arctinet Posted March 11, 2021 Report Share Posted March 11, 2021 Hi All, I'm battling a bit with modbus TCP multiplexing and missing messages. I have a Vision 430 with 5 VFD's. Some of the time, the messages go through quite fine. I send a PHR, the action is taken and the MODBUS status message is 0 - all good. Some of the time, I send a PHR, the action is taken but the status message shows as 4, then 5(timeout) but the VFD still receives the message and carries it out. Sometimes I send a PHR and nothing happens. Does anyone have an example of a successfully completed modbus TCP multiplexing that I can take a look at? Or perhaps any tips as to where I can look. My code looks a lot like the V280 Example with the exception of a connect at the beginning of each command and a disconnect after - sample attached. Many thanks! AF Example.vlp Quote Link to comment Share on other sites More sharing options...
MVP 2023 Flex727 Posted March 13, 2021 MVP 2023 Report Share Posted March 13, 2021 I haven't looked at your code yet, but I presume you are connecting and disconnecting for each VFD communication. If so, you need to provide surprisingly long wait times between each operation - on the order of at least a couple of seconds, if not more. If the total cycle time becomes too long for your application, you can connect to 2 or 3 at a time since you have 4 sockets available. A better option would be to use the V700, since it has 8 sockets, so that you can maintain communication with all 5 simultaneously and continuously. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.