PRISM MPI2-25 and MPX2-25 Media Analysis Platform User Manual
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•
Grandmaster ID
: Shows the MAC Address of PTP Master with the bytes
ff:fe
inserted in the middle. This ID is also used in the BMCA as a tiebreaker when
all of the parameters match down through priority 2.
•
Steps Removed
: Shows the number of communication paths traversed between
the local clock and the Grandmaster clock.
•
Domain
: Shows the domain being used. Domains allow multiple PTP services
to coexist simultaneously on one physical Ethernet connection.
•
Profile
: Shows the profile being used: General, AES67, or ST2059. This is the
user-selected profile set on the Settings > Reference configuration menu page
and is not detected on the input.
•
Delay Message Interval
: For Multicast communication mode, the only delay
message interval allowed is "Follow Master". In this mode, the slave will set
the delay request rate according to the information sent by the master in the
delay response message.
NOTE.
The PRISM monitor currently supports Multicast communication mode and
SMPTE mixed mode without negotiation. In later firmware releases, other
communication modes will be supported.
•
Grandmaster BCMA Values
: Lists these values for the Grandmaster BCMA
(Best Master Clock Algorithm) in order of precedence:
o
Priority 1
: This parameter defines which clocks are allowed to be
considered as masters. To be considered as a master, the value should be
set to 128 or less. Priority 1 is the first criteria in the BMCA, so if Priority
1 is set to a lower value than other devices on the system, then it will be
chosen even if the clock quality is poor. Typically, all the masters in a
domain should have the same value for the Priority 1 parameter.
o
Clock Class
: This value characterizes the TAI (International Atomic
Time) traceability. The clock class value varies to indicate the type of
reference in use by the Grandmaster clock. For example, when locked to
GPS the PTP grandmaster will report a class 6. However, if in holdover
mode after locking to GPS, then it will report a class of 7.
o
Clock Accuracy
: This value characterizes the clock accuracy for the
purpose of determining the best master clock.
o
Clock Variance
: This value is reported by the PTP master to indicate
the variance of the clock over a one second interval. A lower number
indicates a more stable clock and will be preferred by the BMCA.
o
Priority 2
: This parameter is used to break the tie between masters that
have the same clock quality. Several values may be used to define a
hierarchy of devices. Most profiles use 128 as a default, so a value of 127
or lower would indicate a preferred master.
•
Clock Source
: The clock source field is not used by the BMCA. The field is set
to indicate the type of reference in use by the Grandmaster clock.
