Homing motors and negative positions

Hello all,
I am using two stepper motorized stages (an x axis and y axis) from ThorLabs and am having a problem controlling them with my program after they go to their forward home position. The forwrad position is with the actuators and stages all the way in so it reads 0mm. I have a program in LabView designed to move them both but the problem seems to be that any position with the the actuators and stages extended at all is a negative position. My code uses loops to provide the input to the move absolute method but its inputting a positive number and there is no more room for it to move in a positive direction. Negating the input doesn't seem to work either, I get an error message that say something about the parameter being out of bounds.
Any suggestions would be great!

I guess I'm not 100% sure what you mean so I'll just guess. I'm using a dual channelThorLabs controller, and the motors are using theactivex methods in my code to move. Is this what you meant?
Thanks,

Similar Messages

Invoice with positive and negative rows.

Hi all,
I have a customer with mobile sales and when he invoices a customer he needs to add positive rows with the products drops off and negative rows with product he collects, so the invoice total amount is the sum all the positive rows minus the sum of all the negative rows.
So you can have an idea of what I'm talking about, imagine the milkman drops off six bottles of milk and collects two empty ones. If the empty bottles have a price, he needs to invoice six full bottles minus two empty ones.
The problem: If I create a AR invoice with negative quantities I cannot copy it to an AR Credit Note. And, if I need to cancel that AR invoice, I cannot create an AR Credit Note with negative quantities...
The customer creates about a hundred of this documents a day, so I need a direct solution.
Does anyone have an idea?
Thanks in advanced.
Best Regards,
Vitor Vieira
Edited by: Darius Heydarian on Mar 20, 2008 3:45 PM

Hello Suda,
No, just Portuguese for the time being.
But you can contact then directly to [email protected]
Marco Rangel is their Product Manager and he can provide you with information about the product.
I know that their product is already translated to French, and if not already done, the translations to English is not very dificult (the product was developed to be easy to translate).
Best Regards,
Vítor Vieira

Positive and Negative Frequency deviation Calculation

Hi ,
Iam using PXI 5600 with PXI 5620 for RF measurement.
I need to measure Positive and Negative frequency Deviation. The NI example vi "MT RFSA Demodulate FM.vi" gives peak Frequency deviation . Can any one please help me to find positive Frequency Deviation and Negative frequency deviation from it
Thanks,
Niju.
Solved!
Go to Solution.

Hi Niju,
First things first - the 5600+5620 combined is what we refer to as a PXI-5660 RF Signal Analyzer.
The PXI-5660 cannot be progammed via the NI-RFSA driver. The Modulation Toolkit FM example you reference is for the PXI-5661 and PXIe-5663 analyzers, both of which use the NI-RFSA driver.
You should use MT ni5660 Demodulate FM.vi, located under ni5660 examples.
Now on to your question...
When you perform an FM demodulation, the resultant data out of the MT Demodulat FM subVI is frequency vs. time, with the frequency (Y axis) values being relative to the specified carrier frequency. So, the data is frequency deviation (Hz) vs. time. All you need to do to get positive and negative frequency deviation is to use a LabVIEW Array Max & Min primitive from the Array functions pallette. This will give you the min and max value of the FM data which will be the peak negative and peak positive frequency deviation.
Regrds,
Andy Hinde
RF Systems Engineer
National Instruments

How can i design square signal which having a positive and negative values equal to each other and separated from each other by controlled time or distance

How can i design square signal which having a positive and negative values equal to each other and separated from each other by controlled time or distance, As it is shown in the figure below. and enter this signal in a daq.
Solved!
Go to Solution.

By the time you spend for the nice diadram you might have done the vi
Your DAQ like to have a waveform (array of values and dt ak 1/samplerate)
If you set the samplerate you know the array length , create a array of zeros, and set the values of both amplitudes ...
Since I don't want to wire others homework here are some pictures
And there are some drawbacks is room for improvement in my solution, just think of rounding errors ... and what might happen if the arrays get bigger ....
Spoiler (Highlight to read)
Greetings from Germany
Henrik
LV since v3.1
“ground” is a convenient fantasy
'˙˙˙˙uıɐƃɐ lɐıp puɐ °06 ǝuoɥd ɹnoʎ uɹnʇ ǝsɐǝld 'ʎɹɐuıƃɐɯı sı pǝlɐıp ǝʌɐɥ noʎ ɹǝqɯnu ǝɥʇ'

Positive and Negative Sign

Hello everyone,
May I know why the standard freight cost is negative sign in SD but positive sign in COPA.
Also sales and various kind of cost are showing positive sign in COPA. No negative sign in COPA?
Thank you.
Regards.

