Post by alexgooi on Modbus writing on value change ^{CODESYS Forge talk (Post)}
The way I usally tackle this is by syncing only words (then you are able to use the FB above). If you then want to write a Boolean simply type it like this. Value[1].0 := Bool1; Value[1].1 := Bool2; Value[1].2 := Bool3; Uints have the same number of bits than a INT/WORD so these ones will work as well (they are only represented diffrently). A Real will work but you will loose some infomration in the conversion. If you want to keep the information you can convert 2 words to a float with a function (for example with the IEEE-754 standard) . In this way the syncing to the server is very simple and in the Codesys Program you decide what part of the word you want to use.
Last updated: 2024-04-03

Post by dhumphries on Deploy Codesys Control SL to a 'secure' device ^{CODESYS Forge talk (Post)}
I have the same problem on a setup where I'm trying to load control SL onto a fresh installation of ubuntu server 22.04 (with sudo privileges,) I've done this in the past several times but only with codesys 3.5.19.x since updating to the new versions I'm having inconsistencies, either I can load the runtime but not login or I can't load the runtime at all. I appreciate there are new releases frequently, but it would be nice if there was a LTS version with some kind of documentation. I'm currently building a VM so I can install version 3.5.19.4 since this was the last version that worked for me. Adding additional versions through codesys installer has been unsuccessful, hopefully a fresh install on a virgin OS will be more successful.
Last updated: 2026-08-10

Post by pernockham on Gateway in China - "Gateway not connected" ^{CODESYS Forge talk (Post)}
I think I understand my problem. They are most probably related to configuration of the network. When I use DHCP for the unit to my router it all works. However when using static IP I have not managed to reach functioning state. Trying to replicate the situation on my desk. Having a static IP on the "debian host" and a connection to my computer which then routes traffic on to internet. I have entered settings for gateway and netmask. I can ping from my "debian plc host" to internet and also do "curl google.com" so traffic seems to find its way through and back, still "Automation server" will not find the gateway. Any hints how a manual configuration should be done? Is it possibly a "firewall" issue of my "normal router"? Thanks for any help! Per
Last updated: 2026-01-27

Post by gilbert-mh on CAA net base TCP client cause PLC to crash - Kernel message : N0HZ_local_softirq_pending 80 ^{CODESYS Forge talk (Post)}
Hello all, I have been trying to implement a TCP client on a Festo PLC (CPX-E-CEC-M1) and it looks like it works well except that after some time (greatly varies between a few hours to more than 100h) my PLC crash. When I look into the log file the only thing I see is that before the crash happens a few kernel warnings : N0HZ_local_softirq_pending 80 and then the crash. I've looked into this warning and from what I could find on the net it seems that this is warning is triggered when the ethernet link is down. I've tried to correct this bug for quite some time and what I know is that : - The crash is caused by my TCP client, when I remove it from my code I see no crash - The crash happens more quickly the more the TCP client is used. - The time before the crash is not directly proportional to the number of communications or their size. But it looks like it is just more likely to happen if the client connect to the server at a higher frequency. - The precedent observation makes it seem unlikely that the crash is caused by some memory overflow because then the crash speed would be more proportional to the amount of data exchanged. SO from these observations, I believe that the crash could be caused by the PLC trying to connect to a server while there is some kind of issue with the ethernet link resulting in the PLC getting stuck in some indefinite state and making it crash. This still seems a bit unlikely to me because if the ethernet is down it simply shouldn't be able to contact the server and the communication would just fail which doesn't cause my PLC to crash. Has anyone encountered the same kind of problem (with the same kernel message) ? I am pretty sure the warning is not the direct cause of the crash but just an indicator that something is wrong with my PLC. Thanks in advance
Last updated: 2024-01-12

Post by domebruce on TCP communication and TCP Streams ^{CODESYS Forge talk (Post)}
Hello, I'm doing some tests with TCP communication using Reader, Writer and TCP_Process components from NBS 4.0. I'm having a really hard time finding documentation and examples on these components. I found a very simple and incomplete example here: https://forge.codesys.com/prj/codesys-example/nbs/home/Home/. The documentation is also insufficient: it only provides the names of the FBs, Methods and their parameters, but no descriptions about how to use them. Do you have any suggestions on where to find more support? More generally, why is the free online CoDeSys documentation so poor? What do you think? Thanks Domenico Canavero
Last updated: 2026-06-16

Reading from a file, a line of CSV values with CrLf at the end of the line. ^{CODESYS Forge talk (Thread)}
Reading from a file, a line of CSV values with CrLf at the end of the line.
Last updated: 2018-09-18

