EVAL-ADE7756EB

–6–

REV. PrB 01/01

PRELIMINARYTECHNICALDATA

ADE7756 EVALUATION SOFTWARE

ADE7756 EVALUATION SOFTWARE

ADE7756 EVALUATION SOFTWARE

ADE7756 EVALUATION SOFTWARE

ADE7756 EVALUATION SOFTWARE

The AD7756 evaluation board is supported by Windows

based software which will allow the user to access all the

functionality of the ADE7756. The software is designed to

communicate with the ADE7756 evaluation board via the

parallel port of the PC.

Installing the AD7756 Software

The ADE7756 Software is supplied on three 3.5'' 1.44MB

floppy disks. The minimum requirements for the PC are

Pentium II 233MHz, 32 MB RAM, 10MB free HD space

and at least one PS/2 or ECP parallel port . To install the

software place disk #1 in the floppy drive and double click

"setup.exe". This will launch the set up program which

will automatically install all the software components

including the uninstall program and create the required

directories. When the set up program has finished install-

ing the "ADE7756Eval" program the user will be

prompted to install the National Instruments

run-time

engine. This software was developed using National

Instruments LabView software and the run-time engine is

required in order to run the "ADE7756Eval" program.

When prompted simply place disk #2 in the floppy drive

and hit return. Follow the on-screen instructions to

complete the installation. You will need to reboot your

computer to complete the installation.

To launch the software simply go to the

Start—>Programs—>ADE7756 menu and click on

"ADE7756Eval".

Uninstalling the ADE7756 Evaluation Software

Both the "ADE7756Eval" program and the NI run-time

engine are easily uninstalled by using the Add/Remove

Programs facility in the control panel. Simply select the

program to uninstall and click the Add/Remove button.

Figure 7 — Uninstalling the ADE7756 Eval Software

Metering Mode

When the software is launched, the program automatically

starts in Meter Mode. In this mode the evaluation board

can be used as a fully functional energy meter. When the

appropriate line voltage, test current, frequency, and meter

constant have been set up, the user can use the calibration

routine to remove any error associated with the transduc-

ers. The CF output can be used with a standard frequency

counter to check the accuracy. The measured CF output

frequency should be adjusted to match the theoretical CF

freq. of the Eval software.

Note that the calibration routine does not automatically

remove phase errors associated with a CT or other

transducer. These must be removed first by using the

ADE7756 PHCAL Register. This is explained later.

Instantaneous Power, Voltage, and Current RMS calcula-

tions are also available in this window. They are processed

using the Waveform Sampling routine with the number of

samples defined in this mode.

Figure 8 - Meter Mode

Note also that the input signal range and gain must be set

for the PGAs on the Channel 1 and Channel 2. This will

ensure that the output signal range from the transducers is

matched to the analog inputs. For example, in the meter

example shown in Figure 6 the line voltage is attenuated

to approximately 215mV rms or 300mV peak. By select-

ing a gain of 2 for the PGA in Channel 2, the peak

differential input signal is set to 500mV. Similarly for

Channel 1, assuming a maximum current of 120A the

maximum differential output signal from the CT is

300mV. Therefore the full-scale differential input signal

level is set to 500mV by setting the gain to 2—see Table I

in the ADE7756 data sheet.

The PGA settings are made

through the main selection menu. To get to the main

selection menu click the "Quit to Menu" button at any

time.