Burkert Type 8620 - Manual (Page 42)

mxCONTROL Type 8620
Page 42
11.3.1 Selection of SD card size for Data Logging
purposes
The size required for one process data sample depends on the current configuration and the sample
time. Every Tsample seconds a new sample of process data is written into the internal volatile Data
Logging memory.
Required free memory
in [kByte]
( ) ( )
kByte 1024 HeaderData NOC SampleData Days LogsPerDay + ∗ + ∗ ∗ =
with
LogsPerDay
NOE
Tsample
s +
=
86400
NOE “Number Of trigger Events per day” which forces a new
process data sample to be written.
For trigger events refer to above section “Event
Triggered Data Logging Function”.
Tsample Data Logging Sample Time in seconds
Days Number of Days to be logged
SampleData See below
NOC "Number Of Changes": Number of events requiring a
new "header" in the data log file
HeaderData See below
86400 s = 24 h = 1 day
Required free memory
in [MByte] = Required free memory
in [kByte]
kByte 1024
MByte 1
∗
It is:
SampleData - storage capacity required on the SD card to log 1 process data sample after Tsample
has run down and
HeaderData - storage capacity required on the SD card to log 1 header + 1 process data sample.
That means, a new header and a current process data sample is written each time, when:
• enabling the Data Logging
or if Data Logging already is enabled:
• returning to the Main Menu after configuration and/or parameter were changed
• the download is finished successfully / is cancelled / failed
SampleData in [kByte] = 0.05 kB
*
(2 + Number of modules)
HeaderData in [kByte] = 0.4 kB
*
(1.5 + Number of modules) + SampleData
with Number of modules: Number of active modules.