Guralp Systems CMG-CD24 User Manual
Page 58
CMG-CD24
This setting will be overridden when the GPS system next
synchronizes the clock.
5.3.6 TIME?
Syntax: TIME?
Displays the current time as held in the system's real time clock. If a
GPS is attached, this will be synchronized to it. The output is given in
the form
year month day hour:minute:second ok
5.3.7 LEAPSECOND
Syntax: yyyy mm dd LEAPSECOND
Manually notify the digitiser of an upcoming leap second. This
command is not normally necessary, since GPS already has support for
leap seconds. However, some units do not properly interpret the GPS
signals. See SQPATCH, below.
The leap second is taken to be at the end of the day yyyy-mm-dd.
5.3.8 SQPATCH
Syntax: SQPATCH ENABLE | SQPATCH DISABLE
Enables or disables the internal patch for older GPS receivers based on
Trimble Lassen SQ units. These units misinterpret the GPS system's
advance notification of a leap second, and consequently run one
second slow until the leap second occurs.
With SQPATCH enabled, the time reported by the digitiser is offset by
one second to counteract this problem. If you have set LEAPSECOND,
above, SQPATCH will automatically be disabled when the leap second
occurs, and the digitiser will then run normally.
GPS receivers with the latest firmware do not suffer from this problem.
To find out whether SQPATCH is currently enabled, issue the
command .SQPATCH
58
Issue C