Post by tcarlbom on Read tag values using external program ^{CODESYS Forge talk (Post)}
This is my first time posting in this forum and I am new to codesys. I am a fullstack developer and I am trying to figure out how the following. What would be the best approach to create a own/custom tag browser? Either directly in codesys ide or using a separate custom program (perhaps a winforms application). 1.a. Shall I parse the .project xml file to get a list of all tags in the project? 1b. Shall I use python scripting in codesys ide to get a list of tags? Once one have selected some tags. These tags shall be exposed to a python program which will be acting as a edge computer. It’s fine to be able to import a file. 2a. I found a library called codesys plchandler which (as I understand) acts a rest api server. Is this correct? If so, can I query the api from a custom python script, ie can query what tags exist in project and or read tag values? My research so far. From earlier projects I know that using opc ua would be perfect for this but from my opinion it’s bloating the plc since it’s resource intensive. So opc ua is not an option. Codesys automation server is neat. But I don’t want to rely on some cloud services and subscription based pricing. There seem to be several interesting codesys libraries like mqtt, tcp server and NVL sender which would help me expose plc tags. But all have a common problem. One have to manually write what tags which will be used in these function blocks. I want a similar experience like “selecting” tags in the opc ua or the codesys tracing, ie a tag browser.
Last updated: 2024-06-28

Post by fmon on Modbus : dis- / re-connect cable: modbus does not re-start ^{CODESYS Forge talk (Post)}
Hello, I am using codesys Modbus TCP client (4.4.0.0) to communicate with a python modbus server (package pyModbusTCP). I first start my python server on the distant machine. After a fresh codesys compilation, a plc connection/transfer and a PLC run, the modbus connection is OK. Every time in this context the connection is created correctly. When I shut down the server, the modbus connection falls, that is normal. When I restart the python server, impossible to recreate the modbus connexion. With the client autoreconnection, I see on my server that the client tries to connect but unsuccesfully. I have the following message : DEBUG:pyModbusTCP.server:accept new connection from ClientInfo(address='192.168.1.20', port=33476) DEBUG:pyModbusTCP.server:Exception during request handling: NetworkError('recv return null') I tried to stop the codesys client and to restart it with these commands : Modbus_TCP_Client.xStop := True; // Or False Modbus_TCP_Client.Enable := True; // Or False Modbus_TCP_Server.Enable := True; // Or False I tried to confirm the error manually to force reconnection with: Modbus_TCP_Server_Motors.xConfirmError := TRUE; I tried also this command to STOP/RESET/START client and server (codesys side) but nothing happens : status_client := Modbus_TCP_Client.SetCommunicationState(eRequestedState := DED.DEVICE_TRANSITION_STATE.STOP); // .RESET & .START The answer of this function when executed is "status_client = NOT_SUPPORTED" It seems that is a socket problem, but I do not understand if it is on the client or server side. I tried a modbus simulator called "ananas.exe" and the result is the same. Impossible to get a modbus reconnection. What is different at the first connection and at a reconnection attempt ? Thanks for your help
Last updated: 2025-03-14

Post by fmon on Modbus TCP client reconnection problem ^{CODESYS Forge talk (Post)}
Hello, I am using codesys Modbus TCP client (4.4.0.0) to communicate with a python modbus server (package pyModbusTCP). I first start my python server on the distant machine. After a fresh codesys compilation, a plc connection/transfer and a PLC run, the modbus connection is OK. Every time in this context the connection is created correctly. When I shut down the server, the modbus connection falls, that is normal. When I restart the python server, impossible to recreate the modbus connexion. With the client autoreconnection, I see on my server that the client tries to connect but unsuccesfully. I have the following message : DEBUG:pyModbusTCP.server:accept new connection from ClientInfo(address='192.168.1.20', port=33476) DEBUG:pyModbusTCP.server:Exception during request handling: NetworkError('recv return null') I tried to stop the codesys client and to restart it with these commands : Modbus_TCP_Client.xStop := True; // Or False Modbus_TCP_Client.Enable := True; // Or False Modbus_TCP_Server.Enable := True; // Or False I tried to confirm the error manually to force reconnection with: Modbus_TCP_Server_Motors.xConfirmError := TRUE; I tried also this command to STOP/RESET/START client and server (codesys side) but nothing happens : status_client := Modbus_TCP_Client.SetCommunicationState(eRequestedState := DED.DEVICE_TRANSITION_STATE.STOP); // .RESET & .START The answer of this function when executed is "status_client = NOT_SUPPORTED". Is it normal ? It seems that is a socket problem, but I do not understand if it is on the client or server side. I tried a modbus simulator called "ananas.exe" and the result is the same. Impossible to get a modbus client reconnection. What is different at the first client connection and at a reconnection attempt ? Thanks for your help
Last updated: 2025-03-17

