Hardware properties
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8.1
Timestamp
The figure hereafter shows for „Ethernet Mode“ or for „Transparent Mode“,
where the timestamp for the associated data packet is taken.
Figure 24: Ethernet frame timestamp-point for „Ethernet Mode“ and „Transparent Mode“
„DV“ = Data Valid, „D0..3“ = Data, „5 d“ = SFD identifier
„SFD“ = Start-of-Frame-Delimiter
„Ethernet Mode“ (Standard Capturing):
In „Ethernet Mode“ the time stamp is taken at the reception of the SFD
(Start-of-Frame-Delimiter).
„Transparent Mode“ (SFD is disturbed):
In „Transparent Mode“ the time stamp is always taken at the very front with
the "data valid" lateral growth, i. e. at the proper start of the Ethernet
frames. This makes it possible to find a reference point also for faulty
frames. Thereby the preamble and SFD are not interpreted.
Accuracy of the time stamping
Time stamps on port 0 and port 1 on the NANL-B500G-RE device can have
an offset of up to 40 ns. After a settling time of approx. 100 ms from
reception of the first frame on a port, the offset on this port is max. 8 ns.
Time stamps on port 2 and port 3 on the NANL-B500G-RE device have
always a max. offset of 8 ns, without settling.
netANALYZER device NANL-B500G-RE | Installation, operation and hardware description
DOC091110UM26EN | Revision 26 | English | 2019-07 | Released | Public
© Hilscher 2007-2019
