I could not calibrate the MSP430FE427.
As I'm reading the datasheet, I noticed that at the calibration section there was nothing about the PHASE correction; only it adjust the GAIN correction and the OFFSET.

and overall the datasheet and the application note are note clear to me.

did anyone succeed in calibrating or using the MSP430FE427 chip in designing a single phase meter?

------------------------------------

______________________________
Stellaris® MCU Family: New Parts, New Package, New Price.


(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )

The MSP430FE427 data-sheet says very little about calibration.
Which Application Note did you read?
Did you read the ESP430 Peripheral Modules User's Manual?

--- In m...@yahoogroups.com, "smhhadima" wrote:
>
> I could not calibrate the MSP430FE427.
> As I'm reading the datasheet, I noticed that at the calibration section there was nothing about the PHASE correction; only it adjust the GAIN correction and the OFFSET.
>
> and overall the datasheet and the application note are note clear to me.
>
> did anyone succeed in calibrating or using the MSP430FE427 chip in designing a single phase meter?
>
------------------------------------



(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )

OCY, he seems to want to calibrate his application (he wants PHASE
calibration).
So, it also means he doesn't know what he is doing and how the
application works.
Therefore, he must study the application and the mathematics
necessary for a power rail single phase meter... before asking this
kind of question...
-Augusto
On Qua 09/09/09 18:46 , "old_cow_yellow" o...@yahoo.com
sent:
The MSP430FE427 data-sheet says very little about calibration.
Which Application Note did you read?
Did you read the ESP430 Peripheral Modules User's Manual?
--- In m...@yahoogroups.com, "smhhadima" ..> wrote:
>
> I could not calibrate the MSP430FE427.
> As I'm reading the datasheet, I noticed that at the calibration
section there was nothing about the PHASE correction; only it adjust
the GAIN correction and the OFFSET.
>
> and overall the datasheet and the application note are note clear
to me.
>
> did anyone succeed in calibrating or using the MSP430FE427 chip in
designing a single phase meter?
>

[Non-text portions of this message have been removed]

------------------------------------



(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )

I agree with you.

The ESP430 module does have some hardware features to facilitate calibration. The firmware should utilize these features to calibrate the sensors.

--- In m...@yahoogroups.com, Augusto Einsfeldt wrote:
>
>
> OCY, he seems to want to calibrate his application (he wants PHASE
> calibration).
> So, it also means he doesn't know what he is doing and how the
> application works.
> Therefore, he must study the application and the mathematics
> necessary for a power rail single phase meter... before asking this
> kind of question...
> -Augusto
> On Qua 09/09/09 18:46 , "old_cow_yellow" old_cow_yellow@...
> sent:
> The MSP430FE427 data-sheet says very little about calibration.
> Which Application Note did you read?
> Did you read the ESP430 Peripheral Modules User's Manual?
> --- In m...@yahoogroups.com, "smhhadima" ..> wrote:
> >
> > I could not calibrate the MSP430FE427.
> > As I'm reading the datasheet, I noticed that at the calibration
> section there was nothing about the PHASE correction; only it adjust
> the GAIN correction and the OFFSET.
> >
> > and overall the datasheet and the application note are note clear
> to me.
> >
> > did anyone succeed in calibrating or using the MSP430FE427 chip in
> designing a single phase meter?
> >
>
> [Non-text portions of this message have been removed]
>
------------------------------------



(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )

Perhaps the OP, original poster, meant the following by phase
calibration. "Current-Transformer Phase-Shift Compensation and
Calibration" If so the OP should take a look at SLAA122 - February 2001.
The OP may also be interested in SLAA203C–June 2004–Revised April 2009,
Implementing An Electronic Watt-Hour Meter With MSP430FE42x(A)/FE42x2.

Howard
old_cow_yellow wrote:
>
> The MSP430FE427 data-sheet says very little about calibration.
> Which Application Note did you read?
> Did you read the ESP430 Peripheral Modules User's Manual?
>
> --- In m...@yahoogroups.com ,
> "smhhadima" wrote:
> >
> > I could not calibrate the MSP430FE427.
> > As I'm reading the datasheet, I noticed that at the calibration
> section there was nothing about the PHASE correction; only it adjust
> the GAIN correction and the OFFSET.
> >
> > and overall the datasheet and the application note are note clear to me.
> >
> > did anyone succeed in calibrating or using the MSP430FE427 chip in
> designing a single phase meter?
> >

------------------------------------



(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )

Hi,

the problem is: when I do the clibration at the clibration point which is 230V/ 10A/ 60 the meter displays the readings correct. when I adjusted the source to supply 230V/10A/0 phase shift, if found the displayed current change to 8.7A (although the clamp still reading 10A)

Moreover, when I turn the current source off 0A (while leaving the 230V), the chip sees current of 2.2A. So I tried to use the I1OFFSET to ajust the current but it did not work. So I activated the DC-REMove for the current but also it did not work.

Finally, I removed the jumber which connects the current input and voltage input to the VSS. I clibrated again then I changed the source phase shift to 0 and this time the results was correct and the current stayed at 10A

But when I sourced 0A the meter displayed 407mA and I could not remove it with IOFFSET and when I disconnect the AC the meter displayed 42mA while it is running on battery)

my questions are:
1-how can I offset this readings to 0A or is this a problem with the FE427 crosstalk?

2- when should I connect the Voltage and current input to the GND and when I should leave them floating?

Sam Hadima

--- In m...@yahoogroups.com, "old_cow_yellow" wrote:
>
> I agree with you.
>
> The ESP430 module does have some hardware features to facilitate calibration. The firmware should utilize these features to calibrate the sensors.
>
> --- In m...@yahoogroups.com, Augusto Einsfeldt wrote:
> >
> >
> > OCY, he seems to want to calibrate his application (he wants PHASE
> > calibration).
> > So, it also means he doesn't know what he is doing and how the
> > application works.
> > Therefore, he must study the application and the mathematics
> > necessary for a power rail single phase meter... before asking this
> > kind of question...
> > -Augusto
> > On Qua 09/09/09 18:46 , "old_cow_yellow" old_cow_yellow@
> > sent:
> > The MSP430FE427 data-sheet says very little about calibration.
> > Which Application Note did you read?
> > Did you read the ESP430 Peripheral Modules User's Manual?
> > --- In m...@yahoogroups.com, "smhhadima" ..> wrote:
> > >
> > > I could not calibrate the MSP430FE427.
> > > As I'm reading the datasheet, I noticed that at the calibration
> > section there was nothing about the PHASE correction; only it adjust
> > the GAIN correction and the OFFSET.
> > >
> > > and overall the datasheet and the application note are note clear
> > to me.
> > >
> > > did anyone succeed in calibrating or using the MSP430FE427 chip in
> > designing a single phase meter?
> > >
> >
> >
> >
> > [Non-text portions of this message have been removed]
>

------------------------------------



(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )

HINT - What trigonometric value of a reading that changed between your
examples, rounded to 2 figures, is 0.87.

