Hello All:
I'm a newbie for Arduino platform. I'm currently trying to establish a connection between Arduino Mega and RedLion HMI using MODBUS TCP. I've Arduino Ethernet shield which is assigned with a IP address. I am trying to capture Arduino data on WireShark. But, not able to see any packets being transmitted on Wireshark. Does anyone have any idea??
Thanks,
Shwetha.
Your problem is due to your network setup. If you are using an ethernet switch to connect your PC, Arduino Mega, and RedLion HMI then each one is hanging off its own port. An intelligent switch will restrict port-to-port traffic so not all ports can see all ethernet packets.
For example let's assume you have the Arduino on port 1, RedLion on port 2, and your PC (Wireshark) on port 3. If the Arduino makes a request to talk with the RedLion then the switch will intelligently route all packets from port 1 to port 2 (and back again) without ever sending a single packet to port 3.
There are a couple of ways to solve this. The first is to try and find a dumb hub/switch which will route all packets to all ports. The second option is to configure your intelligent switch to send all the packets to port 3. It's a feature that is usually reserved for more expensive intelligent switches.
Thank you for the help. I'll try that.