How to write a VI to measure the difference between two analog inputs (voltage)

I'd like to measure the difference voltage between two analog inputs.
Could someone write me a VI for it, please?
I'm new with Labview....
Thanks a lot!!!

On the numeric palette, there is a function called subtract. As the
help for it says, it 'Computes the difference of the inputs.'.
Since
this is such a simple process, you need to provide some details on why
you can't do this. You can wire just about any data type into the
inputs. Post your code if you need further help.
Message Edited by Dennis Knutson on 04-05-2009 08:23 AM
Attachments:
Subtract.PNG ‏1 KB

Similar Messages

How can I measure the frequencies of two analog input signals simultaneously?

Hi
I have two AI signals, and I need to determine the frequencies of those signals. The frequencies range from 1-125Hz. I currently have a VI where I can sample one of the signals for 1 second (sampling at 300 Hz for 300 samples) and determine the frequency.
I need to read two signals at the same time and get both of the frequencies at the same time, but I can only figure out how to read them individually, so I can read one signal, then one second later I read the second one, then I read the first one again, then the sceond one, etc.. How can I read two signals simultaneously?
Thanks
Attachments:
FreqMeas11.vi ‏41 KB
FreqMeas11.PNG ‏18 KB

"at same time", this depends on the hardware, you can do as has been previously stated just set up a 2 channel acquisition and you will get 2 sampled waveforms back. Most hardware A/D as multiplexed and true simultaneous sampling is not done. At 125Hz this is not an issue unless you are interested in very small phase changes between the samples. just keep this in mind if you are expecting samples to be completly synchronized.
Paul
Paul Falkenstein
Coleman Technologies Inc.
CLA, CPI, AIA-Vision
Labview 4.0- 2013, RT, Vision, FPGA

How can I use counters to read the difference between two external pulse signals?

I generated a pulse signal and sent it to a sensor which in turn gives me a pulse signal back. I need to read the time from which the sent the signal goes high to the time that the signal is returned. How can I read this? the diagram is attached
Attachments:
Timing_Diagram1.doc ‏256 KB

There is vi called "Two Edge Separation Mesurement (NI-TIO).vi". In LV6.1 it is in "c:\...\LabVIEW 6.1\Examples\DAQ\Counter\ni-tio.llb".
Unfortunately this function has no timeout. This means that your program will hang on if there are no pulses. I have attached an improved version of this vi with a timeout(sorry for the french text in the description). There are also some other improvements like the calculation of the edge separation in seconds (not only clock counts).
This function will only work with NI-TIO cards (like 660x).
Attachments:
Two_Edge_Separation_Measurement_with_Timeout_(NI-TIO).vi ‏103 KB

How can I use counters to read the difference between two expernal pulse signals?

I generated a pulse signal and sent it to a sensor which in turn gives me a pulse signal back. I need to read the time from which the sent the signal goes high to the time that the signal is returned. How can I read this? the diagram is attached
Attachments:
Timing_Diagram1.doc ‏256 KB

Hello;
The way to accomplish that is by using one of the 660x boards, and configure the counter to do "Edge Separation Method".
That method will increment the counter event count value every time a pulse comes into its source input. The counters only increments between the rising edge of the aux line and the rising edge of the gate. The current value of the counter is read when the counter is finished or an error occurs. You need to wire the out pulse to the AUX line, and the return pulse to the gate line of the counter.
Hope this helps.
Filipe A.
Applications Engineer
National Instruments

