Fluke 5020A - Manual (Page 66)

5020A
Users Manual
5-30
occur with the North America daylight saving mode if the daily stats record time is 01:00,
since this time will occur twice in one day.
Another effect is with viewing data on a graph in real time. Data is plotted on the graph
sequentially as measurements are made and the graph is scrolled uniformly. No
adjustment is made to the real-time graph when the time changes. However, when a
graph is redrawn (using recorded data, as a result of changing the display layout or
cycling the power) in preparation to resume real-time plotting, the thermo-hygrometer
attempts to accurately plot measurement points at the appropriate time locations. Thus, a
one-hour spring daylight saving time shift will appear as a one-hour gap in the data on the
graph. When a jump backwards is found in the recorded data, such as occurs during the
fall daylight saving time shift, the thermo-hygrometer makes no attempt to plot the data
prior to the time shift; there will appear to be missing data on the left side of the graph.
Graphs drawn using the DATA VIEW function behave similarly when time
discontinuities occur in recorded data. A one-hour jump forward in time causes a one-
hour gap in the data on the graph. However, a one-hour jump backwards in time produces
a graph that also includes the data prior to the time shift. The repeated hour of data is also
plotted but is compressed into one time point, the time just prior to the time shift. In other
words, the data prior to the time shift is plotted first. Then when data for the first hour
after the one-hour shift backwards is encountered, the data is plotted as if it all occurred
at the instant of the time change. Then when the hour's data has passed, plotting resumes
normally and the data is plotted to the right of the time shift.
Note that in any case data is recorded to memory as would be expected, with a one hour
time gap or a repeated hour when a daylight saving time shift occurs. The effects of the
automatic daylight saving time shifts should cause minimal inconvenience, as they occur
early Sunday morning. To prevent confusion and time ambiguity problems, avoid
running environment-sensitive operations during the daylight saving time shift. Also
consider temporarily suspending data recording for days on which daylight saving time
shifts occur. But if you do this, be sure to resume data recording when you need it!
The A D buttons are used to select the menu parameter. The B C buttons are used to
change the parameters. Press the E button to save the new setting. Press the F button
to cancel any changes and exit to the menu.
Comm Setting
The COMM SETTING function is used to setup the communication parameters for the
communication ports. Communications ports are used for communicating with a
computer, printer, or other equipment. The thermo-hygrometer includes a serial (RS-232)
port and IR port. To edit the settings for a specific port it must first be selected. The
selections are SERIAL, IR, and ERRORS.
The ERRORS setting allows the user to view any error messages stored in the error
queue. Once an error has been viewed, it is removed from the error queue.