Campbell Scientific CR7 Measurement and Control System - Manual (Page 25)

CR7 MEASUREMENT AND CONTROL SYSTEM OVERVIEW
OV-15
OV5. 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 OV5-1
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 brought
back to the office/lab where the data is
transferred to the computer. Another
storage device is usually taken into the field
and exchanged for the one which is
retrieved so that data collection can
continue uninterrupted.
2. Bring a storage device to the datalogger
and transfer all the data that has
accumulated in Final Storage since the last
visit.
3. Retrieve the data over some form of
telecommunications link, that is, Radio
Frequency (RF), telephone, short haul
modem, multi-drop interface, or satellite.
The PC208 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 (Section 1.5)
• the power to the datalogger is turned
off.
Table OV5-1 lists the instructions used with the
various methods of data retrieval.
TABLE OV5-1. Data Retrieval Methods and Related Instructions
Storage Printer, other Telecommunications
Module Serial Device (RF, Phone, Short Haul, SC32A)
Inst. 96, Inst. 96, 98 Inst. 97
*4 *4
*9 *9 (Telecommunications Commands)
*D *D
TABLE OV5-2. Data Retrieval Sections in Manual
Topic Section in Manual
Instr. 96 4.1, 12
Instr. 97 12
*4 4.1
*8 4.2
*9 4.2
*D 1.8
Storage Module 4.3
Telecommunications 5