sames

SA2102D

9/16

http://www.sames.co.za

Motor pulses / kWh =

......... 2

LED pulses/kWh / DF_MO

Where:

LED pulses / kWh as calculated in formula 1

DF_MO is the dividing factor and depends on R1 and R0:

R1

0

0

1

1

R0

0

1

0

1

DF_MO

64

32

16

8

Select Output (SO)

Rated Condition Select (R0, R1, R2)

LED pulses / kWh =

......... 1

The SA2102D has unique internal circuitry that can be user

enabled to stabilize the LED output. When in FAST mode,

connecting the SO input pin to Vdd will enable the LED pulse

stability feature. Stabilizing the LED pulse output allows for

shorter meter calibration times. Leaving the SO pin open or

connecting to Vss will disable the LED pulse stability circuitry.

Figure 9 indicates the operation of pulse stability.

To calculate the LED output pulse rate (in STANDARD mode)

and motor drive pulse rate for any meter ratings (I

and V

)

the following formulae can be used:

1160 x (1/DF_LED) x

Where:

I

= Maximum Rated Mains current

V

= Nominal Mains Voltage

DF_LED is the dividing factor and depends on R2, R1 and R0:

The Rated Condition Select pins R0, R1 and R2 are inputs pins

used to configure the SA2102D for different Maximum Rated

Mains Currents and Nominal Mains Voltages. This feature

allows for the use of different stepper motor gear ratios.

MAX

NOM

NOM

MA

X

100

100

100

100

100

100

100

6400

3200

1600

800

6400

3200

1600

220V/10A

220V/20A

220V/40A

220V/80A

220V/6A

220V/30A

220V/60A

0

1

0

1

0

1

0

0

0

1

1

0

0

1

0

0

0

0

1

1

1

MOP and MON

Outputs

(Pulses/kWh)

LED Output

(Pulses/

kWh)

Vnom / Imax

R0

R1

R2

Table 3: Some meter constants available for several maximum

currents (I

) and with a line voltage of 220V, while in

STANDARD mode.

MAX

3600

(V

x I

) / 1000

NOM

MAX

R2

0

0

0

0

1

1

1

R1

0

0

1

1

0

0

1

R0

0

1

0

1

0

1

0

DF_LED

322

322

322

322

536

214

214

Table 3 shows some of the meter constants available for

several maximum currents (I

) and with a line voltage of

220V while in STANDARD mode.

Note that the values calculated using formulae 1 and 2 are

close approximations to the values listed in table 3. The

SA2102D has to be calibrated (using the voltage input) to give

the exact value listed.

MAX

Table 1: LED Output Constants

Table 2: MOTOR Output Constants

Direction Select Input (DIRI)

Depending on the state of the DIRI pin the energy to be

measured can be in the positive direction only, or in the

negative direction only, or in both directions.

Connecting DIRI to VDD will result in energy only being

measured in the positive direction. Energy flowing in the

negative direction will not be measured. Connecting DIRI to

VSS will result in energy only being measured in the negative

direction. Energy flowing in the positive direction will not be

measured. Connecting the DIRI pin to the DIRO output pin

enables the bi-direction mode where energy is measured

regardless of direction.