Rainbow Electronics DS2422 - Manual (Page 23)

DS2422
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lower address. Knowing the starting time point (Mission Time Stamp) and the interval between temperature
measurements one can reconstruct the time and date of each measurement.
There are two alternatives to the way the DS2422 behaves after the datalog memory is filled with data. The user
can program the device to either stop any further recording (disable “rollover”) or overwrite the previously recorded
data (enable “rollover”), one entry at a time, starting again at the beginning of the respective memory section. The
contents of the Mission Samples Counter in conjunction with the sample rate and the Mission Time Stamp will then
allow reconstructing the time points of all values stored in the datalog memory. This gives the exact history over
time for the most recent measurements taken. Earlier measurements cannot be reconstructed.
Figure 10A. One-Channel Logging
8192
8-bit entries
Temperature
or
External data
4096
16-bit entries
Temperature
or
External data
1000h
2FFFh
1000h
2FFFh
ETL = 1; EDL = 0 or
ETL = 0; EDL = 1
TLFS = DLFS = 0
ETL = 1; EDL = 0 or
ETL = 0; EDL = 1
TLFS = DLFS = 1
With 16-bit format,
the most-significant
byte is stored at the
lower address.
Figure 10B. Two-Channel Logging, Equal Resolution
Temperature
4096
8-bit entries
External Data
4096
8-bit entries
Temperature
2048
16-bit entries
External Data
2048
16-bit entries
1FFFh
2000h
1000h
2FFFh
1FFFh
2000h
1000h
2FFFh
ETL = EDL = 1
TLFS = DLFS = 0
ETL = EDL = 1
TLFS = DLFS = 1
With 16-bit format,
the most-significant
byte is stored at the
lower address.