Struct DistributedClock 

pub struct DistributedClock { /* private fields */ }

implementation of the Distributed Clock (DC) at the master level.

The time offsets and delays measured by this clock synchronization mode are shows in the following chronogram for one packet sending.

Implementations

impl DistributedClock

pub async fn new( master: Arc<RawMaster>, delays_samples: Option<usize>, offsets_samples: Option<usize>, ) -> EthercatResult<Self>

initialize the distributed clock on the ethercat segment

Since the slaves responsibilities in the distributed clock only depend from the topology of the network, this initializer will automatically detect the topology and act accordingly

parameters

• delays_samples: number of clock sampling used in estimating the propagation delays between slaves (defaults to 8)
• offsets_samples: number of clock sampling used in estimating the offsets between slaves clocks (defaults to 15_000)

pub fn referent(&self) -> SlaveAddress

getters return the slave address of the slave used as reference clock. This slave is called referent, or reference slave.

pub fn system(&self) -> i128

return the (estimated) current time on the reference clock

pub fn epoch(&self) -> i128

offset between the ethercat system clock (arbitrarily zeroed) and unix epoch. In this implementation, the ethercat system clock zero is when this struct is initialized

pub fn offset(&self, slave: SlaveAddress) -> i128

time offset from given slave clock to the reference clock

pub fn delay(&self, slave: SlaveAddress) -> i128

return the transmission delay from the reference slave to the given slave

pub fn offset_master(&self) -> i128

time offset from the reference clock to the master clock

pub fn delay_master(&self) -> i128

return the transmission delay from the master to the reference slave

pub async fn sync(&self)

distributed clock synchronisation step. It must be called periodically to save the distributed clock from divergence

pub async fn sync_loop(&self, period: Duration)

distributed clock synchronisation task. Using cycle time as execution period

Once the automatic control is start, time cannot period cannot be changed. Start cyclic time correction only with conitnuous drift flag set.

One task only should run this function at the same time. It will be calling Self::sync