Energy Meter IC Family Software Instruction Manual

71M652X Software User’s Guide

Revision 1.7 TERIDIAN Proprietary 74 of 138

5.12 CE IMAGE FILES

The CE code uses pre-designed, pre-validated algorithms and calculations, which are accurate to the noise floor of the

integrated circuit, saving substantial engineering and development time.

The source code for the CE is proprietary. Only the code and data images (binary images) are available to the user.

The code image must be merged with the MPU code residing in flash memory.

Teridian provides two files for each ce code. One file is the code for the compute0engine. The other is a set of data to

copy into the CE's RAM area, to initialize the CE program variables.

Teridian has two standard CE codes for the 6521:

• For one-element two-wire single phase meters, use ce21a04_ce.c, and ce21a04_dat.c (the CE code and data

files). When the hardware field EQU is 0x00, this CE code provides two metering elements using VA and IA

and VA and IB. The equations are WhA = (VA * IA) and WhB = (VA * IB).

There are two metering elements so that the neutral current can be measured for tamper detection. The MPU

software must decide which element is more accurate at any given time. This gives a perfectly flexible

method for detecting and mitigating tampering.

For one-element three-wire split phase meters, also use ce21a04_ce.c, and ce21a04_dat.c (the CE code and

data files). When the hardware field EQU is 0x01, this ce code provides two metering elements. One has an

equation of Wh = VA (IA - IB)/2. The other has WhB = VA * IB.

There are two metering elements so that the second element can be used to reduce the calibration steps

during meter manufacturing. The second element provides the data needed to calibrate the meter with both

current sensors operating at the same time. This permits more accurate, realistic calibrations.

• For two-element three-wire delta meters, or dual non-tamper-detecting single-phase meters, use

CE21A03_CE.C and CE21A03_DAT.C. When the hardware field EQU is 02, this CE code provides two

metering elements. One has an equation of WhA = VA * IA. The other is WhB = VB * IB. This measures two

legs of a delta configuration, and therefore, by Blondel's theorem, when these are added together, the total

delivered power is metered. Since the two channels are independent, they can also be used as two single-

phase meters, even if the meters are operating on different phases.

Teridian has a number of other CE codes for other sensors and needs, including code for tamper-resistant meters.

Images of the CE data and program code are provided with the Demo Kits. They are to be linked into the object code.

CE images are provided by the following files:

1. CE21B_CE.C:

This file provides the image of the 6521 CE program in C notation.

2. CE21C_DAT.C:

This file provides the image of the 6521 CE default data in C notation.

5.13 COMMON MPU ADDRESSES

In the Demo Code, certain MPU XRAM parameters have been given fixed addresses in order to permit easy external

access. These variables can be read via the command line interface (if available), with the )n$ command and written

with the )n=xx command where n is the word address. Note that accumulation variables are 64 bits long and are

accessed with )n$$ (read) and )n=hh=ll (write) in the case of accumulation variables.