Post by tk096 on Confused by dwIpoTime input for SMC_Interpolator ^{CODESYS Forge talk (Post)}
Hi, dwIpoTime should be set to the cycle time of your motion task. It defines the interpolation interval of the interpolator. E.g. in the attached screenshot, the task has a task interval of 4ms. The dwIpoTime input of the interpolator should be set to 4000.
Last updated: 2024-07-22

Post by timvh on Array of Program ^{CODESYS Forge talk (Post)}
You cannot create an array of Programs. Create a Function Block for this purpose instead of a program. You can create an array of FB instances and call each instance in a loop.
Last updated: 2024-09-03

Post by nonstop-cat on Problem of assigning physical addresses to variables of type ARRAY OF ARRAY as MW and QW ^{CODESYS Forge talk (Post)}
Array writing method error,,,<arrayname>: ARRAY [<ll1>..<ul1>, <ll2>..<ul2>, <ll3>..<ul3>]</ul3></ll3></ul2></ll2></ul1></ll1> OF <basedatatype></basedatatype></arrayname>
Last updated: 2025-03-31

Post by nonstop-cat on Problem of assigning physical addresses to variables of type ARRAY OF ARRAY as MW and QW ^{CODESYS Forge talk (Post)}
Array writing method error,,,<arrayname>: ARRAY [<ll1>..<ul1>, <ll2>..<ul2>, <ll3>..<ul3>]</ul3></ll3></ul2></ll2></ul1></ll1> OF <basedatatype></basedatatype></arrayname>
Last updated: 2025-03-31

Is it possible to link an array of bits to an alarm group to show a lot of alarms at once? ^{CODESYS Forge talk (Thread)}
Is it possible to link an array of bits to an alarm group to show a lot of alarms at once?
Last updated: 2021-07-08

Size of the abyPoolMemory input when creating an fb for the purpose of fb creation (fb extends Factorybase from the fbFactory Library) ^{CODESYS Forge talk (Thread)}
Size of the abyPoolMemory input when creating an fb for the purpose of fb creation (fb extends Factorybase from the fbFactory Library)
Last updated: 2023-01-15

Codesys Forge Unit Testing Framework [Announcement of the new CfUnit release: v1.1.0.0 ETA 1st quarter of 2020] ^{CODESYS Forge talk (Thread)}
Codesys Forge Unit Testing Framework [Announcement of the new CfUnit release: v1.1.0.0 ETA 1st quarter of 2020]
Last updated: 2019-06-16

Codesys Forge Unit Testing Framework [Announcement of the new CfUnit release: v1.1.0.0 ETA 1st quarter of 2020] ^{CODESYS Forge talk (Thread)}
Codesys Forge Unit Testing Framework [Announcement of the new CfUnit release: v1.1.0.0 ETA 1st quarter of 2020]
Last updated: 2019-06-16

Post by jeffyech on <Dereference of invalid pointer> ^{CODESYS Forge talk (Post)}
I have a program which calls a structure. while online with the PLC, I get: <dereference of="" invalid="" pointer=""> in the declaration values area. What are the causes of this? Can it be solved?</dereference> Version 3.5 of codesys.
Last updated: 2026-06-25

The element of type 'VisuFbElemImage' could not be updated. Reason: Index was outside the bounds of the array. ^{CODESYS Forge talk (Thread)}
The element of type 'VisuFbElemImage' could not be updated. Reason: Index was outside the bounds of the array.
Last updated: 2026-01-27

Post by jasonhogan on Login problem with FileTransfer on Raspberry Pi 5 ^{CODESYS Forge talk (Post)}
That’s a classic CODESYS quirk. As soon as you enable AllowFileTransferServices=1, the web server locks down and demands authentication for everything, including WebVisu sessions. Since you're on a Raspberry Pi / Linux, trying to make the built-in CODESYS web server do both secure file handling and unauthenticated kiosk visu is usually a losing battle. A couple of ways to get around this: The cleaner route (separate the jobs): Turn AllowFileTransferServices back off in the config so your kiosk WebVisu opens freely without any login prompts. Then, handle the file download outside of CODESYS — just run a dead-simple Nginx/lighttpd file server or a tiny Python script on the Pi pointed at your export folder (/var/opt/codesys/...). That way your PLC security stays intact, and the kiosk screen just works. If you really want it through CODESYS: Check your Device -> Users and Groups in the IDE. Make sure the Everyone / Anonymous user group actually has explicit view permissions checked for the Visualization. Sometimes when file services are toggled, anonymous users lose the default visu-read rights and get booted straight to the login dialog. URL / Browser trick for kiosk: If the Pi is just opening a local browser on startup, you can sometimes pass the basic credentials in the browser launch script or use a small reverse proxy on localhost to inject the headers automatically so you don't see the popup. Honestly, running a lightweight HTTP/FTP endpoint on Linux (option 1) is by far the least headache.
Last updated: 2026-08-15