Al

smhhadima wrote:
> Hi,
>
> the problem is: when I do the clibration at the clibration point which is 230V/ 10A/ 60 the meter displays the readings correct. when I adjusted the source to supply 230V/10A/0 phase shift, if found the displayed current change to 8.7A (although the clamp still reading 10A)
>
> Moreover, when I turn the current source off 0A (while leaving the 230V), the chip sees current of 2.2A. So I tried to use the I1OFFSET to ajust the current but it did not work. So I activated the DC-REMove for the current but also it did not work.
>
> Finally, I removed the jumber which connects the current input and voltage input to the VSS. I clibrated again then I changed the source phase shift to 0 and this time the results was correct and the current stayed at 10A
>
> But when I sourced 0A the meter displayed 407mA and I could not remove it with IOFFSET and when I disconnect the AC the meter displayed 42mA while it is running on battery)
>
> my questions are:
> 1-how can I offset this readings to 0A or is this a problem with the FE427 crosstalk?
>
> 2- when should I connect the Voltage and current input to the GND and when I should leave them floating?
>
> Sam Hadima
>
> --- In m...@yahoogroups.com, "old_cow_yellow" wrote:
>> I agree with you.
>>
>> The ESP430 module does have some hardware features to facilitate calibration. The firmware should utilize these features to calibrate the sensors.
>>
>> --- In m...@yahoogroups.com, Augusto Einsfeldt wrote:
>>>
>>> OCY, he seems to want to calibrate his application (he wants PHASE
>>> calibration).
>>> So, it also means he doesn't know what he is doing and how the
>>> application works.
>>> Therefore, he must study the application and the mathematics
>>> necessary for a power rail single phase meter... before asking this
>>> kind of question...
>>> -Augusto
>>> On Qua 09/09/09 18:46 , "old_cow_yellow" old_cow_yellow@
>>> sent:
>>> The MSP430FE427 data-sheet says very little about calibration.
>>> Which Application Note did you read?
>>> Did you read the ESP430 Peripheral Modules User's Manual?
>>> --- In m...@yahoogroups.com, "smhhadima" ..> wrote:
>>> >
>>> > I could not calibrate the MSP430FE427.
>>> > As I'm reading the datasheet, I noticed that at the calibration
>>> section there was nothing about the PHASE correction; only it adjust
>>> the GAIN correction and the OFFSET.
>>> >
>>> > and overall the datasheet and the application note are note clear
>>> to me.
>>> >
>>> > did anyone succeed in calibrating or using the MSP430FE427 chip in
>>> designing a single phase meter?
>>> >
>>>
>>>
>>>
>>> [Non-text portions of this message have been removed]
>>>
> ------------------------------------



(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )

Some thing is suspicious. Changing the phase relationship between
current and voltage shouldn't affect the value of a current reading when
the amplitude of the current is held constant. Yes changing the phase
relationship will change the power relationship.

What does 60 in "230V/10A/60" stand for? Does 60 here mean 60 cycles or
does it mean 60 degrees?

Howard
OneStone wrote:
>
>
> HINT - What trigonometric value of a reading that changed between your
> examples, rounded to 2 figures, is 0.87.
>
> Al
>
> smhhadima wrote:
> > Hi,
> >
> > the problem is: when I do the clibration at the clibration point
> which is 230V/ 10A/ 60 the meter displays the readings correct. when I
> adjusted the source to supply 230V/10A/0 phase shift, if found the
> displayed current change to 8.7A (although the clamp still reading 10A)
> >
> > Moreover, when I turn the current source off 0A (while leaving the
> 230V), the chip sees current of 2.2A. So I tried to use the I1OFFSET
> to ajust the current but it did not work. So I activated the DC-REMove
> for the current but also it did not work.
> >
> > Finally, I removed the jumber which connects the current input and
> voltage input to the VSS. I clibrated again then I changed the source
> phase shift to 0 and this time the results was correct and the current
> stayed at 10A
> >
> > But when I sourced 0A the meter displayed 407mA and I could not
> remove it with IOFFSET and when I disconnect the AC the meter
> displayed 42mA while it is running on battery)
> >
> > my questions are:
> > 1-how can I offset this readings to 0A or is this a problem with the
> FE427 crosstalk?
> >
> > 2- when should I connect the Voltage and current input to the GND
> and when I should leave them floating?
> >
> > Sam Hadima
> >
> > --- In m...@yahoogroups.com ,
> "old_cow_yellow" wrote:
> >> I agree with you.
> >>
> >> The ESP430 module does have some hardware features to facilitate
> calibration. The firmware should utilize these features to calibrate
> the sensors.
> >>
> >> --- In m...@yahoogroups.com ,
> Augusto Einsfeldt wrote:
> >>>
> >>> OCY, he seems to want to calibrate his application (he wants PHASE
> >>> calibration).
> >>> So, it also means he doesn't know what he is doing and how the
> >>> application works.
> >>> Therefore, he must study the application and the mathematics
> >>> necessary for a power rail single phase meter... before asking this
> >>> kind of question...
> >>> -Augusto
> >>> On Qua 09/09/09 18:46 , "old_cow_yellow" old_cow_yellow@
> >>> sent:
> >>> The MSP430FE427 data-sheet says very little about calibration.
> >>> Which Application Note did you read?
> >>> Did you read the ESP430 Peripheral Modules User's Manual?
> >>> --- In m...@yahoogroups.com ,
> "smhhadima" ..> wrote:
> >>> >
> >>> > I could not calibrate the MSP430FE427.
> >>> > As I'm reading the datasheet, I noticed that at the calibration
> >>> section there was nothing about the PHASE correction; only it adjust
> >>> the GAIN correction and the OFFSET.
> >>> >
> >>> > and overall the datasheet and the application note are note clear
> >>> to me.
> >>> >
> >>> > did anyone succeed in calibrating or using the MSP430FE427 chip in
> >>> designing a single phase meter?
> >>> >
> >>>
> >>>
> >>>
> >>> [Non-text portions of this message have been removed]
> >>>
> >
> >
> >
> >
> > ------------------------------------
> >
> >
> >
> >

______________________________
Stellaris® MCU Family: New Parts, New Package, New Price.


(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )

