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want to read from or write to via the assignable area (registers 0 to 119). 32-bit long
registers should always be aligned at even addresses. For example, if you want to read
registers 7136 (1-second V1 voltage, scaled short integer) and 14720-14721 (kWh Import,
long integer) via registers 0-2, do the following:
- write 14720 to register 120
- write 14721 to register 121
- write 7136 to register 122
Reading from registers 0-2 will return the kWh reading in registers 0 (low 16 bits) and 1
(high 16 bits), and the voltage reading in register 2.
2.9 Password Protection
The PM130 has a password protection option allowing you to protect your setups,
cumulative registers and logs from being changed or cleared through communications. You
can disable or enable password protection through communications or via the front display.
For details, refer to your instrument Installation and Operation Manual.
When password protection is enabled, the user password you set in your instrument should
be written into the device authorization register (2575) before another write request is
issued. If the correct password is not supplied while password protection is enabled, the
instrument will respond to all write requests with the exception code 01 (illegal operation).
It is recommended to clear the password register after you have completed your changes in
order to activate password protection.
2.10 Data Recording and File Transfers
2.10.1 Log File Organization
Historical files are stored to the non-volatile memory. Memory is allocated for each file
statically when you set up your files and will not change unless you re-organize the files.
The meter automatically performs de-fragmentation of the memory each time you re-
organize your files. This helps keep all free memory in one continuous chunk and thus
prevents possible leakage of memory caused by fragmentation.
Data records in a file are arranged in the order of their recording. Each record has a unique
16-bit sequence number that is incremented modulo 65536 with each new record. The
sequence number can be used to point to a particular record in the file, or to check the
sequence of records when uploading files from the device.
Each file has a write position pointer that indicates the place where the next record will be
recorded, and a read position pointer that indicates the place from where the current record
will be read. Both pointers show sequence numbers of the records they point to rather than
record offsets in the file.
After acknowledging a record you have read, the read pointer automatically advances to the
next record in the file. When the read pointer gets to the record to which the file write
pointer points, the end-of-file (EOF) flag is set. It is automatically cleared when a new
record is added to the file, or when you explicitly move the read pointer to any record
within a file.
If a file has a wrap-around attribute (circular file), the most recent records can overwrite
the oldest records. When this happens at the current read position, the read pointer
automatically advances forward in order to point to the oldest record in the file.
The meter keeps a separate read pointer for each communication port so that access to the
same file through a different port will not affect current active sessions for other ports.
Multi-section Files
Log files can have one or more (up to 8) sections for multi-channel recording. An ordinal file
consists of a single section. A daily profile log file is arranged as multi-section file.
A multi-section file is subdivided into multiple sections of the same structure, one section
per recording channel. The number of sections in each file is defined at the time you set up
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