Post by grant32 on RAMP_REAL FB is retaining my output value when i try to re use the FB ^{CODESYS Forge talk (Post)}
Hello, I'm relatively new to PLC programming. I am trying to creat a ramp down function, I have an example here of what I am using. I can get the function to work, the issue is that the OUT (variable3) value is being held by the FB so after I use it once it no longer works. In this example i set variable3 to 100 and the rest is as seen, over the course of a minute it ramped down to 10 (as desired). But when I deenergize TEST_START, set variable3 back to 100, and then re-energize TEST_START it immediately jumps back to the previously held value 10. The reset on this block just pauses the function and holds the last OUT. In my case I will need the function to start OUT at a set value, ramp down to the IN (variable2) value, and then accept a new OUT value to ramp down next time the block is energized. Hopefully this made sense, if anyone has any advice that would be awesome!
Last updated: 2024-07-29

Post by kiranbsiddaiah on CodeSys OPC UA client Unable to Connect To OPC UA sever through Username and password ^{CODESYS Forge talk (Post)}
Hi, I'm using codesys v3.5 sp21 software. I have downloaded the sample opc ua client project from https://content.helpme-codesys.com/en/CODESYS%20Examples/_ex_uacapi_example.html and i tested connecting to "prosys opc ua simulation server". Through Anonymous connection it is connecting to server and can read data. Later tried to connect using username and password. First got a SECURITY_CHECKS_FAILED error, trusted the client certificate in the server and this issue resolved. Next got an INVALID_CERTIFICATE error, trusted the server certificate in the client and this issue resolved. After these two error it is not establishing the connection and not giving any error messages. UAAsyncProp: UA.AsyncProperty := (tnTaskName:='UAClientTask', usiTaskPrio:=20, udiTaskInterval:=10000); UAPolicy: UA.SecurityPolicy := (sPolicy:=UA.OpcUa_SecurityPolicy.OpcUa_SecurityPolicy_Aes128Sha256RsaOaep, eSecurity:=UA.SECURITY_MODE.SIGN_AND_ENCRYPT); //UAPolicy: UA.SecurityPolicy := (sPolicy:=UA.OpcUa_SecurityPolicy.OpcUa_SecurityPolicy_None, eSecurity:=UA.SECURITY_MODE.NONE); UAAuth: UA.UserNameAuth := (sUserName:=UAVars.sUser, sPassword:=UAVars.sPass); UAClient: UA.Client := ( itfAsyncProperty:= UAAsyncProp, //sClientName:= 'MyOPC UA client name', //default: ‘CODESYS OPC UA Client’ sURL:= UAVars.sURL, sSession:= UAVars.sSession, itfPolicy:= UAPolicy, itfAuth:=UAAuth, udiTimeout:= 100000 //,itfNamespaceArray:= UAVars.itfNamespaceArray //optional use ); ----------------------------------------------------------------------------------------------------------------------- Please let me know if any additional information required. Thank you...
Last updated: 2026-05-07

Post by e13740e on Parameterized Property syntax for array element processing ^{CODESYS Forge talk (Post)}
Hello. I'm trying to create a Parameterized Property(CDS V3.5 SP21) to avoid copy-pasting code for processing array elements. I can't seem to get any result. Perhaps I am making a mistake with the syntax. None of the declaration options below are accepted by the compiler. If you know and use them (Parameterized Properties) in your work, please let me know. Thank you in advance. Option 1: PROPERTY <property_name> : <data_type> VAR_INPUT // One or more index parameters are declared here <index_name> : <index_type>; END_VAR</index_type></index_name></data_type></property_name> // Accessor for reading GET // Code that uses <Index_Name> to return a value END_GET // Accessor for writing SET // Code that uses <Index_Name> and // the implicit variable <Property_Name> to write a value END_SET END_PROPERTY Option 2: PROPERTY <property_name> (<index_name> : <index_type>) : <data_type></data_type></index_type></index_name></property_name> // Accessor for reading GET // Code that uses <Index_Name> to return a value END_GET // Accessor for writing SET // Code that uses <Index_Name> and // the implicit variable <Property_Name> to write a value END_SET END_PROPERTY
Last updated: 2025-10-09

Post by dhumphries on Minimum system requirements for codesys control standard S ^{CODESYS Forge talk (Post)}
I'm working on a low cost project and I'm considering installing the Codesys runtime on a PC running Linux Debian instead of buying a PLC with a pre-installed runtime. For my needs the Control Standard S license should be capable of running some IO over ethernet/ip, and a webvisu. The PC I am considering has a AMD GX-424CC 2.4GHz processor (4 core/4 thread) and 4GB RAM. This may compare to a raspberry pi4, but I know an X86 processor doesn't directly compare to an ARM processor, and a processor can have a high clock speed but other factors like L2/L3 cache can influence the overall performance. I can't find any published specs for the processor and RAM requirements to run the Codesys Control runtime, does anybody have a link to the minimum system requirements or experience using devices that are at or below the minimum system requirements. A raspberry pi with the control for raspberry pi SL runtime license would be the lowest cost option, but the license is not for commerical use. This restriction is somewhat vague, can anybody clarify if this means I can use a raspberry Pi runtime for in-house automation, what about if I am selling an integrated system that uses a raspberry Pi as a controller?
Last updated: 2023-12-25

Post by alex00 on DCS / Central Engineering for Codesys ^{CODESYS Forge talk (Post)}
Hello together I'm currently investing in possibilities to have a central engineering software / system for Codesys based controllers. Something like a DCS / SCADA depending on where you see the functionality. We plan to use more or less vanilla codesys. The tool should support the following: - Connect to multiple PLC's in a project to see its variables and debug it. - Central Engineering capabilities (for example shared libraries in a project). - Download the new code / binaries to the plc. - Maybe have functionality to combine visualization elements and logic together. - See the live status variables on all the systems (crosscommunication). I see that codesys theoretically supports engineering of multiple PLC's, but I couldnt find to much functionality for a DCS type of operation, but that could be lack of knowledge. Any tips from you? Is Codesys good enough for this and maybe there are some manufacturers which build around it? Or are there good tools on the market with Codesys support (and the engineering is separate, but download to codesys possible). The use case is distributed energy installations like Heating pumps, Photovoltaics, etc. All these installations should have a PLC with codesys installed and run in one larger network, the PLC's are connected via VPN. Thanks for your inputs Greetings
Last updated: 2024-02-19

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 kunal-pinetics on USB Communication for IP Configuration & Application Update – STM32H Series PLC ^{CODESYS Forge talk (Post)}
Hello everyone, I am currently working on a PLC device based on the STM32H series MCU, running CODESYS. At the moment, I can: Change the Ethernet IP address Update/download the PLC application via Ethernet without any issues. However, I would like to implement the same functionality over USB (or Serial via USB) instead of Ethernet. My goals are: Change the device’s Ethernet IP address via USB Download/update the PLC application via USB communication Possibly use USB as a service/programming interface The hardware platform is based on STM32H series, and I am looking for guidance on: Whether CODESYS supports USB device communication for runtime download If a custom USB CDC (Virtual COM Port) implementation is required Whether a specific CODESYS runtime configuration is needed If a bootloader approach is recommended for application updates via USB If anyone has experience implementing USB communication for runtime download or device configuration on an STM32-based PLC, I would really appreciate your guidance. Thank you in advance for your help.
Last updated: 2026-02-26

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