240V/ 10A/ 60Phase shift (PF=.5)
Sorry for not beenig clear
--- In m...@yahoogroups.com, Howard Hansen wrote:
>
> Some thing is suspicious. Changing the phase relationship between
> current and voltage shouldn't affect the value of a current reading when
> the amplitude of the current is held constant. Yes changing the phase
> relationship will change the power relationship.
>
> What does 60 in "230V/10A/60" stand for? Does 60 here mean 60 cycles or
> does it mean 60 degrees?
>
> Howard
> OneStone wrote:
> >
> >
> > HINT - What trigonometric value of a reading that changed between your
> > examples, rounded to 2 figures, is 0.87.
> >
> > Al
> >
> > smhhadima wrote:
> > > Hi,
> > >
> > > the problem is: when I do the clibration at the clibration point
> > which is 230V/ 10A/ 60 the meter displays the readings correct. when I
> > adjusted the source to supply 230V/10A/0 phase shift, if found the
> > displayed current change to 8.7A (although the clamp still reading 10A)
> > >
> > > Moreover, when I turn the current source off 0A (while leaving the
> > 230V), the chip sees current of 2.2A. So I tried to use the I1OFFSET
> > to ajust the current but it did not work. So I activated the DC-REMove
> > for the current but also it did not work.
> > >
> > > Finally, I removed the jumber which connects the current input and
> > voltage input to the VSS. I clibrated again then I changed the source
> > phase shift to 0 and this time the results was correct and the current
> > stayed at 10A
> > >
> > > But when I sourced 0A the meter displayed 407mA and I could not
> > remove it with IOFFSET and when I disconnect the AC the meter
> > displayed 42mA while it is running on battery)
> > >
> > > my questions are:
> > > 1-how can I offset this readings to 0A or is this a problem with the
> > FE427 crosstalk?
> > >
> > > 2- when should I connect the Voltage and current input to the GND
> > and when I should leave them floating?
> > >
> > > Sam Hadima
> > >
> > > --- In m...@yahoogroups.com ,
> > "old_cow_yellow" wrote:
> > >> I agree with you.
> > >>
> > >> The ESP430 module does have some hardware features to facilitate
> > calibration. The firmware should utilize these features to calibrate
> > the sensors.
> > >>
> > >> --- In m...@yahoogroups.com ,
> > Augusto Einsfeldt wrote:
> > >>>
> > >>> OCY, he seems to want to calibrate his application (he wants PHASE
> > >>> calibration).
> > >>> So, it also means he doesn't know what he is doing and how the
> > >>> application works.
> > >>> Therefore, he must study the application and the mathematics
> > >>> necessary for a power rail single phase meter... before asking this
> > >>> kind of question...
> > >>> -Augusto
> > >>> On Qua 09/09/09 18:46 , "old_cow_yellow" old_cow_yellow@
> > >>> sent:
> > >>> The MSP430FE427 data-sheet says very little about calibration.
> > >>> Which Application Note did you read?
> > >>> Did you read the ESP430 Peripheral Modules User's Manual?
> > >>> --- In m...@yahoogroups.com ,
> > "smhhadima" ..> wrote:
> > >>> >
> > >>> > I could not calibrate the MSP430FE427.
> > >>> > As I'm reading the datasheet, I noticed that at the calibration
> > >>> section there was nothing about the PHASE correction; only it adjust
> > >>> the GAIN correction and the OFFSET.
> > >>> >
> > >>> > and overall the datasheet and the application note are note clear
> > >>> to me.
> > >>> >
> > >>> > did anyone succeed in calibrating or using the MSP430FE427 chip in
> > >>> designing a single phase meter?
> > >>> >
> > >>>
> > >>>
> > >>>
> > >>> [Non-text portions of this message have been removed]
> > >>>
> > >
> > >
> > >
> > >
> > > ------------------------------------
> > >
> > >
> > >
> > >



(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )

Sin(60)=0.8660 * 10 = 8.66 ~ 8.7. You've calibrated with a 60 degree
phase shift, depending on how you are processing the data later you
cannot simply ignore this. To me this number jumps out from the page. It
may turn out to be irrelevant, but when all else sems to fail look for
the obvious

Al

smhhadima wrote:
> 240V/ 10A/ 60Phase shift (PF=.5)
> Sorry for not beenig clear
> --- In m...@yahoogroups.com, Howard Hansen wrote:
>> Some thing is suspicious. Changing the phase relationship between
>> current and voltage shouldn't affect the value of a current reading when
>> the amplitude of the current is held constant. Yes changing the phase
>> relationship will change the power relationship.
>>
>> What does 60 in "230V/10A/60" stand for? Does 60 here mean 60 cycles or
>> does it mean 60 degrees?
>>
>> Howard
>> OneStone wrote:
>>>
>>>
>>> HINT - What trigonometric value of a reading that changed between your
>>> examples, rounded to 2 figures, is 0.87.
>>>
>>> Al
>>>
>>> smhhadima wrote:
>>>> Hi,
>>>>
>>>> the problem is: when I do the clibration at the clibration point
>>> which is 230V/ 10A/ 60 the meter displays the readings correct. when I
>>> adjusted the source to supply 230V/10A/0 phase shift, if found the
>>> displayed current change to 8.7A (although the clamp still reading 10A)
>>>> Moreover, when I turn the current source off 0A (while leaving the
>>> 230V), the chip sees current of 2.2A. So I tried to use the I1OFFSET
>>> to ajust the current but it did not work. So I activated the DC-REMove
>>> for the current but also it did not work.
>>>> Finally, I removed the jumber which connects the current input and
>>> voltage input to the VSS. I clibrated again then I changed the source
>>> phase shift to 0 and this time the results was correct and the current
>>> stayed at 10A
>>>> But when I sourced 0A the meter displayed 407mA and I could not
>>> remove it with IOFFSET and when I disconnect the AC the meter
>>> displayed 42mA while it is running on battery)
>>>> my questions are:
>>>> 1-how can I offset this readings to 0A or is this a problem with the
>>> FE427 crosstalk?
>>>> 2- when should I connect the Voltage and current input to the GND
>>> and when I should leave them floating?
>>>> Sam Hadima
>>>>
>>>> --- In m...@yahoogroups.com ,
>>> "old_cow_yellow" wrote:
>>>>> I agree with you.
>>>>>
>>>>> The ESP430 module does have some hardware features to facilitate
>>> calibration. The firmware should utilize these features to calibrate
>>> the sensors.
>>>>> --- In m...@yahoogroups.com ,
>>> Augusto Einsfeldt wrote:
>>>>>> OCY, he seems to want to calibrate his application (he wants PHASE
>>>>>> calibration).
>>>>>> So, it also means he doesn't know what he is doing and how the
>>>>>> application works.
>>>>>> Therefore, he must study the application and the mathematics
>>>>>> necessary for a power rail single phase meter... before asking this
>>>>>> kind of question...
>>>>>> -Augusto
>>>>>> On Qua 09/09/09 18:46 , "old_cow_yellow" old_cow_yellow@
>>>>>> sent:
>>>>>> The MSP430FE427 data-sheet says very little about calibration.
>>>>>> Which Application Note did you read?
>>>>>> Did you read the ESP430 Peripheral Modules User's Manual?
>>>>>> --- In m...@yahoogroups.com ,
>>> "smhhadima" ..> wrote:
>>>>>>> I could not calibrate the MSP430FE427.
>>>>>>> As I'm reading the datasheet, I noticed that at the calibration
>>>>>> section there was nothing about the PHASE correction; only it adjust
>>>>>> the GAIN correction and the OFFSET.
>>>>>>> and overall the datasheet and the application note are note clear
>>>>>> to me.
>>>>>>> did anyone succeed in calibrating or using the MSP430FE427 chip in
>>>>>> designing a single phase meter?
>>>>>>
>>>>>>
>>>>>> [Non-text portions of this message have been removed]
>>>>>>
>>>>
>>>>
>>>>
>>>> ------------------------------------
>>>>
>>>>
>>>>
>>>>



(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )

Fact, if the energy meter is working correctly and the magnitude of the
input current is kept constant the energy meter's current reading will
not change when the phase relationship between the applied voltage and
current is varied. The obvious in this case means looking for a bug in
the code. Although the bug in the code may not be obvious. The fact
that you got a reading of 8.66 instead of 10 may or may not help you
find a bug in the code.

Another thing you might try is first calibrate the energy meter with the
current and voltage in phase. Then vary the phase of the current to see
how the current measurement changes with phase. Do this at more than
one point. Making a change frequently leads to an insight when trouble
shooting.

