Multi-Tech Systems 7500 ユーザーズマニュアル

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ION 7500 / ION 7600 User’s Guide
Diagnostics and Event Logging
Time Synchronization & Timekeeping Technical Note
Page 355
Diagnostics and Event Logging
The meter’s Diagnostics module includes output registers that provide time 
synchronization diagnostics. Events are logged by the meter’s Clock module, 
Communications modules, and Diagnostics module in response to time 
synchronization events.
Diagnostics Module Output Registers
Time Sync Source 
This register is 
ON
 if the internal clock synchronizes with the line frequency or 
GPS, and it is 
OFF
 if the internal clock synchronizes with its own internal crystal.
GPS Receiver Status
This register is 
ON
 if the GPS receiver is locked onto a time source and 
OFF
 if the 
lock is lost. This information is received directly from the GPS receiver; the 
register is 
NOT
 
AVAILABLE
 if the GPS time synchronization is not used.
Time Sync Count
This register indicates how many time synchronization signals have been 
received. The value increases with each signal received.
Time Since Last Time Sync
This register displays the amount of time, in seconds, since the last time 
synchronization signal was received.
Time Sync Diag (time sync diagnostics)
This register displays the difference, in microseconds, between the timestamp 
in a synchronization signal and the time in the device’s clock when the signal is 
received. The displayed value is a sliding window average over the last five 
time synchronization signals received.
Time Sync Status
This register is 
ON
 if a time synchronization signal is acquired, and 
OFF
 if the 
signal has been lost. The Diagnostics module calculates the average interval for 
the last five signals received, considering the signal lost if no signals are 
received in two times the average interval.
Event Logging
The following events appear in the Event Log:
Time sync acquired — generated when the first time sync signal is received 
(Diagnostics module’s Time Sync Status register goes 
ON
).
Time sync lost event — generated if no time sync signals are received in two 
times the average interval of the last five signals (Diagnostics module’s Time 
Sync Status register goes 
OFF
).
GPS locked — generated when the GPS receiver locks onto a time source 
(Diagnostics module’s GPS Status register goes 
ON
).