Aviod frequency time-out in DAQmx

I'm trying to measure the frequency of a square-wave signal from a turbine flowmeter. The flowmeter is installed in a complex system of valves, pumps, and other sensors. I have created a main VI in LV 7 which controlls this system as well as acquires data from all the sensors (mostly attached to NI-DAQmx hardware). This Vi is basically a large while loop that operates continuously until the user terminates it. The flowmeter pulse is to be measured by a single counter on a 6061E board configured by NI-DAQmx single low frequency tasks.
I have configured the task in MAX with a hi limit of 5kHz and a low limit of whatever the default is for the 10kHz time base (I think around 0.02Hz) and connected the signal to PFI4 (for counter 1) a
s instructed. My flowmeter's frequency varies from 0 to 3kHz. Since my system's flow rate is zero upon start-up of my main VI, the frequency measurement task times out, producing an error message, shutting down the VI.
Is there any way to measure my flowmeter's signal without these time-out troubles? I can't seem to find any period or frequency measurement examples that allow the signal to go to zero without creating some sort of error.
Thanks,
Tom

You have two options. The first is to wire a -1 into the timeout input of the Read VI (see attached picture). This is equivalent to an infinite timeout and will cause the driver to poll the number of samples available for reading until the requested amount of data has been transferred. The driver does yield inside of this polling loop, but it may still utilize more CPU than desired for your application.
If CPU utilization becomes an issue, you can query the Available Samples Per Channel attribute in the Read Property node (see attached picture) in your while loop instead of directly calling the Read VI. Once the available samples has reached the desired threshold, you can call the Read VI without having to worry about timeouts or blocking waiting for da
ta. This will also allow you the opportunity to introduce a sleep time in your loop to reduce CPU utilization.
Attachments:
Read.JPG ‏8 KB

Similar Messages

Change pulse width in a continuous generation using an array of High/Low Times using NI-DAQmx

Hi,
I'm using a PCI 6259 (M-Series) Multifunction DAQ, and I want to use a counter to output a pulse train with changing low times. I want to use this output signal as an update clock, where values of Digital Output Channel, and the Analog Output channels updates to new values sequentially in the order specified in their repective 1D arrays in the front panel. I want the updates to happen at every rising edge of the clock pulse. The times when I want this update to happen are also user-specified by an 1D array of times in the front panel. So I'm trying to configure one couter to output this changing width pulse train.
I'm new to Labview/Ni DAQ. I'm using NI DAQmx, so far its been really nice and readable, and easy to understand. Even though I have never used NI-DAQ, I can clearly see that NI DAQmx is certainly much more programming friendly than NI-DAQ. I looked at the VI's available in the example, and also through many simlar posts in these Forums, and some web documents for my problem. Most of the solutions have focussed on changing times on the fly while the application is running. I want to specify the different times before a "DAQmx Start Task" is called. I'm wondering wether this is possible.
I was hoping I could store the pulse width values in a buffer, and the counter could keep outputing pulses with different widths in one continuous operation. The M-Series help file says that it is possible to do that "seamlessly", but I dont see yet how I can use the NI DAQmx to do that. Attatched is the part of the Help file where it says that.
Any help will be greatly appreciated.
Attachments:
Counter_Change_Frequency_Help.pdf ‏21 KB

Hi Kevin,
Thanks for your message. Well, I would like to point you to the 'DAQmx Timing' vi, which has an instance for change detection applications with digital input. I'm new to LAbview, but I'm wondering wether you can use that for your applications. Yes, I have seen the Viewpoint boards and their programs.. I have actually also looked into their Vi you are talking about, Kevin, for ideas to use with my board, but the core of the program is in C, which is something I would use as a last option, specially since I bought Labview to make life easier.
To get back to the subject of my post, their is a vi 'DAQmx Write", and one of its instance is 'Write Counter Single Channe SINGLE Sample', and there is no 'Multiple Sample" option available for writing counters, as is for the Digital Ports and Analog Outs. That seems to be a bit surprising. To refer the following example
http://zone.ni.com/devzone/conceptd.nsf/webmain/90DFE241E571056C86256FA4004ABB63
(pulse width modulation with NI-DAQmx)
If one can change values of pulse widths on the fly, I would assume thats it should also be possible to pre-define a sequence of pulse width values in a buffer from which the counter 'banks' can access the next pulse width from. ('Banks' are the 2 load register pairs for the counters and is described in the part of the M-series help file attatched in my earlier post).
Hopefully somebody from NI can address our problem. And yes Kevin, currently I have 2 options,... 1. to create a digital waveform before hand, which will use a large buffer ( I want an experiment to run for 1s, with 0.1us timebase, or
2. To use the example in the above web document and modify it a bit. Here frequency is changed on the fly, and a while loop checks if the frequency is changed in the at regular intervals. I could instead use a for loop to keep changing the frequency values, but I tend to think that the speed will be limited by software. I'm not sure .. I haven't tries that out yet.
Hopefully someone can send me a nice elegant solution.
Thanks.
Shomu