Post by yannickasselin on MQTT QoS 1 & 2 ^{CODESYS Forge talk (Post)}
Hello, After some more tests, here is what I found out. It seems we have to increase the uiKeepAlive and tPingInterval parameters. If I increase the uiKeepAlive value to 60s and the tPingInterval to 30s, then if I disconnect the ethernet cable from Codesys and publish some messages to which Codesys subscribes to and then reconnect within 30s, I will get the messages. If I don't reconnect the cable within 30s (ping interval), the client goes in error with "ACKNOWLEDGE_TIMEOUT". When this happens, it will not automatically reconnect after reconnecting the cable. I have to disable and re-enable the client but I will not get the published messages. I need to do more tests because there are a lot of weird things happening when playing with the ping interval and the keep alive. It is not clear to me what does what. I even ended up not receiving messages anymore, even if I disabled and re-enabled the mqtt client. The client did not give any error. The only way I was able to get messages again was by modifying my client ID. After that, if I try to re-use one of the old client IDs, nothing works (publish, subscribe) and I get a TCP_INIT_ERROR and sometimes a TCP_READ_ERROR. I need more explanation/documentation about these weird behaviors. Maybe it is the way I use it, maybe it is related to the broker (I am using Mosquitto with default parameters). When using a Node-Red client, everything works perfectly. I am trying to achieve the same behavior with Codesys but it seems impossible so far.
Last updated: 2024-10-30

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 mil581 on Modbus TCP Server connection is ESTABLISHED but all holding registers are value 0? ^{CODESYS Forge talk (Post)}
Hello everyone! I'm facing a weird issue with CODESYS Control Win V3 x64 on a fresh Windows install. The situation is as follows: CODESYS Modbus TCP Server (Slave) is running and I can see live values in the mapping display of Modbus settings: GVL (e.g., 32, 42, 50). Port 502 is LISTENING according to netstat. When connecting via Modbus Poll or Node-RED, the connection status changes to ESTABLISHED and everything reports as fine. The Problem: Despite the successful connection, all holding registers return 0 no matter what. It's like the OS accepts the TCP handshake, the request counter goes up but the data payload never reaches Modbus Client (in this case Node-RED or Modbus Poll). Quick Stats: Firewall: Completely OFF. Unit ID: Verified & Matching. IP: Tried 127.0.0.1 and 192.168.0.1. Interface: Correctly bound in Ethernet Device settings. I already tried absolutely everything from changing IP address, subnet, port, deleting the project and starting new one and even nuking my old Windows install. Since I am near completion of my bachelor thesis only thing left for me to do is connect SoftPLC to NodeRED via Modbus but this issue is driving me crazy for weeks. I do not know what to do anymore.
Last updated: 2025-12-25

Post by austin on Is the Realtek RTL8119I-CG ethernet controler on supported list? ^{CODESYS Forge talk (Post)}
We have a pc with Realtek RTL8119I-CG PCIE 1.1 giga LAN ethernet controller Does this RTL8119I-CG support Codesys?
Last updated: 2024-09-04

Post by austin on Is the Realtek RTL8119I-CG ethernet controler on supported list? ^{CODESYS Forge talk (Post)}
We have a pc with Realtek RTL8119I-CG PCIE 1.1 giga LAN ethernet controller Does this RTL8119I-CG support Codesys?
Last updated: 2024-09-04

Post by austin on Is the Realtek RTL8119I-CG ethernet controler on supported list? ^{CODESYS Forge talk (Post)}
We have a pc with Realtek RTL8119I-CG PCIE 1.1 giga LAN ethernet controller Does this RTL8119I-CG support Codesys?
Last updated: 2024-09-04

Post by egau on No option to create "Parameter List" in library ^{CODESYS Forge talk (Post)}
Hi, pretty late to the party, but did the "defining constants per FB instance" actually became a thing? @ingo
Last updated: 2024-10-07

Post by jeroenaero on CodeSys Raspberry pi I2C driver not found ^{CODESYS Forge talk (Post)}
I tested your project but with same results i am still not seeing analog values. I also included the library list, the mainprogram.
Last updated: 2024-11-08

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