Howard
OneStone wrote:
>
>
> Sin(60)=0.8660 * 10 = 8.66 ~ 8.7. You've calibrated with a 60 degree
> phase shift, depending on how you are processing the data later you
> cannot simply ignore this. To me this number jumps out from the page. It
> may turn out to be irrelevant, but when all else sems to fail look for
> the obvious
>
> Al
>
> smhhadima wrote:
> > 240V/ 10A/ 60Phase shift (PF=.5)
> > Sorry for not beenig clear
> > --- In m...@yahoogroups.com ,
> Howard Hansen wrote:
> >> Some thing is suspicious. Changing the phase relationship between
> >> current and voltage shouldn't affect the value of a current reading
> when
> >> the amplitude of the current is held constant. Yes changing the phase
> >> relationship will change the power relationship.
> >>
> >> What does 60 in "230V/10A/60" stand for? Does 60 here mean 60
> cycles or
> >> does it mean 60 degrees?
> >>
> >> Howard
> >>
> >>
> >> OneStone wrote:
> >>>
> >>>
> >>> HINT - What trigonometric value of a reading that changed between your
> >>> examples, rounded to 2 figures, is 0.87.
> >>>
> >>> Al
> >>>
> >>> smhhadima wrote:
> >>>> Hi,
> >>>>
> >>>> the problem is: when I do the clibration at the clibration point
> >>> which is 230V/ 10A/ 60 the meter displays the readings correct.
> when I
> >>> adjusted the source to supply 230V/10A/0 phase shift, if found the
> >>> displayed current change to 8.7A (although the clamp still reading
> 10A)
> >>>> Moreover, when I turn the current source off 0A (while leaving the
> >>> 230V), the chip sees current of 2.2A. So I tried to use the I1OFFSET
> >>> to ajust the current but it did not work. So I activated the
> DC-REMove
> >>> for the current but also it did not work.
> >>>> Finally, I removed the jumber which connects the current input and
> >>> voltage input to the VSS. I clibrated again then I changed the source
> >>> phase shift to 0 and this time the results was correct and the
> current
> >>> stayed at 10A
> >>>> But when I sourced 0A the meter displayed 407mA and I could not
> >>> remove it with IOFFSET and when I disconnect the AC the meter
> >>> displayed 42mA while it is running on battery)
> >>>> my questions are:
> >>>> 1-how can I offset this readings to 0A or is this a problem with the
> >>> FE427 crosstalk?
> >>>> 2- when should I connect the Voltage and current input to the GND
> >>> and when I should leave them floating?
> >>>> Sam Hadima
> >>>>
> >>>> --- In m...@yahoogroups.com
> ,
> >>> "old_cow_yellow" wrote:
> >>>>> I agree with you.
> >>>>
------------------------------------



(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )

Still, the OP seems to be working with a demo board for the SLAA203C
application note and thinks it is like a reference design (where all
things are solved and delivered).
He seems to think that someone in the list, who would already played
with the same demo board and application, would give him the hints to
understand the measurements. He also seems not understand how the
system works and how to evaluate what would produce these values.
So, the easiest way to have it solved is to contact his prefered
distributor and ask for FAE help. They will ask TI and TI's FAE will
give him a solution... of course, in case he is working in a companhy
that wants to produce some thousands of power meters.
If he is a student trying to solve a homework then he can try on TI
web site for technical help. They are quite nice even for students.
But, as a student, the best way for him would be study the software
and all related material he can put his hands on.
Otherwise he is wasting his own time (and everyone else).
-Augusto
On Sex 11/09/09 12:01 , Howard Hansen h...@att.net sent:
Fact, if the energy meter is working correctly and the magnitude of
the
input current is kept constant the energy meter's current reading
will
not change when the phase relationship between the applied voltage
and
current is varied. The obvious in this case means looking for a bug
in
the code. Although the bug in the code may not be obvious. The fact
that you got a reading of 8.66 instead of 10 may or may not help you

find a bug in the code.
Another thing you might try is first calibrate the energy meter with
the
current and voltage in phase. Then vary the phase of the current to
see
how the current measurement changes with phase. Do this at more than

one point. Making a change frequently leads to an insight when
trouble
shooting.
Howard
OneStone wrote:
>
>
> Sin(60)=0.8660 * 10 = 8.66 ~ 8.7. You've calibrated with a 60
degree
> phase shift, depending on how you are processing the data later
you
> cannot simply ignore this. To me this number jumps out from the
page. It
> may turn out to be irrelevant, but when all else sems to fail look
for
> the obvious
>
> Al
>
> smhhadima wrote:
> > 240V/ 10A/ 60Phase shift (PF=.5)
> > Sorry for not beenig clear
> > --- In m...@yahoogroups.com ,
> Howard Hansen
-------------------------
wrote:
> >> Some thing is suspicious. Changing the phase relationship
between
> >> current and voltage shouldn't affect the value of a current
reading
> when
> >> the amplitude of the current is held constant. Yes changing the
phase
> >> relationship will change the power relationship.
> >>
> >> What does 60 in "230V/10A/60" stand for? Does 60 here mean 60
> cycles or
> >> does it mean 60 degrees?
> >>
> >> Howard
> >>
> >>
> >> OneStone wrote:
> >>>
> >>>
> >>> HINT - What trigonometric value of a reading that changed
between your
> >>> examples, rounded to 2 figures, is 0.87.
> >>>
> >>> Al
> >>>
> >>> smhhadima wrote:
> >>>> Hi,
> >>>>
> >>>> the problem is: when I do the clibration at the clibration
point
> >>> which is 230V/ 10A/ 60 the meter displays the readings
correct.
> when I
> >>> adjusted the source to supply 230V/10A/0 phase shift, if found
the
> >>> displayed current change to 8.7A (although the clamp still
reading
> 10A)
> >>>> Moreover, when I turn the current source off 0A (while
leaving the
> >>> 230V), the chip sees current of 2.2A. So I tried to use the
I1OFFSET
> >>> to ajust the current but it did not work. So I activated the
> DC-REMove
> >>> for the current but also it did not work.
> >>>> Finally, I removed the jumber which connects the current
input and
> >>> voltage input to the VSS. I clibrated again then I changed the
source
> >>> phase shift to 0 and this time the results was correct and the

> current
> >>> stayed at 10A
> >>>> But when I sourced 0A the meter displayed 407mA and I could
not
> >>> remove it with IOFFSET and when I disconnect the AC the meter
> >>> displayed 42mA while it is running on battery)
> >>>> my questions are:
> >>>> 1-how can I offset this readings to 0A or is this a problem
with the
> >>> FE427 crosstalk?
> >>>> 2- when should I connect the Voltage and current input to the
GND
> >>> and when I should leave them floating?
> >>>> Sam Hadima
> >>>>
> >>>> --- In m...@yahoogroups.com
> ,
> >>> "old_cow_yellow"

> wrote:
> >>>>> I agree with you.
> >>>>>
>

[Non-text portions of this message have been removed]

------------------------------------



(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )

does anyone knows when, I calibrate the meter,
1-should I adjust the phase correction parameter first or I should adjust the GAIN and OFFSET first.
2- should I do my GAIN calculation based on the ACTIVE energy or on APPARENT energy?

the datasheet and the application note are not very clear to me

to Mr. Augusto: please try to be nice when you leave a comment about someone otherwise your help and your comments are not welcomed!

