Larson Davis System 824, Technical Reference Manual

Page: 624 / 673

E-4 824 Reference Manual 9/29/09
Table E-6:
Example LOG Memory Usage Calculation:
Time History Memory Calculation
Line
Resolution Other Level
Bytes per record / Used
16 [1.0dB] [None] 1
17 [0.1dB] [None] 2
18 [1.0dB] [Pk-II|Pk-I |Lmax] 2
19 [0.1dB] [Pk-II|Pk-I |Lmax] 4
20 [1.0dB] [Advc]
1 plus number of
3
(enabled levels)
Calculate
21 [0.1dB]
[Advc]
2 plus 2 times each 3
(enabled levels)
Calculate
A Leq & Max, C
Leq & Max
8
Τ
22 TOTAL bytes / Hist Record
Select the appropriate number of bytes
from lines 16 to 21 above
8
23 Hist Records / Day
24 hours divided by Hist Period in hours
Enter Number Calculated
i.e. 24/(60 sec/3600 sec per hour)=1440
1,440
24
TOTAL
Hist Bytes / Day
Multiply lines 22 & 23 – copy to line 28
11,520
Line
Memory Use per Day Calculation Bytes
25 Exceedance History bytes / day from line 5 18,720
26 Interval History bytes / day from line 11 1,368
27 Daily History bytes / day from line 22 312
28 Time History bytes / day
from line 29 11,520
29 Run Log bytes / day
n = number of Run Log records / day
2
x 20 =
n x 20 bytes/record
40
30 Calibration Log bytes / day
n = number of Cal Log records / day
1
x 17 =
n x 17 bytes/record
17
31 Setup RAM Registers bytes used
n = number of registers stored
0
x 506 =
n x 506 bytes/record
0
32
TOTAL bytes used / day
Sum lines 25 to 31
31,977
33
824's Memory Size
≈
2,000,000 see TOOLS | Memory
Enter total memory shown
2,047,485
34
TOTAL Run Time in days
until out of memory
divide line 38 by line 37
64 days