Post by dnordenberg on BOOL variable in OPC UA and modbus simultaneously ^{CODESYS Forge talk (Post)}
How can I have an BOOL variable that is read/write in both modbus TCP server and from OPC UA at the same time? Variables with %MX.n %QX.n addressing which is used for BOOL/coils in modbus server is not allowed in OPC UA symbol list on Schneider M251 controllers. I have already asked on Schneiders forum but there are not a lot of codesys experts over there :( So OPC symbols can't have a address and the modbus TCP server needs a address. So how should I do it then? It seems like an impossible combination. Since I want read/write access from both ways I can't just simply make a second variable and assign it the value of another since it would be a one way assignment. I also tried using VAR_CONFIG which then makes the address syntax %Q or %M in my main variable list and that fools OPC UA Symbol Configuration to allow it and then I add the complete %MX.n address of it in the VAR_CONFIG list. This semi works, I can toggle the BOOL from modbus but the OPC UA symbol seems to be read only. It displays symbol status but nothing happens when I toogle it. I think I need another way to have the variables and symbols pointing to the same bits in memory... My plan B is to write a BOOL array compare FB that saves a history bit from previous cycle and if that does not match current status at next cycle for either the OPC symbol or the modbus variable then it copies the new status over to the other. Maybe ugly but it's like my last alternative. Kind regards David
Last updated: 2025-07-14

Post by serwis on Dynamic target position tracking ^{CODESYS Forge talk (Post)}
Hello, I am trying to control a servo drive and dynamically set its position. I control the drive via EtherCAT with a cycle time of 500us. I use the MC_MoveAbsolute block for this. The problem is that when using a PID controller, I generate the positions I want the drive to move to on an ongoing basis, and I would like the position to be set immediately. The MC_MoveAbsolute block must receive a rising edge to execute, and I would like the movement to be performed without waiting for this edge. I have created a function that generates a rising edge every 1 ms, but I am unable to change this time to 500 µs because the TON function does not support times shorter than 1 ms. Below is the code to call the rising edge: IF Exe = TRUE THEN delay1(IN:=TRUE, PT:=T#1MS); IF delay1.Q = TRUE THEN Exe := FALSE; delay1(IN:=FALSE); END_IF END_IF IF Exe = FALSE THEN delay(IN:=TRUE, PT:=T#1MS); IF delay.Q = TRUE THEN Exe := TRUE; delay(IN:=FALSE); END_IF END_IF END_IF Here is the code for calling the MC_MoveAbsolute function: MoveDegree( Axis:= Tilt, Execute:= Exe, Position:= position_target - (base_angle_real * feedforward_turn), Velocity:= vel, Acceleration:= acc, Deceleration:= dec, Jerk:= jerk, Direction:= MC_DIRECTION.shortest, BufferMode:= MC_BUFFER_MODE.Aborting, Done=> , Busy=> , Active=> , CommandAborted=> , Error=> , ErrorID=> ); I realize that there are probably better methods for performing this type of task. How can I implement motion with a dynamically changing setpoint? THANKS
Last updated: 2025-09-05

