Cpu Drive; Time Keeping; Specifications; Voltage Measurements - Specifications - Campbell CR300 Series Operator's Manual

CR300-Series Datalogger

6.8.2 CPU Drive

6.9

Time Keeping

7.

Specifications

7.1 Voltage Measurements – Specifications
42
When running fast programs or writing to multiple data tables, this normal
function of erasing memory sectors can result in skipped scans.
By default, data storage memory sectors are organized as ring memory. When
the ring is full, oldest data are overwritten by newest data. Using the FillStop
statement sets a program to stop writing to the data table when it is full, and no
more data are stored until the table is reset. To see the total number of records
that can be stored before the oldest data are overwritten, or to reset tables, go to
Station Status | Table Fill Times in your datalogger support software.
The CPU drive contains datalogger programs and other files. It holds a copy of
final-data memory when the TableFile() instruction is used. It provides
memory for FileRead() and FileWrite() operations. This memory is managed
in File Control . When writing to files under program control, take care to
(p. 57)
write infrequently in order to prevent premature failure of serial flash memory.
Measurement of time is an essential function of the CR300. Time measurement
with the onboard clock enables the CR300 to attach time stamps to data,
measure the interval between events, and time the initiation of control
functions. Clock accuracy is ±1 minute per month, with a resolution of 1 ms.
An internal lithium battery backs the clock (see Section 8.3, Internal Lithium
).
Battery
(p. 52)
Voltage measurements use a 24-bit A-to-D converter. One channel at a time is
measured in numeric succession.
Terminals
Differential Configuration:
Single-Ended Configuration:
Ranges:
Accuracy 1,2
0 to 40 °C:
–40 to 70 °C:
Resolution:
Speed:
Input Resistance:
DIFF 1H/1L – 3H/3L
SE 1 - 6
–100 to +2500 mV
–34 to +34 mV
±(0.04% of reading + Offset 3
±(0.1% of reading + Offset 3 )
See TABLE 7-1, Analog Voltage
Measurement Range and Resolution
See TABLE 7-3, Analog Voltage
Measurement Speed
(p. 44)
See TABLE 7-4, Analog Voltage
Measurement Input Resistance and
Current
(p. 44)
)
(p. 43)