Meinberg IMS-GNS181, Руководство по установке

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4 GNSS Receiver
tivated for GPS, then GPS will be used as a measurement reference for all other sources as long as GPS is
available.
If PTP is configured as a secondary priority with "Auto Bias Slave" activated, the constant offset of the PTP
input signal is measured against the current “Auto Bias Master” reference (e.g. GPS) and will be compensated
automatically.
Furthermore, even if PTP becomes a reference signal in case that a Master is not available, the PTP off-
sets will include a compensation for the initial offset measured against the previous Master automatically. In
this operating mode a smooth transition from GPS to PTP will be possible without a time step in case GPS
becomes unavailable.
If PTP is then a primary sync source and an asymmetry step suddenly occurs in the network (due to path
rearrangements e.g.), the occurring asymmetry step will therefore be automatically compensated as well in case
"Asymmetry Step Detection" is activated.
Asymmetry Step Detection
When Asymmetry Step Detection is activated, the PTP slave does not follow hard time jumps. The soft syn-
chronization is retained and the time jump is displayed as an offset in the MRS statistics.
With activated "Asymmetry Step Detection", the system measures the offset for approx. 10 minutes. After
another 10 minutes, a determined value or offset is set, which is then displayed under MRS -> PTP status
[Step Compensated]:
Auto-Bias: 0.000000000s
Step-Comp.: -0.000010001s
Span: 0.000000025s
IMS-GNS181 Setup Guide Date: 20th March 2020 15