Post by testlogic on Sending Sequential Modbus TCP Packets ^{CODESYS Forge talk (Post)}
I have a Modbus TCP slave device where I need to do sequential writes to the same register. The register I'm writing to is kind of like a command line, each packet is a command word encoded in Hexadecimal. I am having difficulty implementing this system in CoDeSys 3.5 SP19. I feel like the structure of the program should be something along the lines of (Pseudocode): ModbusTCPSend(Command Register, Command1) ModbusTCPSend(Command Register, Command2) ModbusTCPSend(Command Register, Command3) I have tried to implement this with a rising edge trigger wMot1OPCode := 16#E1; //Stop Motor & Kill Program xMot1SendOP := TRUE; //Send OP on rising edge xMot1SendOP := FALSE; //Reset wMot1OPCode := 16#9E; //Disable Motor xMot1SendOP :=TRUE; //Send OP on rising edge xMot1SendOP := FALSE; //Reset Where "wMot1OPCode" is the IO map for writing to the command register, and "xMot1SendOP" is the rising edge trigger for that modbus channel. However, this doesn't work. The device never responds to the modbus commands. It seems like the trigger variable is switched too quickly for modbus to send the packet. I know the modbus register is working, because I can set the channel to cyclic and the device will respond. However, I can't use this reliably because I need each command to be sent once, in order. Cyclic keeps re-sending the commands and seems like it could miss a command as well if one was sent in-between cycle time. I have also trying using the Application trigger as described by https://faq.codesys.com/pages/viewpage.action?pageId=24510480, but this is also not working for me. See attached picture for my FBD code. This seems like a simple function, I can't tell what I'm doing wrong here. Thanks for the help.
Last updated: 2024-03-06

Post by olehmann03 on PFC200 - WAGO 750-8202 - MODBUS RTU ^{CODESYS Forge talk (Post)}
Hello, I’m working on implementing Modbus RTU communication with a Carel controller (CPCO). I want to use the front RS485 interface through the DB9 connector. The issue is that I can’t get the communication working correctly. Below are the steps I’ve done so far: Connected pins 3 and 8 from the DB9 connector to the +/- RX/TX terminals on the Carel side. In the PLC shell, I set serialmode to RS485. In WBM under Administration > Serial Interface > Assign owner of serial interface, I set the port to unassigned. In the device tree, I created Modbus_COM with the following settings: COM port: 1 Baud rate: 19200 Parity: None Stop bits: 1 Created a Modbus client on this COM interface in RTU mode. Under the status tab, I can see it is in running state. On the client, I created a Modbus server and set the Modbus address of my unit to 1. Defined a few channels as FC03 to read holding registers according to the Carel register map. I checked the communication with the Carel controller using a USB-to-RS485 converter connected to my PC, and communication works correctly there. In the status tab, I can see that the Modbus server is polling, but there is no response from the controller. I also tried multiple times swapping A/B lines on the Carel side, but it did not help. Do you have any suggestions on what else I should check?
Last updated: 2026-05-22

Post by olehmann03 on PFC200 - WAGO 750-8202 - MODBUS RTU ^{CODESYS Forge talk (Post)}
Hello, I’m working on implementing Modbus RTU communication with a Carel controller (CPCO). I want to use the front RS485 interface through the DB9 connector. The issue is that I can’t get the communication working correctly. Below are the steps I’ve done so far: Connected pins 3 and 8 from the DB9 connector to the +/- RX/TX terminals on the Carel side. In the PLC shell, I set serialmode to RS485. In WBM under Administration > Serial Interface > Assign owner of serial interface, I set the port to unassigned. In the device tree, I created Modbus_COM with the following settings: COM port: 1 Baud rate: 19200 Parity: None Stop bits: 1 Created a Modbus client on this COM interface in RTU mode. Under the status tab, I can see it is in running state. On the client, I created a Modbus server and set the Modbus address of my unit to 1. Defined a few channels as FC03 to read holding registers according to the Carel register map. I checked the communication with the Carel controller using a USB-to-RS485 converter connected to my PC, and communication works correctly there. In the status tab, I can see that the Modbus server is polling, but there is no response from the controller. I also tried multiple times swapping A/B lines on the Carel side, but it did not help. Do you have any suggestions on what else I should check?
Last updated: 2026-05-22