Hello,
It is also possible to transfer conditions from MM to update billing data in pooled payment in the Information Systems (IS) retail system. These are transferred according to the same rules as SD conditions. Conditions from SD are always transferred to COPA with + signs, with the exception of credit memos and returns. The reasons for this is that the signs for revenus are handled differently in the different applications of the system. For example, revenus are positive in SD, while they are negative in FI. Consequently, COPA accepts all of the values as positive, and then subtracts deductions and costs from revenues in IS.
Note that indicator transfer +/- is not used to compare the different use of +/- signs between FI or SD and COPA. If you active the indicator, only the positive and negative values for the condition in question will be balanced. This guarantees that the sum of the negative and positive condition values are displayed as a correct total value in the value field asigned to that condition.
In order to perform transfer conditions from the billing documents the same definitions must be established for the value fields in Profitability Analysis and both pricing and conditions types must be defined in SD.
Regards,
Ravi

Numeric Integration of positive and negative values in the same signal

Hello.. I need to perform an evaluation of Area Under Curve of my signal, but it contains positive and negative values. I am using the "Numeric Integration" function, but the result expressed by my VI represent: AREA OF POSITIVE VALUES - AREA OF NEGATIVE VALUES, in other words, my result represent the difference between these two areas. But I want to know the total area, the sum of positive values area and negative values area, and because both values has are "+", my final result should has "+" notation.
For example:
Area of positive values: +45.00
Area of negative values: +34.00
Total area: +79.00
How do I modify my VI to obtain the total area value?
I try to split my values in two parts:
A) only the positive and zero values
B) only the negative values
I calculated the areas of both splits and performed an sum of them, but the final result does not matches with total area (computed by another software to know the real value)
I attached an picture of my VI
Thank you
Daniel
Attachments:
Numeric Integration1.png ‏12 KB

Use an event structure for the boolean value changed. You also did not follow Lynn's advice to insert an "absolute value". It would really simplify everything.
Here's how it would look in a newer version of LabVIEW (your icons look different because you have an older version. The functions are the similar).
This is just a draft and the program needs to be improved. Use a state machine with events for read file and another for value change on the sampling rate. Place the data array in a shift so you can change the sampling rate without the need to re-read the file. Modify as needed.
Some important pointers in general:
There is NO need to constantly spin the loop every nanosecond. The only time the loop needs to spin if if one of the inputs has changed.
If you don't use an event structure, all UI loops need a wait to conserve CPU.
Never (almost never) use "switch until released". Typically you want to use "latch when released" which makes the terminal true exactly once until the value is read and it will revert to false after that. "switch until released acts like a doorbell, so if it werent for the file dialog, you would execute the case several times in a row.
You don't need to get the array size and wire N of the FOR loop if you are autoindexing. LabVIEW will spin the loop until it runs out of elements automatically.
There is an atomic operation for "negate" in the numeric palette. No need to multiply with a "-1" diagram constant.
There is an atomic operation for ">=0" in the comparison palette. No need to compare with a "0" diagram constant.
Use a stop button on the loop termination.
Everything that only needs to be done once after the file is read (e.g. you inner loop, etc. also belongs inside the case structure. Right?
In general, you would make things much easier for us if you would attach your actual live VI instead of dead images.
Message Edited by altenbach on 04-19-2008 12:22 PM
LabVIEW Champion . Do more with less code and in less time .
Attachments:
areaPositive.png ‏9 KB

Wht is Positive and Negative testing?

Hello Gurus,
                I have got a task of doing positive and negative testing for the created program but i have got no idea how to do please can anybody help me out to achieve this task.
I have created a program - ZASDF and TxCode as ZSDF.
Thks

hi,
Positive Testing :: A kind of testing who's aim is to pass the software.In positive testing we put all valid inputs.
       Positive Testing is carried with an idea of checking whether the Application works as per requirements or not. In otherwords, making sure of whether the system does what it should really is intended to do(generally this is a typical developer's attitude)
Negative Testing is trying to make sure that the application "does what it should not and does not what it should"(generally, this is a typical tester's attitude)
        negative testing is   A kind of testing who's aim to fail the software.In nagative testing we put all invalid inputs.
thanks,
raji

Different color for positive and negative chart

Hi-
I have a spreadsheet that displays data as a 3D chart - I would like to make the Positive and Negative values different colours (i.e below zero is RED - is that possible?
Thanks!
Andy

Hi Andy,
You can assign the negative values to one series and the positive values to another. Here's an example:
Column C in the Chart Data table contains the expression:
=IF(B<0, B, "")
Column D in the Chart Data table contains the expression:
=IF(B<0, "", B)
To create this chart, click on Column Label A, then Command-Click on Column Labels C and D. This sets you up to create a 2-series chart. Then Insert a 3-D Area Chart.
The 2 series are offset in the Z-axis, so some angles of view won't look so good, but you can experiment and find a view angle that works for you.
Jerry

Is there a way to separate an array into it's positive and negative elements?

