Hallo, hat hier schon mal jemand einen Siemens V20 Frequenzumrichter in Codesys mit Modbus RTU gesteuert? ^{CODESYS Forge talk (Thread)}
Hallo, hat hier schon mal jemand einen Siemens V20 Frequenzumrichter in Codesys mit Modbus RTU gesteuert?
Last updated: 2022-12-22

Hallo, hat hier schon mal jemand einen Siemens V20 Frequenzumrichter in Codesys mit Modbus RTU gesteuert? ^{CODESYS Forge talk (Thread)}
Hallo, hat hier schon mal jemand einen Siemens V20 Frequenzumrichter in Codesys mit Modbus RTU gesteuert?
Last updated: 2022-12-22

How can I convert a 2 word modbus address to real? ^{CODESYS Forge talk (Thread)}
How can I convert a 2 word modbus address to real?
Last updated: 2014-11-22

How do you change the 'read offset' of a Modbus channel on the fly? ^{CODESYS Forge talk (Thread)}
How do you change the 'read offset' of a Modbus channel on the fly?
Last updated: 2021-04-14

Write float value in modbus register and Read value whit comma from codesys ^{CODESYS Forge talk (Thread)}
Write float value in modbus register and Read value whit comma from codesys
Last updated: 2018-05-28

What is the equivalent in codesys of Modbus M flag? ^{CODESYS Forge talk (Thread)}
What is the equivalent in codesys of Modbus M flag?
Last updated: 2011-12-02

OPTO22 Groov Epic PR2 Modbus Comms Dropping out every 2 hours and 4 Mins ^{CODESYS Forge talk (Thread)}
OPTO22 Groov Epic PR2 Modbus Comms Dropping out every 2 hours and 4 Mins
Last updated: 2024-04-15

OPTO22 Groov Epic PR2 Modbus Comms Dropping out every 2 hours and 4 Mins ^{CODESYS Forge talk (Thread)}
OPTO22 Groov Epic PR2 Modbus Comms Dropping out every 2 hours and 4 Mins
Last updated: 2024-04-15

Assigning Modbus addresses to a structure in a dynamic way ^{CODESYS Forge talk (Thread)}
Assigning Modbus addresses to a structure in a dynamic way
Last updated: 2025-10-21

Has anyone fed ESP32 sensor data into CODESYS (via MQTT/Modbus)? ^{CODESYS Forge talk (Thread)}
Has anyone fed ESP32 sensor data into CODESYS (via MQTT/Modbus)?
Last updated: 2025-10-29

Post by timvh on runtime dynamic modbus devices ^{CODESYS Forge talk (Post)}
Maybe the ModbusFB library is a good option for you. See: https://forge.codesys.com/prj/codesys-example/modbus/home/Home/
Last updated: 2025-11-21

Post by struccc on Problem Reading Registers via Modbus from non Codesys device ^{CODESYS Forge talk (Post)}
Hi, Might be a good idea first to try out the connection and the device with some handy software, like Modbus Poll. There you can see better, what's really going on... - Is it really connected? - What error code does it return? - Can it read from the register address? - Maybe try Input registers and Holding Registers - can make a difference - Sometimes register addresses are messed up: shifted +-1 (mixing of 2 standards) - Sometimes register addresses start with offset 30000, 40000 ... - Are you using the right protocol? - Is it RTU or TCP? Maybe ASCII? - Can even have a look at the data packets, etc... All this is easier to figure out first with some modbus utility... and then to set it up in CODESYS should not be an issue. P.
Last updated: 2025-03-09

Post by elsmart on Sequential read and triggering of Modbs RTU channels in application ^{CODESYS Forge talk (Post)}
Hello I need some help understanding how to use Modbus RTU (COM port) in Codesys enviroment. I defined a Modbus Server device (slave) in device tree and added some channels to read from (function 3). Also I set trigering mode to Application. I have a POU in which I want to trigger each channel one after the other something like this (C code for better visualisation): for (int i = 0; i < channelsCount; i++) { triggerChannel(channelsArray[i]); // Start transmission while(channel.xBusy); // Wait for transmission to complete } I have found ModbusChannel function block documentation but examples are scarce. I don't understand how rising edge triggering works. What would be the best solution for achieving sequntial channel triggering? What is the common way to read multiple Modbus channels once every time a specified POU is executed?
Last updated: 2025-05-16

Post by mbmik on IoDrvModbusTCP_Diag not defined when using MODBUS ^{CODESYS Forge talk (Post)}
Hi Im trying to setup a Weidmüller WL2000 to run with MODBUS, to get some data from a server. Codesys V3.5 SP20. The issue is, that whenever i attach an ethernet port and add MODBUS Master und also a Slave, codesys will compile the project, but there always seem to be some remaining errors, which or only visible, when setting the messages window to "Pre-Compiled". I tried a lot of stuff to get rid of these errors, but cant find to seem the reason. New installation of codesys, cleaned project, setup completely empty new project, manually adding libs. Nothing helps. Any help is apreciated. Maybe we are doing something wrong.. Example Project is available, if somebodey wants to take a look. Greetings and thanks alot
Last updated: 2024-04-15

