[etherlab-users] Arrival of large amounts of data

[Shahbaz Yousefi]

Hi,

Me again, but on a totally different subject.

If you remember, on one of the early emails you said:

> *ecrt_master_receive(master_ptr): Fetches ethernet (yes etherNET!) data
from the card.* This ethernet packet contains all your input domains.

Let's say I have 150 slaves, which with the current configuration, require
the EtherCAT frame to be split in 50 Ethernet frames. Now we checked with
some data sheets and we saw that our network card has a buffer that can hold
64 Ethernet frames.

My question is, what happens if we double the size of our network? If use
300 slaves (that would produce 100 Ethernet frames on each master_send),
wouldn't that overflow the network card's buffer and the data lost?

Or, when the kernel module ec_master is loaded, does that poll the network
card and store the frames in memory? In that case, ecrt_master_receive would
be reading frames from _that_ memory instead of the card itself.

Shahbaz
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