--- In m...@yahoogroups.com, Augusto Einsfeldt wrote:
>
>
> Still, the OP seems to be working with a demo board for the SLAA203C
> application note and thinks it is like a reference design (where all
> things are solved and delivered).
> He seems to think that someone in the list, who would already played
> with the same demo board and application, would give him the hints to
> understand the measurements. He also seems not understand how the
> system works and how to evaluate what would produce these values.
> So, the easiest way to have it solved is to contact his prefered
> distributor and ask for FAE help. They will ask TI and TI's FAE will
> give him a solution... of course, in case he is working in a companhy
> that wants to produce some thousands of power meters.
> If he is a student trying to solve a homework then he can try on TI
> web site for technical help. They are quite nice even for students.
> But, as a student, the best way for him would be study the software
> and all related material he can put his hands on.
> Otherwise he is wasting his own time (and everyone else).
> -Augusto
> On Sex 11/09/09 12:01 , Howard Hansen hrhan@... sent:
> Fact, if the energy meter is working correctly and the magnitude of
> the
> input current is kept constant the energy meter's current reading
> will
> not change when the phase relationship between the applied voltage
> and
> current is varied. The obvious in this case means looking for a bug
> in
> the code. Although the bug in the code may not be obvious. The fact
> that you got a reading of 8.66 instead of 10 may or may not help you
>
> find a bug in the code.
> Another thing you might try is first calibrate the energy meter with
> the
> current and voltage in phase. Then vary the phase of the current to
> see
> how the current measurement changes with phase. Do this at more than
>
> one point. Making a change frequently leads to an insight when
> trouble
> shooting.
> Howard
> OneStone wrote:
> >
> >
> > Sin(60)=0.8660 * 10 = 8.66 ~ 8.7. You've calibrated with a 60
> degree
> > phase shift, depending on how you are processing the data later
> you
> > cannot simply ignore this. To me this number jumps out from the
> page. It
> > may turn out to be irrelevant, but when all else sems to fail look
> for
> > the obvious
> >
> > Al
> >
> > smhhadima wrote:
> > > 240V/ 10A/ 60Phase shift (PF=.5)
> > > Sorry for not beenig clear
> > > --- In m...@yahoogroups.com ,
> > Howard Hansen
> -------------------------
> wrote:
> > >> Some thing is suspicious. Changing the phase relationship
> between
> > >> current and voltage shouldn't affect the value of a current
> reading
> > when
> > >> the amplitude of the current is held constant. Yes changing the
> phase
> > >> relationship will change the power relationship.
> > >>
> > >> What does 60 in "230V/10A/60" stand for? Does 60 here mean 60
> > cycles or
> > >> does it mean 60 degrees?
> > >>
> > >> Howard
> > >>
> > >>
> > >> OneStone wrote:
> > >>>
> > >>>
> > >>> HINT - What trigonometric value of a reading that changed
> between your
> > >>> examples, rounded to 2 figures, is 0.87.
> > >>>
> > >>> Al
> > >>>
> > >>> smhhadima wrote:
> > >>>> Hi,
> > >>>>
> > >>>> the problem is: when I do the clibration at the clibration
> point
> > >>> which is 230V/ 10A/ 60 the meter displays the readings
> correct.
> > when I
> > >>> adjusted the source to supply 230V/10A/0 phase shift, if found
> the
> > >>> displayed current change to 8.7A (although the clamp still
> reading
> > 10A)
> > >>>> Moreover, when I turn the current source off 0A (while
> leaving the
> > >>> 230V), the chip sees current of 2.2A. So I tried to use the
> I1OFFSET
> > >>> to ajust the current but it did not work. So I activated the
> > DC-REMove
> > >>> for the current but also it did not work.
> > >>>> Finally, I removed the jumber which connects the current
> input and
> > >>> voltage input to the VSS. I clibrated again then I changed the
> source
> > >>> phase shift to 0 and this time the results was correct and the
>
> > current
> > >>> stayed at 10A
> > >>>> But when I sourced 0A the meter displayed 407mA and I could
> not
> > >>> remove it with IOFFSET and when I disconnect the AC the meter
> > >>> displayed 42mA while it is running on battery)
> > >>>> my questions are:
> > >>>> 1-how can I offset this readings to 0A or is this a problem
> with the
> > >>> FE427 crosstalk?
> > >>>> 2- when should I connect the Voltage and current input to the
> GND
> > >>> and when I should leave them floating?
> > >>>> Sam Hadima
> > >>>>
> > >>>> --- In m...@yahoogroups.com
> > ,
> > >>> "old_cow_yellow"
>
> > wrote:
> > >>>>> I agree with you.
> > >>>>>
> >
>
>
> [Non-text portions of this message have been removed]
>
------------------------------------



(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )

To make sure we are looking at the same document please specify the
documents numbers you are using. If the documents you are using are
anything like slaa203c.pdf than it is not surprising you are getting
inconsistent results when calibrating an energy meter. It is also
obvious I was all wet when I said there was a bug in the code. More
likely the problem is a poorly written calibration procedure supplied by TI.

