7.
Configure Delay Asymmetry
Modify the 'PRIMARY ETH PORT DELAY ASYMMETRY' setting if the delay asymmetry in the network link is
known, otherwise it is recommended that the setting is left as its default value of '0'.
PTP automatically calculates the propagation delay between a server and client, but this calculation assumes
the delay in each direction of transmission is the same. PTP cannot measure and compensate for delay
asymmetry, which means that the presence of delay asymmetry reduces PTP time accuracy.
Delay asymmetry is the server to client path delay minus the client to server path delay. A client uses the
delay asymmetry value to compensate for the error caused by delay in asymmetry in the PTP delay calculation
mechanism.
If the delay asymmetry is known, entering it manually will allow it to be compensated for, and improve time
accuracy. The input range is 3.2768e+14 ns×2
^16
to −3.2768e+14 ns×2
^16
(-5 to 5 seconds).
8.
Configure Advertised Delay Request Interval
The 'ADVERTISED DELAY REQUEST INTERVAL' specifies the time interval between successive Delay
Request messages being sent to other PTP devices on the network. This option only appears when the End to
End Default Profile is selected. This option does not appear when the port is configured as a Forced Client.
By default, this is set to 0 in 2
^n
seconds, or 1 second. The supported range is 0-5 in 2
^n
seconds, or 1-32
seconds.
9.
Configure Announce Interval
The 'ANNOUNCE INTERVAL' specifies the time interval between successive Announce messages being sent
to other PTP devices on the network.
By default, this is set to 1 in 2
^n
seconds, or 2 seconds. The supported range is 0-4 in 2
^n
seconds, or 1-16
seconds.
10.
Announce Receipt Timeout
By default the 'ANNOUNCE RECEIPT TIMEOUT' is set to 3. This means that after 3 announce intervals, if
the device has not recieved an announce message it will trigger an announce receipt timeout event, which will
move the port into a listening state.
11.
Configure Sync Interval
The 'SYNC INTERVAL' specifies the time interval between successive Sync messages being sent to other
PTP devices on the network. This option only appears when a the PTP clock is server capable.
By default, this is set to 1 in 2
^n
seconds, or 2 seconds. The supported range is -1 to 1 in 2
^n
seconds, or 0.5 to
2 seconds.
Provisioning
©
2022 Microchip Technology Inc.
and its subsidiaries
Manual
DS00004572A-page 106
