SPEC-1587 (REV. 5)

13/18

29-09-2017

SA4106A

Motor Pulse Output (MON, MOP)

The MON and MOP pins are complimentary outputs with a

frequency

proportional

to

the

average

active

power

consumption measured. These active high outputs can be

used to either directly drive a stepper motor counter or an

electro-mechanical impulse counter. The Rated Condition

Select inputs (R0, R1, R2, R3) as well as the Fast Mode

Select input (FMS) allow the selection of different output

frequencies corresponding to different meter constants.

Figure 10 indicates the timing of these signals.

The nominal output frequency of each motor output is given

by:

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where

…(5)

STANDARD mode as per Equation 4 and

DF_MO is the motor divider selected by R0, R1, R2, R3 and

FMS according to Table 3

When connecting a stepper motor counter between MON and

MOP the output pulse rate is effectively doubled because the

pulses on both MON and MOP contribute to incrementing the

counter.

The timing values given below are based on the nominal

frequency value of the internal oscillator.

Figure 10: Motor pulse output waveform

Anti-Creep State Output (ACST)

The state of the anti-creep circuit is available on the ACST

output pin. This pin allows the state of the anti-creep circuit to

be monitored. A low level on this pin indicates that the anti-

creep circuit has detected an energy level below the

threshold set by the ACSEL pin. In this state no pulses will be

emitted on the LED and the motor pulse outputs. A high level

indicates that the detected energy is above the anti-creep

threshold and pulses will be emitted on the LED and motor

pulse outputs. The ACST pin can be used to drive an LED to

indicate when the SA4106A has detected energy below or

above the anti-creep threshold. A power-on reset will set

ACST low and the pin will go high only once energy above

the anti-creep threshold has been detected. If the anti-creep

threshold is disabled the ACST pin will go high as soon as the

logic low on ACSEL has been detected and it will remain high,

regardless what level of energy is detected.

Direction Indicator Output (DIRO)

The direction of the energy flow may be ascertained by

monitoring the DIRO pin. A low level on this pin indicates

negative energy flow. Positive energy flow is indicated by a

high level. Should the energy (either negative or positive) be

less than the anti-creep threshold then this output will retain

its previous state. This prevents a flickering output in the case

of no or very low current flow. The DIRO pin may be used to

drive an LED. The state of the DIRO pin is updated on the

internal FAST mode pulses, regardless of whether the device

is set to FAST or STANDARD mode and what state DIRI is

set to. A power-on reset will set DIRO high and it will remain

high until negative energy above the anti-creep threshold is

detected. Table 5 illustrates the operation of the DIRO output.

Table 5: Operation of the DIRO output

Energy Level

|Phase Angle|

State of DIRO

0º - 360º

Previous State

< 90º

HIGH

> 90º

LOW

t

MP

t

MS

t

M

t

MSP

MON

MOP