Campbell Scientific CR23X Micrologger - Manual (Page 31)

CR23X MICROLOGGER OVERVIEW
OV-21
OV6. DATA RETRIEVAL OPTIONS
There are several options for data storage and
retrieval. These options are covered in detail in
Sections 2, 4, and 5. Figure OV6.1-1
summarizes the various possible methods.
Regardless of the method used, there are three
general approaches to retrieving data from a
datalogger.
1) On-line output of Final Storage data to a
peripheral storage device. On a regular
schedule, that storage device is either
"milked" of its data or is brought back to the
office/lab where the data is transferred to
the computer. In the latter case, a "fresh"
storage device is usually left in the field
when the full one is taken so that data
collection can continue uninterrupted.
2) Bring a storage device to the datalogger
and milk all the data that has accumulated
in Final Storage since the last visit.
3) Retrieve the data over some form of
telecommunications link, whether it be RF,
telephone, cellular phone, short haul
modem, or satellite. This can be performed
under program control or by regularly
scheduled polling of the dataloggers.
Campbell Scientific's Datalogger Support
Software automates this process.
Regardless of which method is used, the
retrieval of data from the datalogger does NOT
erase those data from Final Storage. The data
remain in the ring memory until:
They are written over by new data (Section 2.1)
Memory is reallocated or the CR23X is reset
(Section 1.5)
Table OV6.1-1 lists the instructions used with
the various methods of data retrieval.
TABLE OV6.1-1. Data Retrieval Methods and Related Instructions
Method Instruction/Mode Section in Manual
Storage Module Instruction 96 4.1, 12
8
4.2
9
4.5
Telecommunications Telecommunications
Commands 5
Instruction 97 12
Instruction 99 12
Printer or other Instruction 96 4.1, 12
Serial device Instruction 98 12
8
4.2