I'm working with an array, and I'd like to be able to seperate this array into it's positive and negative elements. I'd like to be able to store each of these values in two other arrays (positive and negative arrays if you will). If anyone could suggest an algorithm for doing this, I'd appreciate any help I can get.

Actually, if you slightly modify the VI in the example, you can use it as a sub-VI for your application. In the front panel, right-click the VI's icon located on the top-right of your VI. Then select "Show Connector" and add the necessary connetcors to the VI (One for the input and two for the output) for the VI so it can be used as a Sub-VI. Save it with a different name and location so you don't change the original.
www.vartortech.com

Difference between a positive time and negative time management.Explain with screenshots.

Hi gurus!
I would like to know the difference between Positive time management and negative time management.
thx & regards,
raju

Hi Nagaraju,
I am adding more information..
Whether or not an employee is on positive or negative time is determined by the time management status on IT0007. Status 1 or 2 = positive time; status 9 = negative time.
In a standard system, positive time recording means the employee is required to record time (absence or attendance) for any day on which he is scheduled to work according to his generated work schedule. Negative time recording means an employee does not need to record time unless he has an exception to his normal working time; so absences are typically recorded as well as overtime or time work on days for which the employee is not scheduled to work.
Schema TM00 is used to process positive time employees for whom clock times are entered; that is, every record has a start and end time.
Schema TM04 processes both positive and negative time employees. The key distinction between TM00 and TM04 is TM04 does not require start and end times on every entry. Records with start and end times cna be processed in TM04. However, the records do not require these entries.
In TM04 you will see code using IF, ELSE, ENDIF statements during the import process to separate the import of time data for positive and negative time employees.
Positive time employees use the following data import statements in the schema:
P2011 Import IT2011 records to TIP; regardless of whether the EE has IT2011, load the work schedule to TZP. If no IT2011 record exists, TIP is empty.
P2001 Load absences
P2002 Load attendances
Negative time employees use the following data import statements:
P2000 This is the critical difference between positive and negative employees. P2000 loads the daily work schedule to the TIP table as if the employee workede; that is, if the employee is scheduled to work from 8:00 to 17:00, this record will now appear on TIP. The work schedule details are also added to TZP.
P2001 Load absences -- to pick up exceptions to planned working time
P2002 Load attendances -- again to pick up exceptions, special costing information, overtime, alternate payments, premiums or any other variation from normal schedule work.
So if you want to determine if you are using positive or negative time, check the time management status on the employees.
Regards
Siva

What is False negative and False positive

Hi Gurus,
What is False negative and False positive?
what situations they will arises and what is the impact on database/cube?
Give me some examples.

yes, one of my friend has across this question in an interview.
the interviewer has explained like this:
Occasionally, some times clean blocks are marked as dirty,this is called false negative
and dirty blocks are marked as clean status is called as false positive.
I would like to know when this situation arises and what is the impact on the database/cube.

SD condition for both positive and negative....

Hi Gurus,
I have struck with on e issue please explain the below case:
I have SD Condition types:z105, z118.z115,ziet.
Z105 assigned to AcconTING key ERF For ERF One gl account has been linked that is 404001(12) this is Freight Chg for CST value in V/06(SD)
Z118 assigned to ERF For ERF One gl account has been linked that is 404001(12) this is Freight Allow Cond.(-) value in v/06.
Z115 Assigned to JET for JET one gl has been linked that is 408011(11) this is Freight Surchage in V/06.
ZIET Assigned to JET for JET one gl has been linked that is 408011(11) this is State Entry Tax (+/-) in V/06.
The z105, z118.ziet three condition types linked to one value field VVFRO(This value field they are showing under deductions)
Z115 assigned to VVFRE(This is Revenue)
But in report I am not able to match the sum of these two GL balances with Sum of two value filds?
IN KE4I NO +_ symbol was assignd to any VALUE FIELD..
Please clear my confusion.
Thanks,
Chandu