Howard
smhhadima wrote:
>
>
> does anyone knows when, I calibrate the meter,
> 1-should I adjust the phase correction parameter first or I should
> adjust the GAIN and OFFSET first.
> 2- should I do my GAIN calculation based on the ACTIVE energy or on
> APPARENT energy?
>
> the datasheet and the application note are not very clear to me
>
> to Mr. Augusto: please try to be nice when you leave a comment about
> someone otherwise your help and your comments are not welcomed!
>
> --- In m...@yahoogroups.com ,
> Augusto Einsfeldt wrote:
> >
> >
> > Still, the OP seems to be working with a demo board for the SLAA203C
> > application note and thinks it is like a reference design (where all
> > things are solved and delivered).
> > He seems to think that someone in the list, who would already played
> > with the same demo board and application, would give him the hints to
> > understand the measurements. He also seems not understand how the
> > system works and how to evaluate what would produce these values.
> > So, the easiest way to have it solved is to contact his prefered
> > distributor and ask for FAE help. They will ask TI and TI's FAE will
> > give him a solution... of course, in case he is working in a companhy
> > that wants to produce some thousands of power meters.
> > If he is a student trying to solve a homework then he can try on TI
> > web site for technical help. They are quite nice even for students.
> > But, as a student, the best way for him would be study the software
> > and all related material he can put his hands on.
> > Otherwise he is wasting his own time (and everyone else).
> > -Augusto
> > On Sex 11/09/09 12:01 , Howard Hansen hrhan@... sent:
> > Fact, if the energy meter is working correctly and the magnitude of
> > the
> > input current is kept constant the energy meter's current reading
> > will
> > not change when the phase relationship between the applied voltage
> > and
> > current is varied. The obvious in this case means looking for a bug
> > in
> > the code. Although the bug in the code may not be obvious. The fact
> > that you got a reading of 8.66 instead of 10 may or may not help you
> >
> > find a bug in the code.
> > Another thing you might try is first calibrate the energy meter with
> > the
> > current and voltage in phase. Then vary the phase of the current to
> > see
> > how the current measurement changes with phase. Do this at more than
> >
> > one point. Making a change frequently leads to an insight when
> > trouble
> > shooting.
> > Howard
> > OneStone wrote:
> > >
> > >
> > > Sin(60)=0.8660 * 10 = 8.66 ~ 8.7. You've calibrated with a 60
> > degree
> > > phase shift, depending on how you are processing the data later
> > you
> > > cannot simply ignore this. To me this number jumps out from the
> > page. It
> > > may turn out to be irrelevant, but when all else sems to fail look
> > for
> > > the obvious
> > >
> > > Al
> > >
> > > smhhadima wrote:
> > > > 240V/ 10A/ 60Phase shift (PF=.5)
> > > > Sorry for not beenig clear
> > > > --- In m...@yahoogroups.com ,
> > > Howard Hansen
> > -------------------------
> > wrote:
> > > >> Some thing is suspicious. Changing the phase relationship
> > between
> > > >> current and voltage shouldn't affect the value of a current
> > reading
> > > when
> > > >> the amplitude of the current is held constant. Yes changing the
> > phase
> > > >> relationship will change the power relationship.
> > > >>
> > > >> What does 60 in "230V/10A/60" stand for? Does 60 here mean 60
> > > cycles or
> > > >> does it mean 60 degrees?
> > > >>
> > > >> Howard
> > > >>
> > > >>
> > > >> OneStone wrote:
> > > >>>
> > > >>>
> > > >>> HINT - What trigonometric value of a reading that changed
> > between your
> > > >>> examples, rounded to 2 figures, is 0.87.
> > > >>>
> > > >>> Al
> > > >>>
> > > >>> smhhadima wrote:
> > > >>>> Hi,
> > > >>>>
> > > >>>> the problem is: when I do the clibration at the clibration
> > point
> > > >>> which is 230V/ 10A/ 60 the meter displays the readings
> > correct.
> > > when I
> > > >>> adjusted the source to supply 230V/10A/0 phase shift, if found
> > the
> > > >>> displayed current change to 8.7A (although the clamp still
> > reading
> > > 10A)
> > > >>>> Moreover, when I turn the current source off 0A (while
> > leaving the
> > > >>> 230V), the chip sees current of 2.2A. So I tried to use the
> > I1OFFSET
> > > >>> to ajust the current but it did not work. So I activated the
> > > DC-REMove
> > > >>> for the current but also it did not work.
> > > >>>> Finally, I removed the jumber which connects the current
> > input and
> > > >>> voltage input to the VSS. I clibrated again then I changed the
> > source
> > > >>> phase shift to 0 and this time the results was correct and the
> >
> > > current
> > > >>> stayed at 10A
> > > >>>> But when I sourced 0A the meter displayed 407mA and I could
> > not
> > > >>> remove it with IOFFSET and when I disconnect the AC the meter
> > > >>> displayed 42mA while it is running on battery)
> > > >>>> my questions are:
> > > >>>> 1-how can I offset this readings to 0A or is this a problem
> > with the
> > > >>> FE427 crosstalk?
> > > >>>> 2- when should I connect the Voltage and current input to the
> > GND
> > > >>> and when I should leave them floating?
> > > >>>> Sam Hadima
> > > >>>>
> > > >>>> --- In m...@yahoogroups.com
> > > ,
> > > >>> "old_cow_yellow"
> >
> > > wrote:
> > > >>>>> I agree with you.
> > > >>>>>
> > >
> >
> >
> > [Non-text portions of this message have been removed]
> >

------------------------------------



(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )

Mr. Sam, I did not meant to be rude. The way you posted your
questions did show how shallow is your knowledge in this matter. An
application note is normally no more then an example of how can you
do something. It may work on any hardware or may work on the author's
hardware/software only. A reference design would be a more consistent
system where you could rely on the information provided to work on
any "copy of the system".
You have to understand how the software works and then you will
understand how the calibration procedure works.
Asking about the calibration procedure here would give you results
only if someone already made it to work. No one has answered this
way, yet. So you are wasting your time if you do not go deep in the
software and other documents you can grab regarding this kind of
system.
The FE427 does not make the meter by itself. The software does. And
the application may work well only in some cases. For instance, it
may work with phase at 60 degrees and do not work in any other angle,
even with resistive load (phase in 0 degrees).
Maybe an example gives you what I mean: I did use the TI's floating
point math library once. It is an application note based and work
well for extended FP. Short FP, with 4 bytes, should also work but
there are several bugs. So, the authors did test the extended but did
not test (in detail) the short type. I did read all source files and
follow what every single routine does to understand what was
happening. Then I fixed the library and now it works as a charm. You
have to understand what you are working on. Even before asking help.
-Augusto
On S=C3=A1b 12/09/09 12:09 , "smhhadima" s...@yahoo.com sent:
does anyone knows when, I calibrate the meter,=20
1-should I adjust the phase correction parameter first or I should
adjust the GAIN and OFFSET first.
2- should I do my GAIN calculation based on the ACTIVE energy or on
APPARENT energy?
the datasheet and the application note are not very clear to me
to Mr. Augusto: please try to be nice when you leave a comment about
someone otherwise your help and your comments are not welcomed!
--- In m...@yahoogroups.com, Augusto Einsfeldt wrote:
>
>=20=20
> Still, the OP seems to be working with a demo board for the
SLAA203C
> application note and thinks it is like a reference design (where
all
> things are solved and delivered).
> He seems to think that someone in the list, who would already
played
> with the same demo board and application, would give him the hints
to
> understand the measurements. He also seems not understand how the
> system works and how to evaluate what would produce these values.
> So, the easiest way to have it solved is to contact his prefered
> distributor and ask for FAE help. They will ask TI and TI's FAE
will
> give him a solution... of course, in case he is working in a
companhy
> that wants to produce some thousands of power meters.
> If he is a student trying to solve a homework then he can try on
TI
> web site for technical help. They are quite nice even for
students.
> But, as a student, the best way for him would be study the
software
> and all related material he can put his hands on.
> Otherwise he is wasting his own time (and everyone else).
> -Augusto
> On Sex 11/09/09 12:01 , Howard Hansen hrhan@... sent:
> Fact, if the energy meter is working correctly and the magnitude
of
> the=20
> input current is kept constant the energy meter's current reading
> will=20
> not change when the phase relationship between the applied
voltage
> and=20
> current is varied. The obvious in this case means looking for a
bug
> in=20
> the code. Although the bug in the code may not be obvious. The
fact=20
> that you got a reading of 8.66 instead of 10 may or may not help
you
>=20
> find a bug in the code.=20
> Another thing you might try is first calibrate the energy meter
with
> the=20
> current and voltage in phase. Then vary the phase of the current
to
> see=20
> how the current measurement changes with phase. Do this at more
than
>=20
> one point. Making a change frequently leads to an insight when
> trouble=20
> shooting.
> Howard
> OneStone wrote:
> >=20
> >
> > Sin(60)=3D0.8660 * 10 =3D 8.66 ~ 8.7. You've calibrated with a 60
> degree
> > phase shift, depending on how you are processing the data later
> you
> > cannot simply ignore this. To me this number jumps out from the
> page. It
> > may turn out to be irrelevant, but when all else sems to fail
look
> for
> > the obvious
> >
> > Al
> >
> > smhhadima wrote:
> > > 240V/ 10A/ 60Phase shift (PF=3D.5)
> > > Sorry for not beenig clear
> > > --- In m...@yahoogroups.com ,=20
> > Howard Hansen=20
> -------------------------
> wrote:
> > >> Some thing is suspicious. Changing the phase relationship
> between
> > >> current and voltage shouldn't affect the value of a current
> reading=20
> > when
> > >> the amplitude of the current is held constant. Yes changing
the
> phase
> > >> relationship will change the power relationship.
> > >>
> > >> What does 60 in "230V/10A/60" stand for? Does 60 here mean
60=20
> > cycles or
> > >> does it mean 60 degrees?
> > >>
> > >> Howard
> > >>
> > >>
> > >> OneStone wrote:
> > >>>
> > >>>
> > >>> HINT - What trigonometric value of a reading that changed
> between your
> > >>> examples, rounded to 2 figures, is 0.87.
> > >>>
> > >>> Al
> > >>>
> > >>> smhhadima wrote:
> > >>>> Hi,
> > >>>>
> > >>>> the problem is: when I do the clibration at the clibration
> point
> > >>> which is 230V/ 10A/ 60 the meter displays the readings
> correct.=20
> > when I
> > >>> adjusted the source to supply 230V/10A/0 phase shift, if
found
> the
> > >>> displayed current change to 8.7A (although the clamp still
> reading=20
> > 10A)
> > >>>> Moreover, when I turn the current source off 0A (while
> leaving the
> > >>> 230V), the chip sees current of 2.2A. So I tried to use the
> I1OFFSET
> > >>> to ajust the current but it did not work. So I activated
the=20
> > DC-REMove
> > >>> for the current but also it did not work.
> > >>>> Finally, I removed the jumber which connects the current
> input and
> > >>> voltage input to the VSS. I clibrated again then I changed
the
> source
> > >>> phase shift to 0 and this time the results was correct and
the
>=20
> > current
> > >>> stayed at 10A
> > >>>> But when I sourced 0A the meter displayed 407mA and I
could
> not
> > >>> remove it with IOFFSET and when I disconnect the AC the
meter
> > >>> displayed 42mA while it is running on battery)
> > >>>> my questions are:
> > >>>> 1-how can I offset this readings to 0A or is this a
problem
> with the
> > >>> FE427 crosstalk?
> > >>>> 2- when should I connect the Voltage and current input to
the
> GND
> > >>> and when I should leave them floating?
> > >>>> Sam Hadima
> > >>>>
> > >>>> --- In m...@yahoogroups.com=20=20
> > ,
> > >>> "old_cow_yellow"=20
>=20
> > wrote:
> > >>>>> I agree with you.
> > >>>>>
> >
>=20=20=20=20=20=20=20=20=20=20=20=20=20
>=20
> [Non-text portions of this message have been removed]
>
=
=20
[Non-text portions of this message have been removed]