Post by rmarco on Generic Variables and FDB ^{CODESYS Forge talk (Post)}
Hello everyone, I am running into a highly frustrating issue in the FBD editor regarding a Function Block with generic constants (VAR_GENERIC CONSTANT). I created a FB using ST, with a generic var, useful for having a variable sized array, as follows: FUNCTION_BLOCK Coil VAR_GENERIC CONSTANT maxEvents: USINT := 5; END_VAR VAR events: ARRAY[0..maxEvents-1] OF IEvent; END_VAR These FBs have also several methods. I declare them as follows in code: VAR coil1: CDL.Coil<(maxEvents:=1)>; END_VAR and when using them in ST, I have no problems. However, when trying to use them in FDB, I do not know how to do that, as some strange misalignment happens. Here's what happens: When I add the block to my FBD canvas and assign coil1 as the instance name, the compiler throws this error: 'coil1' is not an instance of 'CDL.Coil<(maxEvents:=1)>'. Same occurs when I try to instantiate blocks such as 'coil1.turnOn' or similar. Here is what I have already tried, none of which worked: - Deleting the <(maxEvents:=1)> parameter from the text inside the FBD box. - Deleting the block entirely, dropping an "Empty Box", and typing coil1 above it to let the IDE auto-complete and format the block. - Running a full "Clean All" and rebuilding the code. I am aware that I could bypass the graphical editor by calling it in Structured Text. However, I need to keep this logic compatible to FBD. Has anyone encountered this specific FBD parsing bug with generic variables? Thanks in advance for any insights. Best regards, Marco
Last updated: 2026-06-29

Post by reinier-geers on Ping By Name ^{CODESYS Forge talk (Post)}
How can i ping my computer by name ? My controler uses SysSockPing , But seems only by IP adres, not by name. IP adres changes. So how can i ping by name or know that im connected
Last updated: 2023-08-24

Post by reinier-geers on Ping By Name ^{CODESYS Forge talk (Post)}
To bad. Controller uses Version 9.2 But i dont see a lower version of net bas Service. Maybe i can try a linux command.
Last updated: 2023-08-29

Post by roundex on CSVReaderInit returns error : INVALID_HANDLE ^{CODESYS Forge talk (Post)}
I got same issue but managed to get it to work again by downgrading the Runtime. Here's my specs: CODESYS V3.5.19.0 Runtime Linux SL 4.7.0.0. CSV Utility SL 1.1.0.0 (Licensed IIoT libraries SL) I tried Runtime 4.8.0.0. and 4.9.0.0 but both result in INVALID_HANDLE error.
Last updated: 2023-08-30

Post by janderson on Ethercat scan for devices not picking up EL7041 as a softmotion axis ^{CODESYS Forge talk (Post)}
I have a beckhoff EL7041-1000 rev 21 in my ethercat bus but it wont correctly create a softmotion axis unless i manually insert the device. scan for devices gives me an el7041-1000 without an SM3 axis.
Last updated: 2023-09-02

Post by jinil on Import RsLogix 5000 project to Codesys ^{CODESYS Forge talk (Post)}
Hello, I am trying to do the same thing. I want my Rslogix 5000 project into Codesys. Was wondering if you have found a way to do it. Thank you.
Last updated: 2023-09-07

Post by jinil on Import RsLogix 5000 project to Codesys ^{CODESYS Forge talk (Post)}
Hello, I am trying to do the same thing. I want my Rslogix 5000 project into Codesys. Was wondering if you have found a way to do it. Thank you.
Last updated: 2023-09-07

Post by wehling-h on Troubles with using CAN API ^{CODESYS Forge talk (Post)}
Hi together, I'm using a 11bit driver system which seems to work well so far. May someone here knows if i have to configure a singleID for each message i like to receive and evaluate?
Last updated: 2023-09-11