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 ahuckphin on Issues with Modbus Slave with Raspberry Pi ^{CODESYS Forge talk (Post)}
I have a DFRobot RS485 temperature & humidity sensor (SEN0438) connected to my Raspberry Pi via a USB to RS485 adapter. I am able to connect and read the sensor data when running a python code locally. However in Codesys, I encounter this error "A bus error has occurred." and "There was no response in time". Could this be because of Modbus Server Channel and Modbus Server Init configuration on my part? Admittedly I am new to Codesys. To get to this stage, I: 1. added some lines to CODESYSControl_User.cfg 2. added "Modbus_COM" in Codesys and set "Serial Port Configuration" under "General" 3. added "Modbus_Master_COM_Port" in Codesys and checked transmission mode is set to "RTU" 4. added "Modbus_Slave_COM_Port" in Codesys and checked server address is set to 1 (also set 1 in my sensor) 5. added 1 channel and 1 init for "Modbus_Slave_COM_Port" under "Modbus Server Channel" and "Modbus Server Init"
Last updated: 2024-07-10

Post by george32 on TCP Server ^{CODESYS Forge talk (Post)}
Dear people, I would like to create a TCP server in my PLC program. The TCP server needs to communicate with an external device. I have been searching the internet and found that the libraries Syssocket or CAA NetBaseSrv are two possible solutions to create a TCP server. From what I have read, CAA NetBaseSrv is more user-friendly to implement than the Syssocket variant. However, I am still struggling to actually implement this library. Foremost is my little knowledge about creating a TCP server and how to read/understand each function block, especially the outputs of some blocks and the types, e.g. server has an output CAA.Handle, but I cannot find the explanation of CAA.Handle. I tried to find a good document that can help me understand how to implement a TCP server, but I could not find it. Thank you in advance, George
Last updated: 2025-02-20

Post by tk096 on gear over gear (2 masters,1 slave) - how to do it? ^{CODESYS Forge talk (Post)}
Hi, you could calculate the position/dynamics of the slave axis yourself and use one of the function blocks SMC_FollowPosition/SMC_FollowSetValues to move the slave axis. https://content.helpme-codesys.com/en/libs/SM3_Basic/Current/SM3_Basic/POUs/Movement/Direct/SMC_FollowPosition.html https://content.helpme-codesys.com/en/libs/SM3_Basic/Current/SM3_Basic/POUs/Movement/Direct/SMC_FollowSetValues.html
Last updated: 2024-08-19

Post by ph0010421 on TCP/IP client ^{CODESYS Forge talk (Post)}
Hello Use 'Import PLCOpenXML' to bring this into your project.
Last updated: 2023-12-20

Post by eschwellinger on Ethercat Slave - Load PDO From Device ^{CODESYS Forge talk (Post)}
Which CODESYS Version and which EtherCAT Master version?
Last updated: 2024-10-23

Post by boehli on canOPEN ^{CODESYS Forge talk (Post)}
Hallo, gibt einen codesys Treiber oder Unterstützung für Hilscher canOPEN Slave oder Master Karten?
Last updated: 2024-05-15

Post by boehli on canOPEN ^{CODESYS Forge talk (Post)}
Hallo, gibt einen codesys Treiber oder Unterstützung für Hilscher canOPEN Slave oder Master Karten?
Last updated: 2024-05-15

Post by dkugler on Generic EtherCAT slave ^{CODESYS Forge talk (Post)}
@xiaonyan: open new topic please!
Last updated: 2024-05-17

Post by rafa on MODBUS TCP SERVER DONT AUTO-STARTUP ^{CODESYS Forge talk (Post)}
Dear all, I have a project where I have two ModbusTCP communication drivers in the application. It's working normally until a power outage or the installation panel is restarted. As soon as the PLC CPU is restarted, the Ethernet port is OK, but the TCP Server displays an "UNDEFINED" error. I can't reset the error using the diagnostic confirmation or the "mbserver.xConfirmError" bit. I noticed that the error only appears in the "mbserver.byModbusError" memory and the description is "UNDEFINED." The "mbserver.xError" memory doesn't flag an error. When using the warm restart function and then START CPU, the devices return to normal operation. The following demonstration images; The main question is: How can I make devices boot automatically?
Last updated: 2025-07-15

Post by rafa on MODBUS TCP SERVER DON'T AUTOMATIC STARTUP ^{CODESYS Forge talk (Post)}
Dear all, I have a project where I have two ModbusTCP communication drivers in the application. It's working normally until a power outage or the installation panel is restarted. As soon as the PLC CPU is restarted, the Ethernet port is OK, but the TCP Server displays an "UNDEFINED" error. I can't reset the error using the diagnostic confirmation or the "mbserver.xConfirmError" bit. I noticed that the error only appears in the "mbserver.byModbusError" memory and the description is "UNDEFINED." The "mbserver.xError" memory doesn't flag an error. When using the warm restart function and then START CPU, the devices return to normal operation. The following demonstration images; The main question is: How can I make devices boot automatically? Um using Codesys Version 3.5.20.30 Patch 3+ My CPU is a Weintek Cmtx Built-int - ( CMT3092x )
Last updated: 2025-07-15

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