3.1.10 Pulse Meter Constant Register x (x = 0, 1, 2)

The PULSE0_K_t, PULSE1_K_t, and PULSE2_K_t registers define the meter test constants for pulses: 0, 1, and 2. The meter constant represents the amount of energy signified by a single output pulse. The type of energy is specified in the PCx_TYPE field of the corresponding PULSEx_CTRL register.

The PULSEx_K_t register is expressed in the following units, depending on the energy type:

[Wh/pulse] for active energy
[VARh/pulse] for reactive energy
[VAh/pulse] for apparent energy
[Amp²-h/pulse] for Amp²

All values are represented in uQ8.24 format.

In Europe and Asia, the pulse constant (MC) is commonly used with units, such as [pulses/kWh], [pulses/kVARh], [pulses/kVAh], or [pulses/kAmp²-h]. To compute the value to be written in the pulse meter constant register for an specific MC, divide 1000 by the MC and then convert the result into uQ8.24 format by multiplying by 2²⁴. For example:

Active power: MC = 800 pulses/kWh

1000/800 = 1.25 Wh/pulse

Value to program in PULSEx_K_t: round (1.25 * 2²⁴) = 20,971,520 (0x01400000)
Reactive power: MC = 1000 pulses/kVARh

1000/1000 = 1 VARh/pulse

Value to program in PULSEx_K_t: round (1 * 2²⁴) = 16,777,216 (0x01000000)
Amp squared: MC = 3200 pulses/kAmp²-h

1000 / 3200 = 0.3125 Amp²-h/pulse

Value to program in PULSEx_K_t: round (0.3125 * 2²⁴) = 5,242,880 (0x00500000)
Apparent power: MC = 800 pulses/kVAh

1000 / 800 = 1.25 VAh/pulse

Value to program in PULSEx_K_t: round (1.25 * 2²⁴) = 20,971,520 (0x01400000)

The frequency of pulse output generated depends on the quantity of energy measured and the defined pulse constants.

Important: There is a limitation on the maximum frequency of pulse occurrence. The pulse width plus 500 microseconds cannot exceed the pulse period duration.

For example, if the pulse width is set at 500 microseconds, the maximum pulse frequency that can be attained is 1 kHz. On the other hand, if the pulse width is reduced to 50 microseconds, the pulse frequency can increase to a maximum of 1.818 kHz.

Updates to PULSEx_K_t take effect at the next negative zero-crossing (narrow-band filtered version) of the present control phase voltage channel.

Name:	PULSEx_K_t
Property:	Read-Write


Bit	31	30	29	28	27	26	25	24
	Pulsex_K_t[31:24]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0


Bit	23	22	21	20	19	18	17	16
	Pulsex_K_t[23:16]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0


Bit	15	14	13	12	11	10	9	8
	Pulsex_K_t[15:8]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0


Bit	7	6	5	4	3	2	1	0
	Pulsex_K_t[7:0]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0

3.1.10 Pulse Meter Constant Register x (x = 0, 1, 2)

Bits 31:0 – Pulsex_K_t[31:0] (uQ8.24)