------------------------------------



(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )

There are plenty of people that know to do plenty of things. Not limited to "calibrate THE meter". Or "THE application note".

--- In m...@yahoogroups.com, "smhhadima" wrote:
>
> does anyone knows when, I calibrate the meter,
> 1-should I adjust the phase correction parameter first or I should adjust the GAIN and OFFSET first.
> 2- should I do my GAIN calculation based on the ACTIVE energy or on APPARENT energy?
>
> the datasheet and the application note are not very clear to me
>
> to Mr. Augusto: please try to be nice when you leave a comment about someone otherwise your help and your comments are not welcomed!
>
> --- In m...@yahoogroups.com, Augusto Einsfeldt wrote:
> >
> >
> > Still, the OP seems to be working with a demo board for the SLAA203C
> > application note and thinks it is like a reference design (where all
> > things are solved and delivered).
> > He seems to think that someone in the list, who would already played
> > with the same demo board and application, would give him the hints to
> > understand the measurements. He also seems not understand how the
> > system works and how to evaluate what would produce these values.
> > So, the easiest way to have it solved is to contact his prefered
> > distributor and ask for FAE help. They will ask TI and TI's FAE will
> > give him a solution... of course, in case he is working in a companhy
> > that wants to produce some thousands of power meters.
> > If he is a student trying to solve a homework then he can try on TI
> > web site for technical help. They are quite nice even for students.
> > But, as a student, the best way for him would be study the software
> > and all related material he can put his hands on.
> > Otherwise he is wasting his own time (and everyone else).
> > -Augusto
> > On Sex 11/09/09 12:01 , Howard Hansen hrhan@ sent:
> > Fact, if the energy meter is working correctly and the magnitude of
> > the
> > input current is kept constant the energy meter's current reading
> > will
> > not change when the phase relationship between the applied voltage
> > and
> > current is varied. The obvious in this case means looking for a bug
> > in
> > the code. Although the bug in the code may not be obvious. The fact
> > that you got a reading of 8.66 instead of 10 may or may not help you
> >
> > find a bug in the code.
> > Another thing you might try is first calibrate the energy meter with
> > the
> > current and voltage in phase. Then vary the phase of the current to
> > see
> > how the current measurement changes with phase. Do this at more than
> >
> > one point. Making a change frequently leads to an insight when
> > trouble
> > shooting.
> > Howard
> > OneStone wrote:
> > >
> > >
> > > Sin(60)=0.8660 * 10 = 8.66 ~ 8.7. You've calibrated with a 60
> > degree
> > > phase shift, depending on how you are processing the data later
> > you
> > > cannot simply ignore this. To me this number jumps out from the
> > page. It
> > > may turn out to be irrelevant, but when all else sems to fail look
> > for
> > > the obvious
> > >
> > > Al
> > >
> > > smhhadima wrote:
> > > > 240V/ 10A/ 60Phase shift (PF=.5)
> > > > Sorry for not beenig clear
> > > > --- In m...@yahoogroups.com ,
> > > Howard Hansen
> > -------------------------
> > wrote:
> > > >> Some thing is suspicious. Changing the phase relationship
> > between
> > > >> current and voltage shouldn't affect the value of a current
> > reading
> > > when
> > > >> the amplitude of the current is held constant. Yes changing the
> > phase
> > > >> relationship will change the power relationship.
> > > >>
> > > >> What does 60 in "230V/10A/60" stand for? Does 60 here mean 60
> > > cycles or
> > > >> does it mean 60 degrees?
> > > >>
> > > >> Howard
> > > >>
> > > >>
> > > >> OneStone wrote:
> > > >>>
> > > >>>
> > > >>> HINT - What trigonometric value of a reading that changed
> > between your
> > > >>> examples, rounded to 2 figures, is 0.87.
> > > >>>
> > > >>> Al
> > > >>>
> > > >>> smhhadima wrote:
> > > >>>> Hi,
> > > >>>>
> > > >>>> the problem is: when I do the clibration at the clibration
> > point
> > > >>> which is 230V/ 10A/ 60 the meter displays the readings
> > correct.
> > > when I
> > > >>> adjusted the source to supply 230V/10A/0 phase shift, if found
> > the
> > > >>> displayed current change to 8.7A (although the clamp still
> > reading
> > > 10A)
> > > >>>> Moreover, when I turn the current source off 0A (while
> > leaving the
> > > >>> 230V), the chip sees current of 2.2A. So I tried to use the
> > I1OFFSET
> > > >>> to ajust the current but it did not work. So I activated the
> > > DC-REMove
> > > >>> for the current but also it did not work.
> > > >>>> Finally, I removed the jumber which connects the current
> > input and
> > > >>> voltage input to the VSS. I clibrated again then I changed the
> > source
> > > >>> phase shift to 0 and this time the results was correct and the
> >
> > > current
> > > >>> stayed at 10A
> > > >>>> But when I sourced 0A the meter displayed 407mA and I could
> > not
> > > >>> remove it with IOFFSET and when I disconnect the AC the meter
> > > >>> displayed 42mA while it is running on battery)
> > > >>>> my questions are:
> > > >>>> 1-how can I offset this readings to 0A or is this a problem
> > with the
> > > >>> FE427 crosstalk?
> > > >>>> 2- when should I connect the Voltage and current input to the
> > GND
> > > >>> and when I should leave them floating?
> > > >>>> Sam Hadima
> > > >>>>
> > > >>>> --- In m...@yahoogroups.com
> > > ,
> > > >>> "old_cow_yellow"
> >
> > > wrote:
> > > >>>>> I agree with you.
> > > >>>>>
> > >
> >
> >
> > [Non-text portions of this message have been removed]
>

