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Calibir GXM640 IR Camera User's Manual
Operational Reference
115
Overview of Precision Time Protocol Mode (IEEE 1588)
PTP Mode = Precision Time Protocol
The PTP protocol synchronizes the Timestamp clocks of multiple devices connected
via a switch on the same network, where the switch supports forwarding of PTP
messages.
For optimal clock synchronization the imaging network should use one Ethernet
switch. Daisy-chaining multiple small switches will degrade camera clock syncs.
Calibir cameras can automatically organize themselves into a master-slave hierarchy,
or the user application configures a camera master with n-number of slaves.
The automatic organizing procedure is composed of steps (as defined by IEEE 1588)
to identify the best clock source to act as master. When only Calibir cameras are
used, since they are equal, the last selection step is to identify the Calibir with lowest
value MAC address to be the clock master.
The feature TimeStampSource is automatically changed to IEEE1588 when PTP Mode
is enabled.
The Calibir cameras implement additional features designed to synchronize multiple
camera acquisitions via IEEE 1588 (PTP Mode) – for example using timestamp modulo
events, not via external camera trigger signals.
PTP Master Clock Identity
The clock ID of the current best master is an Extended Unique Identifier (EUI)-64 “64-
bit ID”, converted from the 48-bit MAC address, by inserting 0xfffe at the middle of the
MAC address.
The standard MAC address in human-friendly form is six groups of two hexadecimal
digits as this example shows (excluding hyphens ): “0a-1b-2c-3d-4e-5f”
The Extended Unique Identifier format is (excluding hyphens): “0a-1b-2c-ff-fe-3d-
4e-5f”