Hi,
The following table shows an overview of how condition values are updated in CO-PA for billing documents from SD:
Billing document (normal) "With +/- sign"    "Without +/- sign"
Debit posting                         negative           positive
(such as sales deductions)
Credit posting                        positive           positive
(such as sales revenues)
Credit memo/return       "With +/- sign"    "Without +/- sign"
Debit posting                         negative           negative
(such as sales revenues)
Credit posting                        positive           negative
(such as sales deductions)
regards
Waman

Showing Postive Values as negative and negative values as negative itself

Hi Experts,
I want to bring using a formula the value in negative always how this can be done pls advise.
For example
{Field 1 - Field 2 } e.g - = 1 here the value 1 is coming as postive and sometimes the same
{Field 1 - Field 2 } e.g - = -2 here the value -2 is coming as negative
Now I want that there should be some formula that in the above scenerio the Positives are made as negative and negative values stays as negative only.
Please advise how this can be achieved.
Regards,
Venky

Hi Venky,
You can add to your formula like:
If {Field 1 - Field 2 } > 0 Then
({Field 1 - Field 2 }) * -1
Else {Field 1 - Field 2 };

Move motor and make a measurement (thorlabs motors and drivers)

Hi everybody,
I was just born in this Labview world and I´m quite lost. I´ll explain my situation:
I have three motors from thorlabs (T-cube Stepper Motor controller) in three directions (x, y and z). What I need is to move the motors from initial position until final position in small steps in order to make measurements in every stop (this is other story). So, the thing is I need to measure one line in x stopping wherever I need, then come back to the initial point, go one line down in y axis and start the line in x again (as many times as neccesary). I think a state machine is what I need for this purpose, but I have no idea.
Could anyone help me with this??
NOTE: the computer is an old xp without internet conection and there is no possibility to install labview packages as NI-DAQmx so I must use the motors nodes and properties that Thorlabs provides.
Thank you very much!!!
Solved!
Go to Solution.

Times to wait BEFORE a measurement is started is something you have to do manually since it's up to the user.
As far as how long to wait for the measurement to complete, the manual has examples of using registers and buffers to find out when the measurement is complete using a linear sweep (this is how I do it). The idea is to pre-set the buffer equal to the number of datapoints (say 100 over your IV range), instruct what to measure (current, voltage, both), and poll the registers to find out when the buffer is full (say every 100-500 ms). Let the keithley 2400 set the voltages for you over the specified range and return the data set when completed.
As far as knowing when the movement is complete, you'll have to see if there is a way to detect that with your equipment (otherwise stick with the pre-programed delay). IF these are illuminated IV measurements, you could do the following. Source ZERO volts and measure current. check periodically after the movement commands are sent. Once you measure a current, the Jsc for the cell, you have contact.
For data storage, use shift registers on the state machine itself. Clear the register when starting a scan, and insert each measurement as it is taken (2D array, or array of clusters). Another possibility is to use a separate while loop to save the data (a consumer) with the data being passed in a Queue and appended to file after each scan (this will help if you are concerned about failures resulting in lost data). After each measurement, enqueue the data into a queue handled by this consumer. (you'll need to keep track of which file to append data to).

Simple straight line motion control with brushless motor and encoder/microswitch

I want to go build a motion control system/program using labview. I have a brushless motor and a controller and a National instrument DAC (NI USB-6009). This is how my system looks like: receive an input signal 4-20mA, this should be converted to 0-5V for the controller for speed, controller should move motor till it hits micro switch. The micro switch/encoder should generate a signal (5V) back to shut the controller. I want to record the position of the motor in labview. How do I do this? How do I set the system up? Thank you in advance

Controller from anaheimautomation: MDC151-050301
Motor:BLWSG234D-36V-4000-R3
Controller and motor go together.
The input signal for the system will be 4-20mA. Using this signal I will correlate it to a specific voltage which will drive the speed of the motor. This will displace the lead screw linearly. I will have a microswitch that will be triggered by screw and will relay a signal to shut the motor. I want find a way to record the position of the shaft/leadscrew at that specific point. I want to identify a home position, halfway position and full length travel position. I will use 3 swiches or 1 switch in three positions to identify all these points.
My end result should be whwn I turn on the system or start the program It should detect whether it is at the home position, if not travel to home then respond accordigly given an input signal(4-20mA).
How will I program such on labview...finding all the right icons to record the data is such a mess for me since i'm a beginner.
Thanks

Homing motors and negative positions

Similar Messages

Maybe you are looking for