Post by transmin01 on CANbus issue ^{CODESYS Forge talk (Post)}
Hi, I have been trying to get a CANbus device working with Codesys 3.5SP19 patch1 via a Beckhoff EL6751 gateway without success. I have the CANOpen_Manager and CANopen device configured but this will not run. Is there any code required to kickstart the CANbus comms into action? Regards Trevor
Last updated: 2023-09-13

Post by transmin01 on PCAN serial "No CAN driver found" ^{CODESYS Forge talk (Post)}
Second question is, how do I determine the correct network ID for my Canbus config in Codesys? I have 2 CANbus ports on the target PC. Regards Trevor
Last updated: 2023-09-14

Post by derpaul on PFC200 Update to 4.9.0.0 - No Connection ^{CODESYS Forge talk (Post)}
This is: 02.04.22(06) As I do see now, minimal Version is 17, but why did my Controller work with Runtime 4.8.0.0 (Which was the last installed When I remember correctly)
Last updated: 2023-09-28

Post by simond on The required device description is not installed.. ^{CODESYS Forge talk (Post)}
Hi folks, can someone please tell me how to go about fixing this issue? I am getting this error when I implement an instance of the J1939_Manager. Thanks Simon
Last updated: 2023-10-03

Post by tomas111 on Help with error C0142 ^{CODESYS Forge talk (Post)}
There was an exact mistake. I did as they wrote. I created a visualization and transferred it from the old one and everything works. CS 3.5 SP 19. Thank you.
Last updated: 2023-10-04

Post by aott33 on Webvisu NO load ^{CODESYS Forge talk (Post)}
I put in a support ticket request for this issue since I need this application to be running reliably for my customer's application. Hope to hear back from support soon to troubleshoot this process.
Last updated: 2023-10-09

Post by damian177 on MQTT_client disconnect when call MQTT_sunscribe ^{CODESYS Forge talk (Post)}
Probably I have the same problem, When I connect to broker and try subscribe to much topics then the client return error, did you solve your problem ?
Last updated: 2023-10-10

Post by vassilis91 on EtherCat-Rexroth Drive lost connection or no? ^{CODESYS Forge talk (Post)}
Hi all, i am encounter a mystery problem with a build with rexroth drives at my work. At my company we are make a machine with two Rexroth Indradrives . The two drives are goes by ethercat protocol . To be more specific i am going from my plc to the Beckoff El1100 coupler and after to the first drive and from the first drive to the second. The second drive works with no problem but the first(motor) sometimes without any pattern start to make a mysterious noise like stop and suddenly goes on again. If i couldn't hear the noise from the motor i couldn't Imagine that this happen. After a lot of research i see that sometime i have some strange zeros from the drive to the plc? Really i am in a deadlock and I don't know how to continue. From the other side the values on the other drive(second)are stable . The problem maybe: https://youtube.com/shorts/g7PCFLUaDUI?si=eiq0F2IzhQZax2e2
Last updated: 2023-10-25

Post by riccardo on VisuElems.CurrentUserGroupId is not stable ^{CODESYS Forge talk (Post)}
Goodmorning TimvH, Thanks for the reply. I don't know if your solution solve my trouble yet, I am going to see the link you sent me. In the mean time I try to explane better what I need to do. I have a turbine system that get in alarm under some condition (E.g low speed of turbine) and block the itself. When the system is stoped there is no speed turbine and the system cannot start. To give to the operetor the possibility to bypass the alarms, there is an acknoledgement alarm pushbutton. This bypass must not work for everyone but only for those client that perform the login by (User Management). Furthermore, if the user perform the (manual or automatic) logout in alarm conditions, the acknowlegment must be annulled and block the system again. To do this, I need to know if an operator is logged in the page and is working to fix the problem; otherwise the syste must autoturn off again. Now I go to study your solution, if I have explaned better and you have another idea tell me please.
Last updated: 2023-11-16

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