Modbus TCP failed connection

[Dinko]

        Hi guys,

I connected  Vision V350 TU24 PLC  to Weintek HMI via MODBUS TCP just to check the communication and which commands for read and write are working.  Everything was working perfect, but I made small  experiment- I removed the cable for few seconds and I reconnected it again. The communication was not working good. I had the feeling that the synchronization between both devices was  broken. The communication speed failed down. After I made  reset of the PLC  the communication was restored. The question is can I restart the communication in the software without reset the PLC? In the attachment I send you my test software. If you have any ideas, you can correct it.

Thanks in advance and Have a good day.

MODBUS_IP.vlp

[Flex727]

Try setting a Power-Up value of about 10 in SI 105.

[Joe Tauser]

Here's how I do it -

 

Just set an MB (MB 215 in this example) to re-trigger the CARD INIT block.  This is super handy if you have a screen to set the IP address, or if the Ethernet port gets stuck as in your case.

Note that if you're online via Ethernet and trigger this logic you WILL lose communication.

 

Joe T.

[Fernando Castro]

You need to do the logic to re connect, as the colleagues pointed out there are some system bits to track the socket status.