Larson Davis System 824, Справочное руководство

Страница: 443 / 536

9/12/00 B -45
History Records
Histories are records of stored data based on time or a partic-
ular event. One record is available at a time. The current
record number is selected by using the Advance, Backup,
and Find commands (see below) or the Setting S211 through
S217.
The various histories of the System 824 are each accessed in
a similar fashion. The Find command is the primary method
of locating a history record for random (nonsequential)
access. For example, to find the one hundred twenty-fifth
Exceedance record you send the command F125,1 <cr>
where the [,1] specifies that it is an Exceedance record to be
found (as defined in the “history_number” column below).
The Advance and Backup commands are generally used
next. They extract data after the initial find command.
The Find command takes longer to execute as the record
number increases in size, therefore, for sequential data
extraction locate the first desired record with the Find com-
mand and then use the Advance command. The
[,relative_rec] option can be used to retrieve data forward or
backward from the current record number without changing
S199 RTA Event ByTime REPORT LOWEST
RECORD nnnnn
S200 RTA Event ByTime REPORT HIGHEST
RECORD nnnnn
S213 RTA ByTime History Record (nnnnn)
S195 RTA Spatial Average History Report Enable
S201 RTA Temporary Note Field for Spatial Aver-
age
S139 RTA FFT Repeat on Count complete [0 =
No, 1 = Yes]
S138 RTA FFT Enable Overload Skipping [0 =
No, 1 = Yes]