User manual

Section 7: Buffer: Data Storage and Retrieval Series 3700 System Switch/Multimeter Reference Manual
7-16 3700S-901-01 Rev. C / July 2008
Recall attribute
Description
timestamps
An array (a Lua table) of strings, indicating the time stamp of the
reading formatted in month, day, year, hours, minutes, seconds, and
fractional seconds.
fractionalseconds
An array (a Lua table) of the fractional portion of the time stamps, in
seconds, of when each reading occurred. These are absolute
fractional times.
seconds
An array (a Lua table) of the seconds portion of the time stamp when
the reading was stored, in seconds. These seconds are absolute and
in UTC format.
units
An array (Lua table) of the strings, indicating the unit of measure
stored with readings in the buffer. Units may be designated as one of
the following: „Volts AC‟, „Volts DC‟, „Amps AC‟, „Amps DC‟, „dB VAC‟,
„dB VDC‟, „Ohms 2wire‟, „Ohms 4wire‟, „Ohms ComSide‟, „Fahrenheit‟,
„Kelvin‟, „Celsius‟, „Hertz‟, „Seconds‟, and „Continuity‟.
Example to access recall attributes
To see seconds, fractional seconds, and relative time stamps for entry numbers
2 and 3 in buffer mybuffer2, assuming mybuffer2.collecttimestamps
was set to 1 when the readings were stored
(mybuffer2.collecttimestamps = 1):
printbuffer(2,3, mybuffer2.seconds)
printbuffer(2,3, mybuffer2.fractionalseconds)
printbuffer(2,3, mybuffer2.relativetimestamps)
Time and date values
Time and date values are represented as a number of UTC seconds since 12:00
a.m. Jan. 1, 1970. The os.time() command returns values in this format. Use
os.date() to return values in month, day, year, hours, and minutes format, or
to access the time stamp table. The only exception to this is the use of the
ptpseconds recall attribute, which has the seconds in PTP format.
Buffer status
The buffer reading status attribute can include the status information as a
numeric value shown in the following table. To access status information, send
the following command:
stat_info = readingbuffer.statuses[2]
Buffer status bits