How to get the difference between two date

Hello,
I want to know how to write a code the tell me the difference between two date, I am using
oracle.jbo.domain.Date
i have a rent date and return date so my code is
Date rent=(Date)nr.getAttrbute("RentDate"),ret=(Date)nr.getAttrbute("ReturnDate");
is there a way to know the difference in days between those two dates ?
Thanks

hi,
try this.....
DateFormat formatter = new SimpleDateFormat("E MMM dd HH:mm:ss Z yyyy");
Date date = (Date)formatter.parse(dateStr); //// dateStr <- from date value (that is string value)
Date dateto = (Date)formatter.parse(datetostr); //// datetostr <- to date value (to date getting from as a string)
Calendar cal = Calendar.getInstance();
cal.setTime(date);
Calendar calto = Calendar.getInstance();
calto.setTime(dateto);
fromDate = cal.get(Calendar.DATE) + "/" + (cal.get(Calendar.MONTH) + 1) + "/" + cal.get(Calendar.YEAR);
toDate = calto.get(Calendar.DATE) + "/" + (calto.get(Calendar.MONTH) + 1) + "/" + calto.get(Calendar.YEAR);
// System.out.println("from Date : " + fromDate);
if ((fromDate != null && toDate != null) && (date.compareTo(dateto) > -1) ) {
fc.addMessage("VacationQueryComponent", new FacesMessage(FacesMessage.SEVERITY_ERROR, "From Date cannot be lower than To Date", "From Date cannot be lower than To Date"));
fc.renderResponse();
thks.

How to get the difference between two columns in a column group

Hi All,
My first time here and really new to programming. I would like to get the difference between 2 columns that are inside
a column group.
Here is my sample table below: The Column Group is PeriodNumber and can only choose 2. like 1 and 2.. I would like to have a third row which will simply calculate the difference between the amounts in PeriodNumber 1 and 2.
PeriodNumber
Account 1 2
1) Cash 10,000 15,000
2) Receivables 12,000 11,500
3) Equipment 5,000 5,500
Total Assets 27,000 32,000

Hi yabgestopa,
From your description, you want to get the difference between two columns in a column group. After testing it in my environment, we can use custom code to achieve your requirement. For more details, you can refer to the following steps:
Copy the custom code below and paste it to your report. (Right-click report>Report Properties>Code)
Dim Shared Num1 As Integer
Dim shared Num2 As Integer
Public Function GetAmount(Amount as Integer, Type as String)
If Type = "1" Then
Num1=Amount
Else
Num2=Amount
End If
Return Amount
End Function
Public Function GetDif()
Return Num1-Num2
End function
Right-click the second column to insert a third column with Outside Group-Right.
Then use the expressions below in the matrix.
=Code.GetAmount(Fields!Amount.Value,Fields!PeriodNumber.Value)
=code.GetAmount(Sum(Fields!Amount.Value),Fields!PeriodNumber.Value)
=Code.GetDif()
The report looks like below.
If you have any questions, please feel free to ask.
Thanks,
Katherine Xiong
Katherine Xiong
TechNet Community Support

Java code to get the difference between two dates in days

Hi ppl,
I need to write a user defined function to get the difference between two date nodes, in days.Please help me out
regards,
Prashanth

Hi,
have a look at those two:
(How do I calculate the difference between two dates?)
http://joda-time.sourceforge.net/faq.html
Calculating the Difference Between Two Datetime Stamps
http://www.xmission.com/~goodhill/dates/deltaDates.html
Get difference in days
http://javaalmanac.com/egs/java.util/CompDates.html
Regards,
michal

Need to find the Difference between two table

Hello ,
I have stucked in program as below scenario:-
I have two tables of huge data of same structure in a same schema.I need to find the difference exact values in tables.
By using MINUS we can find the difference between two table ,i need to find the what exact difference in the there values with colunm and value at that column.
Example TableA
Col1 col2 col3 col4 col5.... col50
10 ABC 2001 EE 444 TT
40 XYZ 3002 RR 445 TT3
80 DEF 6005 YY 446 YY8
TableB
Col1 col2 col3 col4 col5.... col50
10 ABC 2001 EE 444 TT
40 XYZ 3002 RR 445 TT3
81 DEF 6005 Yu 447 YY8
I need to the out put like this :-
The Diffence between two table is
TableA.COL1=80 TableB.Col1=81, Different
TableA.Col4=YY TableB.col4=Yu,Different
TableA.Col5=446TableB.col5=447,Different
Please suggest me to write the pl/sql program for the same
thanx in advance
KK

