[etherlab-dev] DC synchronous question

[COOKIY]

Hello everyone:
    First, thanks for browsing.Now, we use open-source EtherCAT master to control my robot which is a 6 DOF arms.Everything is ok except the DC synchronous question, while the DC is essential to run in cycle synchronization position mode and I also really don't know the real reason about this and how to handle that question.
    Then,I will depict my question in detials. When run in profile position mode, everything is ok and when it changes to cycle synchronization position mode, I found that it can't to synchronize DC with the errors listing in below:
    [ 1518.043620] EtherCAT ERROR 0-2: AL status message 0x0032: "PLL error".
     [ 1518.043735] EtherCAT 0-2: Acknowledged state SAFEOP.
     [ 1518.055581] EtherCAT ERROR 0-3: AL status message 0x0032: "PLL error".
     [ 1518.055752] EtherCAT 0-3: Acknowledged state SAFEOP.      
     [ 1518.059595] EtherCAT ERROR 0-4: AL status message 0x0032: "PLL error" .
     [ 1518.067537] EtherCAT 0-4: Acknowledged state SAFEOP.
     [ 1518.071643] EtherCAT ERROR 0-5: AL status message 0x0032: "PLL error".
     [ 1518.071862] EtherCAT 0-5: Acknowledged state SAFEOP.     When this errors occurs, the servo drivers change the states from OP state to SAFEOP state. I also ask for this question to beckhoff‘s staff. He said the reason of this question is caused by the CPU jitter and the master of beckhoff corporation could handle this question very well. I really don't understand this meaning very well.
     It is very grateful that if some experts know the ways to handle with this question.Thanks very much!!!!!!!!!
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