TIDM-DELFINO-ETHERCAT: Distributed Clock mode and Wireshark Capture.

Hello,

my EtherCAT slave device runs in DC mode with 50 us cycle. One variable from the task is linked with variable from the device to establish synchronization.Here is a screenshot from TwinCAT:

So, it is running with 50 us cycle. In the CCS debugger I can see that my Application function runs every 50 us, I can read it from the uC timer.
Next, I fired Wireshark and here is what I can see:

Since I saw that in wireshark I thought that if I set 50 us cycle time it means that EtherCAT frame is sent every 50 us. If we look at the wireshark - they aren't.

So - I would like you to ask about principles:
1. How should I understand 50 us cycle time?
2. Where I can find 50 us value between frames I captured in Wireshark?

Here is one more thing I don't fully understand:

3. Why do I need frames different than LRW? In LRW I have useful data.
4. What exactly Size/Duration means? Is this parameter about sending all   5 commands? If so - is that means that I can set cycle time in DC parameters in about 11 us ?

I appreciate any help. It is hard to fully understand everything from documentation in one attempt. Moreover, I am working on ethercat network for my master thesis and nobody in my facoulty has an experience with EtherCAT. So only people I can ask are you :)

Best Regards,
Dawid.