Bad news is im still not able to communicate with my controller, and i think it is the adressing and the data fields in control builder that is causing the trouble, the LED for TX on the controller is blinking, but there is no response from the slave, still have the same error code timout no response from slave.
The good news is that i have managed to connect to my slave device in 2 different ways, using software from my computer and using a modbus library on my arduino uno card. According to the modbus memory map of my slave device function 04 is read input registers, attached as picture. I was hoping there was only something wrong with my adressing, so i will try some of the software you mentioned and see if that works. I gues it was a poor choice of words : The converters i am using is in the cheaper range so it might be something wrong with the physical connection. If you understand the modbus message protocol you can also send Modbus requests to the slave using Hyperterm or PuTTY, but its obviously much easier to use a modbus tester. You should see the PM sending requests to the slave. Check the configuration of the cable or use the ACM programming cable. Re-check all your settings like slave identity, adresses, speed, parity, baud rate etc. So either the slave is ignoring your request for data, eg wrong slave identity or theres a physical fault eg broken cable. Which means you get a different error code on the MBRead. If you send the slave a bad address 'IW04 30xxx'. The Status Code is telling you that the slave is not repsonding at all. It is NOT telling you that the complete link to the device is tested and working. So the MBConnect block is simply telling you that the connection in the PM is configured correctly. If the poll time is set to zero, then the Modbus device is not "polled" - or checked to see if it is there - by the MBConnect Block. If you got the answer then vote for appropriate answer and help in closing this thread.Īdd new comment. I have checked the settings, and they are the same on both master and slave, poll time is set to zero. But i am having no success, i get the same error codes when i try to write registers 'QX06 40xxx'. Jan 16,At the moment im just trying to read some input registers function code 04 and my starting adress is 'IW04 30xxx'. Sep 20, Sep 21, Oct 15, Set theme jekyll-theme-architect. Latest commit db Sep 21, NET - You signed in with another tab or window.
Launching Xcode If nothing happens, download Xcode and try again. Skip to content.ĭismiss Join GitHub today GitHub is home to over 40 million developers working together to host and review code, manage projects, and build software together. Modbus Server Simulator, makes software development fast and easy. NET Industry approved!! Only a few lines of codes are needed to read or write data from or to a PLC.Īdditional Software tools e. If nothing happens, download the GitHub extension for Visual Studio and try again. If nothing happens, download Xcode and try again. If nothing happens, download GitHub Desktop and try again. I can’t figure out if there is something wrong on the configuration, on the C program or on the expectations.GitHub is home to over 40 million developers working together to host and review code, manage projects, and build software together. (I can’t include a screenshot because new users are allowed to send only one image) With Wireshark I noticed a Malformed Packet Error, but I don’t know if it’s the cause. This is the shortest C program that trigger the error (I’m omitting error checking for brevity). Now I’m trying to send a modbus request through the lib modbus, but then nothing is sent on the RS485 side, and I receive a Connection Reset By Peer error.