GE EPM 9650/9800 manual Direct Adjustment Interface, As Stored LSB

Direct Adjustment Interface

Block Timestamp

Calibration Modification Selection Calibration Timestamp

Gain Factors VAN, VBN, VCN, VXN

Gain Factor IA, 150mA, 250mA, 500mA, 1A, 2.5A, 5A

Gain Factors IB, IC, INM Unused

Phase Comp IA, 500mA, 1A, 2.5A, 5A, 10A Phase Comp IB, IC

Unused

Calibration Checksum Block Checksum

Factory Read	CTPT Read	Modification
60929-60932	61027-61030
		61185
60933-60936	61030-61034	61186-61189
60937-60944	61035-61042	61190-61197
60945-60956	61043-61054	61198-61209
60957-60992	61055-61090	61210-61245
60993	61091	61246
60994-60998	61092-61096	61247-61251
60999-61025	61097-61106	61252-61278
61009-61025	61107-61123	61262-61278
61026	61124	61279
		61280

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.

Voltage Gain Factor: 4 byte signed LSB values with 15 bits of fraction that are used as a multiplicative factor.

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%)

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