Elgas EDT 101, User Manual

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4.5.5 Synchronize datalogging (46h)
The transducer is able to automatically measure temperature in preset time intervals and
store the values into the registers 40088 - 40167 (datalogging). Synchronize Datalogging
command can be used to start or re-synchronize the datalogging.
The query specifies Period parameter which describe measurement timing. If no datalogging
is in progress, the Synchronize Datalogging command starts it. The first temperature
measurement is initiated immediately after receiving the query. The next measurements are
then initiated in regular intervals defined by the Period value.
If datalogging is already in progress, the Synchronize Datalogging command re-synchronize
the internal time base. The oncoming measurement is expedited in order to start immediately
after receiving the query. The next measurements are again initiated in regular intervals
defined by Period value. Figure 7 illustrates using of the Synchronize Datalogging command.
Query
Period Period Period
Sample
1
Sample
4
Sample
2
Sample
5
Sample
3
Query Response Response
Synchronize
datalogging Synchronize
datalogging
Communication
Measurement
time
Figure 7. Using of Synchronize datalogging command.
Bit 1 (Datalogging in progress) in the Status register is set during datalogging. When the data
memory is full, measurement continues, but no values are stored, bit 11 (Data memory
overflow) in the Status register is set. Datalogging resumes after the memory is erased by the
Erase data command (see paragraph
Chyba! Nenalezen zdroj odkazů. ) If the Period parameter
is set too short with respect to the time of measurement, the measurements are initiated as
fast as possible and bit 12 (Timing error) in the Status register is set to indicate error.
Value of the Period parameters can be calculated using formula:
Period = 128. t -1,
where t is time of the period in seconds.
The period value can be also set anywhere from 1/128 s to 512 s (0000h to FFFFh) with
resolution of 1/128 s, but the period should be longer than time of the measurement 125 ms.
Datalogging can be stopped at any moment by Stop measurement function, see chapter 4.4.5.