对,不可能是每个周期。有这么一段话
For static drift compensation, themastersends many separate ARMW or FRMW drift compensation frames (e.g., 15,000 frames) to distribute the System Time of the Reverence Clock to all DC slaves.
For dynamic drift compensation, themastersends ARMW or FRMW commands periodically to distribute the System Time of the Reverence Clock to all DC slaves. The rate of the drift compensation commands depends on the acceptable maximum deviation.