GE Power Quality Meter Series, Инструкция по эксплуатации

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A-12 PQM Power Quality Meter GE Power Management
A.1 PQM APPLICATION NOTES APPENDIX A
A
A.1.6 DATA LOGGER IMPLEMENTATION
APPLICATION NOTE PQMAN06: DATA LOGGER IMPLEMENTATION
The Data Logger allows various user defined parameters to be continually recorded at a user defined rate. The
Data Logger uses 64 samples/cycle data. The PQM has allocated 65536 bytes of memory for Data Log stor-
age. The memory structure is partitioned into 512 blocks containing 64
×
2 byte registers as shown below:
Figure A–1: DATA LOGGER MEMORY STRUCTURE
Each entry into the Data Log is called a Record. The Record can vary in size depending upon the parameters
the user wishes to log. The memory structure can also be partitioned into 2 separate Data Logs. The 2 logs
can be user defined in size, or can be optimized by PQMPC. The top of each Data Log contains what is called
the Header. Each Data Log Header contains the following information…
• Log Time Interval: This is the user defined interval at which the data log will store entries
• Present Log Time and Date: This is the time and date of the most recent Record
• Log Start Address: This is the start address for the beginning of the logged data
• Log Record Size: This is the size of each Record entry into the Data Log based upon the user defined
Data Log structure
• Log Total Records: This is the total number of records available based upon the user defined Data Log
parameter structure
• Log Pointer to First Item of First Record: This is a pointer to the first record in the Data Log
• Log Pointer to First Item of Record After Last: This is a pointer to the next record to be written into the
Data Log
• Log Status: This reports the current status of the Data Log; i.e.: Running or Stopped
• Log Records Used: This is the number of records that have been written into the Data Log
• Log Time Remaining Until Next Reading: This is a counter showing how much time remains until the
next record is to be written into the Data Log
The Data Logger has 2 modes of operation, Run to Fill and Circulate. In the Run to Fill mode, the Data Log
will stop writing records into the memory structure when there is not enough memory to add another record.
Depending on the size of each record, the Data Log may not necessarily use the entire 65536 bytes of storage
available. In the Circulate mode, the Data Log will continue to write new Records into the Log beyond the last
REGISTER 1 BLOCK 0
BLOCK 1
BLOCK 510
BLOCK 2
BLOCK 511
REGISTER 1
REGISTER 1
REGISTER 1
REGISTER 1
REGISTER 2
REGISTER 2
REGISTER 2
REGISTER 2
REGISTER 2
REGISTER 64
REGISTER 64
REGISTER 64
REGISTER 64
REGISTER 64