^{CODESYS Forge talk (Post)}
Does Ver. 4.12 support Raspberry Pi 5? I have three issues. The first issue is that Codesys cannot detect the RPI 5 when I want to download the runtime. When assigning the IP Address manually then I can download the runtime. The second issue is that I cannot connect to the RPI to download a program. Sometimes the window pops up and it ask for the user credentials, but it is still not connecting. The third issue is that I cannot connect to an ESP32 configured as a Modbus Slave with a Raspberry Pi 4B. I can connect to the ESP32 via a Radzio! Modbus Master Simulator. I am also missing the function Write Holding Registers in the setup of the slave. Are this known issues and when it will be solved?
Last updated: 2024-07-12

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 garrian on How to write multiple coils (Modbus FC15) ^{CODESYS Forge talk (Post)}
Hi there! I'm testing out modbus TCP/IP for my home brewery, using Wago PFC200 as both slave and master. I'm using Wago library WagoAppPlcModbus. Holding registers, input registers' and discrete inputs works fine, but when trying to write multiple coils, it doesn't work. Any idea what I'm doing wrong here? Attached is a screenshot of my code. I tried both using bit mapping and without. If I change to FC05, and write only 1 coil at the time, it works fine. But I want to write all at the same time.. Any help is very appreciated :)
Last updated: 2024-11-16

Post by alexgooi on Codesys licensing explanation ^{CODESYS Forge talk (Post)}
Dear Forum, We are currently switching to a native Codesys controller, and I'm currently trying to determine the correct license. I have a question regarding the Modbus instances. With the Standard S license this is set to 4 (See picture). In our projects we are using a lot of communications to Modbus servers using a Codesys Controller, for this communication I'm using the ModbusFB library (supplied by 3S) (see picture). In my project I would like to use more than 4 instances of the ClientTCP FB. My question is, is this now capped at 4 possible connections with the standard S license. Or do these function blocks have a different relation with the license? Some clarity on this topic would be very welcome. Thank you in advance
Last updated: 2024-02-15

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 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 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

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