71M6542F MAXIM [Maxim Integrated Products], 71M6542F Datasheet - Page 129

• Manufacturer Part Number: 71M6542F
• Description: 0.1% Accuracy Over 2000:1 Current Range Energy Meter ICs
• Manufacturer: MAXIM [Maxim Integrated Products]

The FREQSEL[1:0] field in CECONFIG (CE RAM 0x20[7:6]) selects the phase that is utilized to generate a sag
interrupt. Thus, a SAG_INT event occurs when the selected phase has satisfied the sag event criteria as
set by the SAG_THR (CE RAM 0x24) register and the SAG_CNT field in CECONFIG (CE RAM 0x20[19:8]).
When the SAG_INT bit (CE RAM 0x20[20]) is set to 1, a sag event generates a transition on the YPULSE
output. In a two-phase system (71M6542F/G), and after a sag interrupt, the MPU should change the
FREQSEL[1:0] setting to select the other phase, if it is powered. Even though a sag interrupt is only
generated on the selected phase, both phases are simultaneously checked for sag. The presence of
power on a given phase can be sensed by directly checking the SAG_A and SAG_B bits in CESTATUS (CE
RAM 0x80[0:1]).
The EXT_TEMP bit enables temperature compensation by the MPU, when set to 1. When 0, internal (CE)
temperature compensation is enabled.
The CE pulse generator can be controlled by either the MPU (external) or CE (internal) variables. Control is by
the MPU if the EXT_PULSE bit = 1 (CE RAM 0x20[5]). In this case, the MPU controls the pulse rate (external
pulse generation) by placing values into APULSEW and APULSER (CE RAM 0x45 and 0x49). By setting
EXT_PULSE = 0, the CE controls the pulse rate based on WSUM_X (CE RAM 0x84) and VARSUM_X (CE
RAM 0x88).
5.3.8 CE Transfer Variables
Address
0x24
0x40
0x41
0x42
4:2
CE
5
1
0
The 71M6541D/F/G and 71M6542F/G Demo Code creep function halts both internal and external
pulse generation.
GAIN_ADJ0
GAIN_ADJ1
GAIN_ADJ2
PULSE_SLOW
PULSE_FAST
SAG_THR
EXT_PULSE
Name
Reserved
Table 84: Sag Threshold and Gain Adjust Control
2.39*10
Default
16384
16384
16384
1
0
0
0
7
Description
The voltage threshold for sag warnings. The default value is
equivalent to 113Vpk or 80 Vrms if VMAX = 600 Vrms.
This register scales the voltage measurement channels VA and
VB*. The default value of 16384 is equivalent to unity gain (1.000).
*71M6542F/G only
This register scales the IA current channel for Phase A. The
default value of 16384 is equivalent to unity gain (1.000).
This register scales the IB current channel for Phase B. The
default value of 16384 is equivalent to unity gain (1.000).
When zero, causes the pulse generators to respond to internal
data (WPULSE = WSUM_X (CE RAM 0x84), VPULSE = VARSUM_X
(CE RAM 0x88)). Otherwise, the generators respond to values the
MPU places in APULSEW and APULSER (CE RAM 0x45 and 0x49).
Reserved.
When PULSE_FAST = 1, the pulse generator input is increased
16x. When PULSE_SLOW = 1, the pulse generator input is
reduced by a factor of 64. These two parameters control the
pulse gain factor X (see table below). Allowed values are either
1 or 0. Default is 0 for both (X = 6).
PULSE_FAST PULSE_SLOW
0
1
0
1
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71M6541D/F/G and 71M6542F/G Data Sheet
0
0
1
1
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1.5 * 2
1.5 * 2
1.5 * 2
Do not use
-4
= 0.09375
X
6
2
−9
= 96
= 6