------------------------------------



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I am using the slaa203c.pdf and SLAU134B.pdf
and as you know the calibation procedure is poorly written
and I cannot figure out the right procedures
--- In m...@yahoogroups.com, Howard Hansen wrote:
>
> To make sure we are looking at the same document please specify the
> documents numbers you are using. If the documents you are using are
> anything like slaa203c.pdf than it is not surprising you are getting
> inconsistent results when calibrating an energy meter. It is also
> obvious I was all wet when I said there was a bug in the code. More
> likely the problem is a poorly written calibration procedure supplied by TI.
>
> Howard
> smhhadima wrote:
> >
> >
> > does anyone knows when, I calibrate the meter,
> > 1-should I adjust the phase correction parameter first or I should
> > adjust the GAIN and OFFSET first.
> > 2- should I do my GAIN calculation based on the ACTIVE energy or on
> > APPARENT energy?
> >
> > the datasheet and the application note are not very clear to me
> >
> > to Mr. Augusto: please try to be nice when you leave a comment about
> > someone otherwise your help and your comments are not welcomed!
> >
> > --- In m...@yahoogroups.com ,
> > Augusto Einsfeldt wrote:
> > >
> > >
> > > Still, the OP seems to be working with a demo board for the SLAA203C
> > > application note and thinks it is like a reference design (where all
> > > things are solved and delivered).
> > > He seems to think that someone in the list, who would already played
> > > with the same demo board and application, would give him the hints to
> > > understand the measurements. He also seems not understand how the
> > > system works and how to evaluate what would produce these values.
> > > So, the easiest way to have it solved is to contact his prefered
> > > distributor and ask for FAE help. They will ask TI and TI's FAE will
> > > give him a solution... of course, in case he is working in a companhy
> > > that wants to produce some thousands of power meters.
> > > If he is a student trying to solve a homework then he can try on TI
> > > web site for technical help. They are quite nice even for students.
> > > But, as a student, the best way for him would be study the software
> > > and all related material he can put his hands on.
> > > Otherwise he is wasting his own time (and everyone else).
> > > -Augusto
> > > On Sex 11/09/09 12:01 , Howard Hansen hrhan@ sent:
> > > Fact, if the energy meter is working correctly and the magnitude of
> > > the
> > > input current is kept constant the energy meter's current reading
> > > will
> > > not change when the phase relationship between the applied voltage
> > > and
> > > current is varied. The obvious in this case means looking for a bug
> > > in
> > > the code. Although the bug in the code may not be obvious. The fact
> > > that you got a reading of 8.66 instead of 10 may or may not help you
> > >
> > > find a bug in the code.
> > > Another thing you might try is first calibrate the energy meter with
> > > the
> > > current and voltage in phase. Then vary the phase of the current to
> > > see
> > > how the current measurement changes with phase. Do this at more than
> > >
> > > one point. Making a change frequently leads to an insight when
> > > trouble
> > > shooting.
> > > Howard
> > > OneStone wrote:
> > > >
> > > >
> > > > Sin(60)=0.8660 * 10 = 8.66 ~ 8.7. You've calibrated with a 60
> > > degree
> > > > phase shift, depending on how you are processing the data later
> > > you
> > > > cannot simply ignore this. To me this number jumps out from the
> > > page. It
> > > > may turn out to be irrelevant, but when all else sems to fail look
> > > for
> > > > the obvious
> > > >
> > > > Al
> > > >
> > > > smhhadima wrote:
> > > > > 240V/ 10A/ 60Phase shift (PF=.5)
> > > > > Sorry for not beenig clear
> > > > > --- In m...@yahoogroups.com ,
> > > > Howard Hansen
> > > -------------------------
> > > wrote:
> > > > >> Some thing is suspicious. Changing the phase relationship
> > > between
> > > > >> current and voltage shouldn't affect the value of a current
> > > reading
> > > > when
> > > > >> the amplitude of the current is held constant. Yes changing the
> > > phase
> > > > >> relationship will change the power relationship.
> > > > >>
> > > > >> What does 60 in "230V/10A/60" stand for? Does 60 here mean 60
> > > > cycles or
> > > > >> does it mean 60 degrees?
> > > > >>
> > > > >> Howard
> > > > >>
> > > > >>
> > > > >> OneStone wrote:
> > > > >>>
> > > > >>>
> > > > >>> HINT - What trigonometric value of a reading that changed
> > > between your
> > > > >>> examples, rounded to 2 figures, is 0.87.
> > > > >>>
> > > > >>> Al
> > > > >>>
> > > > >>> smhhadima wrote:
> > > > >>>> Hi,
> > > > >>>>
> > > > >>>> the problem is: when I do the clibration at the clibration
> > > point
> > > > >>> which is 230V/ 10A/ 60 the meter displays the readings
> > > correct.
> > > > when I
> > > > >>> adjusted the source to supply 230V/10A/0 phase shift, if found
> > > the
> > > > >>> displayed current change to 8.7A (although the clamp still
> > > reading
> > > > 10A)
> > > > >>>> Moreover, when I turn the current source off 0A (while
> > > leaving the
> > > > >>> 230V), the chip sees current of 2.2A. So I tried to use the
> > > I1OFFSET
> > > > >>> to ajust the current but it did not work. So I activated the
> > > > DC-REMove
> > > > >>> for the current but also it did not work.
> > > > >>>> Finally, I removed the jumber which connects the current
> > > input and
> > > > >>> voltage input to the VSS. I clibrated again then I changed the
> > > source
> > > > >>> phase shift to 0 and this time the results was correct and the
> > >
> > > > current
> > > > >>> stayed at 10A
> > > > >>>> But when I sourced 0A the meter displayed 407mA and I could
> > > not
> > > > >>> remove it with IOFFSET and when I disconnect the AC the meter
> > > > >>> displayed 42mA while it is running on battery)
> > > > >>>> my questions are:
> > > > >>>> 1-how can I offset this readings to 0A or is this a problem
> > > with the
> > > > >>> FE427 crosstalk?
> > > > >>>> 2- when should I connect the Voltage and current input to the
> > > GND
> > > > >>> and when I should leave them floating?
> > > > >>>> Sam Hadima
> > > > >>>>
> > > > >>>> --- In m...@yahoogroups.com
> > > > ,
> > > > >>> "old_cow_yellow"
> > >
> > > > wrote:
> > > > >>>>> I agree with you.
> > > > >>>>>
> > > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
>

------------------------------------



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