Thanx friends for all your efforts
I have a sample code for the same,this will compare the two tables for single row in each table .
what r the modification needed for the multiple rows of values in the two tables??
Please suggest!!
CREATE OR REPLACE PROCEDURE test_compare
IS
TYPE t_col
IS
TABLE OF VARCHAR2 (30)
INDEX BY PLS_INTEGER;
l_col t_col;
j NUMBER := 0;
l_sql VARCHAR2 (2000);
col1 VARCHAR2 (30);
col2 VARCHAR2 (30);
val1 NUMBER;
val2 NUMBER;
status VARCHAR2 (30);
CURSOR c1
IS
SELECT column_id, column_name
FROM all_tab_columns
WHERE table_name = 'TEST1';
BEGIN
FOR i IN c1
LOOP
j := j + 1;
l_col (j) := i.column_name;
END LOOP;
FOR k IN 1 .. j
LOOP
l_sql :=
'SELECT '
|| ''''
|| l_col (k)
|| ''''
|| ', '
|| 'TEST2.'
|| l_col (k)
|| ', '
|| ''''
|| l_col (k)
|| ''''
|| ', '
|| 'TEST1.'
|| l_col (k )
|| ', '
|| 'DECODE(TEST2.'
|| l_col (k)
|| ' -TEST1.'
|| l_col (k)
|| ', 0, ''NO CHANGE'', ''CHANGED'') FROM TEST2, TEST1';
EXECUTE IMMEDIATE l_sql INTO col1, val1,col2, val2, status;
IF status = 'CHANGED'
THEN
DBMS_OUTPUT.put_line( 'TEST2.'
|| col1
|| '='
|| val1
|| ', TEST1.'
|| col2
|| '='
|| val2
|| ', '
|| status);
END IF;
END LOOP;
EXCEPTION
WHEN OTHERS
THEN
DBMS_OUTPUT.put_line ('Error:- ' || SQLERRM);
END;
/

Find the difference between two internal table

how can i see the difference between two interal tables?
The requirement is as follows
1. We have a transparent table, which stores the employee data with EMP ID as key.
2. We load the transp table data into a interal table (B).
3. We get data from legecy system as file and it gets loaded into another internal table (A) (this also has the same EMP ID key and this will have latest addition/update to those emplyees).
Now we need to seperate out these data into three interal table Inserted (I), Deleted (D) and Updated (U).
We want to do followign things
I = A - B
D = B - A
Both A and B will have around 40k records. Hence we are trying to avoid the looping.
Please suggest the best option for us.
Thank you in advance.
Raghavendra

>
RAGHAV URAL wrote:
> how can i see the difference between two interal tables?
> The requirement is as follows
>
> 1. We have a transparent table, which stores the employee data with EMP ID as key.
> 2. We load the transp table data into a interal table (B).
> 3. We get data from legecy system as file and it gets loaded into another internal table (A) (this also has the same EMP ID key and this will have latest addition/update to those emplyees).
>
> Now we need to seperate out these data into three interal table Inserted (I), Deleted (D) and Updated (U).
>
> We want to do followign things
> I = A - B
> D = B - A
>
> Both A and B will have around 40k records. Hence we are trying to avoid the looping.
>
> Please suggest the best option for us.
>
> Thank you in advance.
> Raghavendra
Hi Raghavendra,
Currently as of my knowledge, these operations are only possible through LOOPs. But LOOPign can be really fast here if you properly utilize the SORTING, READ with BINARY SEARCH and FIELD-SYMBOLS usage. I would say:-
Steps for Insert:-
SORT: A, B.
LOOP AT A ASSIGNING <WA_A>.
READ TABLE B WITH TABLE KEY key = <WA_A>-key BINARY SEARCH.
IF SY-SUBRC NE 0.
APPEND <WA_A> TO I.
ENDIF.
ENDLOOP.
Steps for Delete:-
SORT: A, B.
LOOP AT B ASSIGNING <WA_B>.
READ TABLE A WITH TABLE KEY key = <WA_B>-key BINARY SEARCH.
IF SY-SUBRC NE 0.
APPEND <WA_B> TO D.
ENDIF.
ENDLOOP.
Regards,
Ravi.

