5-17
QDirect Adjustment Interface
Calibration data can be read and modified using the above registers.
Factory Calibration and CT/PT Compensation Calibration are available in the above blocks.
The Block Timestamp indicates when the data you are reading was last refreshed for viewing.
The Calibration Timestamp indicates when calibration information was last modified. This is either
updated automatically when manual adjustments are performed, or is provided as part of the block
when direct adjustments are performed.
The Calibration Checksum is a CRC16 checksum computed over all calibration information from
the Calibration Timestamp through to the last unused byte before the Calibration Checksum. It is
either automatically computed when manual adjustments are performed, or is provided as part of the
block when direct adjustments are performed.
When performing a direct adjustment, in addition to providing a properly checksummed table of
calibration data, a selection indicating whether the table should update the Factory calibration or the
CT/PT calibration needs to be provided. This selection should be 0x00000 for Factory Calibration
and 0x00100 for CT/PT Compensation. To verify the selection, a Block Checksum must be
computed from the Calibration Modification Selection through to the Calibration Checksum.
QVoltage Gain Factor: 4 byte signed LSB values with 15 bits of fraction that are used as a
multiplicative factor.
CTPT Read Modification
Block Timestamp
Factory Read
60929-60932 61027-61030
Calibration Modification Selection 61185
Calibration Timestamp 60933-60936 61030-61034 61186-61189
Gain Factors VAN, VBN, VCN, VXN 60937-60944 61035-61042 61190-61197
Gain Factor IA, 150mA, 250mA, 500mA, 1A,
2.5A, 5A 60945-60956 61043-61054 61198-61209
Gain Factors IB, IC, INM 60957-60992 61055-61090 61210-61245
Unused 60993 61091 61246
Phase Comp IA, 500mA, 1A, 2.5A, 5A, 10A 60994-60998 61092-61096 61247-61251
Phase Comp IB, IC60999-61025 61097-61106 61252-61278
Unused 61009-61025 61107-61123 61262-61278
Calibration Checksum 61026 61124 61279
Block Checksum 61280
As Stored (LSB) MSB Decimal Scaled Meaning
0x000800000 0x000008000 32768 1.00000 x*1.00 (unity)
0x0CC8C0000 0x000008CCC 36044 1.09998 x*1.10 (magnification 10%)
0x033730000 0x000007333 29491 0.89999 x*0.90 (diminution 10%)