Sending the EtherCat cyclical frame needed to be seperated from the local encoder feedback capture and loop calculation. We needed to provide a larger safety margin for when to send the frame, while also trying our best to syncronize the EtherCat feedback capture with the XL local capture. More detail can be found in the Design_EC_Frame_Scheduling.md document in source control.

The symptoms of the issue were random negative, followed by immediate positive spikes in the CL Data feedback. This was caused by randomly getting old feedback for one sample that would catch up on the follwing sample.

While testing, we discovered an unexplained 100usec positive jitter that was eventaully tracked down to a 1024 byte mailbox size on the ctrlX. This is three times larger than the Indradrive. The full mailbox must be read. This equates to ~100usec on the bus vs ~25usec that the Indradrive has. While reserching, we implemented an errata fix on the NIC that was not provent to be required.