Find the difference between two columns in an ssrs matrix ? MSCRM

Hi All,
I am working in reporting part of our project (On-line MSCRM 2013) & in reporting services.
I am trying to create report using fetch xml based. Below is the snap what we required the result.
Kindly help me, how to get the difference in both column. (Its a matrix table where year is grouped).
We need difference between both year Like (Plan Revenue of 2013 & Plan Revenue of 2014 difference in Plan Revenue Diff section) and same for Actual
Revenue.
https://social.microsoft.com/Forums/en-US/054d5ca4-0d38-4dc6-84a8-88866cc228fe/find-the-difference-between-two-columns-in-an-ssrs-matrix-mscrm?forum=crmdevelopment
Thanks,
Mohammad Sharique

Hi Bro,
I used parametrized option for year and done the report,Currently we are getting values in Difference column now i want to show
that value in percentage. How can we show the percentage based on that value. Means i want to show the Difference in Percentage.
Kindly help me i tried but getting some issue. Below i am mentioning the code and snap with result.
Below expression using to showing Plan Revenue in Percentage for year.
=
Sum(IIF(Fields!new_year.Value =Parameters!StartYear.Value,cdec(Fields!new_planrevenueValue.Value/1000), cdec(0)))
- Sum(IIF(Fields!new_year.Value =Parameters!EndYear.Value,cdec(Fields!new_planrevenueValue.Value/1000), cdec(0)))
/IIF(Sum(IIF(Fields!new_year.Value = Parameters!StartYear.Value,cdec(Fields!new_planrevenueValue.Value/1000), cdec(0)))>0,
(Sum(IIF(Fields!new_year.Value = Parameters!StartYear.Value,cdec(Fields!new_planrevenueValue.Value/1000), cdec(0))))
,1)
)*100))
Result issue is as below in snap with highlighted in red colour.
Kindly help me on this issue also :)

Function Module to find the Difference between two times.

Hi All,
Wud you plz let me know the Function Module to find the Difference between two times.
Input Time1( Hours:Minutes) Time2 ( Hours:Minutes)
Need Output in Hours:Minutes only . ( No seconds Needed )
Ex :
Input :
       06:00 to 18:00 Output : 12:00
and 20:00 to 06:00 Output: 10:00 with +ve sign only. No -ve sign.
Thanks,
N.L.Narayana

check this .
data : p_timel like sy-uzeit,
       p_timeh like sy-uzeit,
       diff like sy-uzeit,
       di(8) type c .
       p_timel = '200000'.
       p_timeh = '060000'.
       diff = p_timeh - p_timel.
       concatenate diff+0(2) ':' diff+2(2) into di.
       write:/ di.
also check for this.
       p_timel = '060000'.
       p_timeh = '180000'.
see if this can be implemented in ur code .
or else u can try with Fm L_TO_TIME_DIFF passing startdate enddate starttime endtime with UOM as MIN
hope this helps regards,
vijay

Calculate the Difference Between two dates excluding weekends and Holidays

Hi,
We need to calculate the difference between the two dates by excluding the Local public holidays (It is global and varies across countries) and weekends should not be included in calculation for a business day in OBIEE.
We have two dates: Open date and close date when ever close date is null we are calculating age based on taking the current timestamp and need to exclude the weekends and Holidays when ever the close date is null.
Ex:
Col1 col2 Total
11/9/2010 2:46:38 PM Null 13
11/2/2010 8:06:26 PM 11/3/2010 5:37:03 PM 1
(In the Total we shouldn't include the weekends,holidays)
Please let me know how to calculate the difference between two dates by excluding the weekends and holidays.
Thanks
Edited by: user10441472 on Nov 22, 2010 3:14 PM

