Both SERCOS and EtherCAT Closed Loop Die Accelerators close ther loops around a Setpoint that is one sample old.

When referencing the Die Accelerator, the Die Encoder Position and the Die Setpoint must be modified to match so that there are no motor jumps or thumps. In the case of SERCOS and EtherCAT, both the new and the old (one sample old) must be modified. This was not being done, which caused a motor thump.