SA2102D
sames
Select Output (SO)
Table 3 shows some of the meter constants available for
several maximum currents (IMAX) and with a line voltage of
220V while in STANDARD mode.
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.
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.
Rated Condition Select (R0, R1, R2)
R2 R1 R0 Vnom / Imax LED Output MOP and MON
Outputs
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.
(Pulses/
kWh)
(Pulses/kWh)
0
0
0
0
1
1
1
0
0
1
1
0
0
1
0
1
0
1
0
1
0
220V/10A
220V/20A
220V/40A
220V/80A
220V/6A
6400
3200
1600
800
100
100
100
100
100
100
100
To calculate the LED output pulse rate (in STANDARD mode)
and motor drive pulse rate for any meter ratings (IMAX and VNOM
)
the following formulae can be used:
6400
3200
1600
220V/30A
220V/60A
LED pulses / kWh =
3600
1160 x (1/DF_LED) x
(VNOM x IMAX) / 1000
Table 3: Some meter constants available for several maximum
currents (IMAX) and with a line voltage of 220V, while in
Where:
......... 1
IM XA= Maximum Rated Mains current
VNOM = Nominal Mains Voltage
STANDARD mode.
DF_LED is the dividing factor and depends on R2, R1 and R0:
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.
R2
0
R1
0
R0
0
DF_LED
322
0
0
1
322
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.
0
1
0
322
0
1
1
322
1
0
0
536
1
0
1
214
1
1
0
214
Table 1: LED Output Constants
Motor pulses / kWh = LED pulses/kWh / DF_MO
Where:
......... 2
LED pulses / kWh as calculated in formula 1
DF_MO is the dividing factor and depends on R1 and R0:
R1
0
R0
0
DF_MO
64
32
16
8
0
1
1
0
1
1
Table 2: MOTOR Output Constants
9/16
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