You already asked this question and I answered it...
Re: calculation of Business day in OBIEE

Calculate the difference between two dates times in infopath form 2013

Hi,
I have an infopath 2013 form that contains three fields:
2 date time and the 3rd contains the difference between the two in hours
how I can make the difference between the two so that the display will be like this:
Date Time1 08/21/2014 22:00
Date Time2 08/22/2014 1:00
Diff Field 3:00

Hi,
Please refer to the following article which matches your requirement exactly.
Calculate the difference between two date picker controls in InfoPath using rules and formulas - no code!
Please mark it answered, if your problem resolved.

Calculate the difference between two dates

I would like to calculate the difference between two dates in PL/SQL and return the result as a number of days expressed as an integer value.

Denes,
A fair point, I should really have posted this on the SQL forum (I'm new to the forum as well as PL/SQL) but thanks for responding anyway. It does raise a question as to how to implement this in ApEx though.
I have created the function and am calling it as shown below from the source window of a form. The source type is 'PL/SQL expression or function' and the expression in the source window of the form is:
calc_date_difference (:p26_c_payment, :p26_c_rec)
The two parameters being passed are of type date but I'm not sure how to handle the ruturned number and populate the form in ApEx with this value.
Is it possible to do it this way or am I taking completely the wrong approach?
Regards
Sandy
This is not ApEx related but SQL related:
CREATE OR REPLACE FUNCTION calc_date_difference (
p_date_1   VARCHAR2,
p_date_2   VARCHAR2
RETURN NUMBER
v_difference   NUMBER;
v_sql_err      VARCHAR2 (4000);
BEGIN
v_difference := TRUNC (TO_DATE (p_date_1)) - TRUNC
(TO_DATE (p_date_2));
RETURN v_difference;
CEPTION
WHEN OTHERS
THEN
v_sql_err := SQLERRM || CHR (10) || CHR (10) ||
SQLCODE;
ND calc_date_difference;and
SQL> SELECT calc_date_difference ('23.01.2007',
'20.01.2007') diff
2    FROM DUAL;
DIFF
3
Denes Kubicek

As to the data type of the data type of the difference between two date type of datas

Hi,
I have a question about the data type of the difference between two date type of datas.
There are two date type of datas as:
SSHIPMENTS.RECEIVEDATETIME
SSHIPMENTS.PROMISEDATETIME
I try to use the following SQL Script in Oracle SQL*Plus as:
SELECT CASE
WHEN (SSHIPMENTS.RECEIVEDATETIME - SSHIPMENTS.PROMISEDATETIME) < '000 01:00:00.000' THEN 'OnTime'
WHEN (SSHIPMENTS.RECEIVEDATETIME - SSHIPMENTS.PROMISEDATETIME) < '000 01:30:00.000' THEN '60-89 Minutes'
ELSE '3+ Hours'
END
FROM SSHIPMENTS;
The error message of "Invalid Number" for the '000 01:30:00.000' happens.
I don't know if the data type of the interval is wrong.
Many Thanks,
Cathy

SELECT CASE
WHEN (to_char(SSHIPMENTS.RECEIVEDATETIME,'hhmiss') - to_char(SSHIPMENTS.PROMISEDATETIME,'hh24miss')) < '010000' THEN 'OnTime'
WHEN (to_char(SSHIPMENTS.RECEIVEDATETIME,'hhmiss') - to_char(SSHIPMENTS.PROMISEDATETIME,'hh24miss'))< '000 01:30:00.000' THEN '60-89 Minutes'
ELSE '3+ Hours'
END
FROM SSHIPMENTS;
just try it out..

How to write a VI to measure the difference between two analog inputs (voltage)

Similar Messages

Maybe you are looking for