Resource busy time out oracle message - Concurrency and Locks

I have a requirement to generate gapless invoice and receipt number in our application. so i have currently used the below approach.
a. created table with a column to hold the invoice and receipt number sequence value.
b. whenever transaction gets succeed. i will lock the table which holds the invoice number and receipt number inorder to avoid the sequential number slipages.
Issue
1. since the application belongs to online payment through portal by customers, when concurrent users trying to pay and while generating receipt number's, i am facing with "resource busy time out" message frequently. Here i noticed when user1 locks the table to access the receipt number value and session is not committed or rollback and another session user2 trying to access the same resource, in this scenario i am facing this error.
Frequency of encountering this error is low, but customer was telling us this error is show stopper and affects normal business.
Is there any alternative solution or method can be applied to overcome this problem?
Current SQL used in application
cursor <cursor name> is.
select <column_name>
into <variable>
from <table name>
for update of wait 5
update <table name> set <column name> = value + 1
where current of <cursor name>

1e0ea4a1-1610-4dec-a44c-4ee1f46ba1a4 wrote:
I have a requirement to generate gapless invoice and receipt number in our application. so i have currently used the below approach.
Engage the business and inquire WHY this "requirement" exists. I have personally never seen an audit requirement wherein invoices MUST be devoid of gaps (that's not to say they do not exist, just that I've never seen one
They certainly must be unique, but that's what a sequence will do for you. If the business absolutely needs gapless information, then they will have to be willing to pay the price which is going to be longer transaction times (as requests queue in a busy system to get this sought after gapless resource). Your job is to explain this to them ... nothing comes without a cost.
The only thing you can really do (assuming you engage the business and the requirement doesn't change) is ensure the transactions are designed in such a manner that
1) they complete as fast as possible AND that the locking is done at the latest possible stage of the transaction
2) there is no user interaction (you cannot allow the users a "review" screen of any sort ... because users get silly sometimes and go for a coffee while reviewing things)
Cheers,

No Ranging Response received - T3 time-out

Hi everyone, Our internet connection often drops, sometimes the modem reboots himself sometimes we are disconnected only for a few seconds.It happens 2 to 3 times per hour (and its getting worse this days, maybe because of the heat ?) We already had this problem last summer and a technician came and changed something outside, it was not reall better after that but we had other stuff to deal with. Before contacting the support I'd like to know if tehre is something obviously wrong wth the numbers below. Here are the logs and the connection infos. No Ranging Response received - T3 time-out;CM-MAC=b8:9b:c9:74:d5:b0;CMTS-MAC=00:13:5f:04:1c:9f;CM-QOS=1.1;CM-VER=3.0; 2015/06/28 16:09:24 critical
MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=b8:9b:c9:74:d5:b0;CMTS-MAC=00:13:5f:04:1c:9f;CM-QOS=1.1;CM-VER=3.0; 2015/06/28 16:06:16 warning
No Ranging Response received - T3 time-out;CM-MAC=b8:9b:c9:74:d5:b0;CMTS-MAC=00:13:5f:04:1c:9f;CM-QOS=1.1;CM-VER=3.0; 2015/06/28 16:06:01 critical
Unicast Ranging Received Abort Response - initializing MAC;CM-MAC=b8:9b:c9:74:d5:b0;CMTS-MAC=00:13:5f:04:1c:9f;CM-QOS=1.1;CM-VER=3.0; 2015/06/28 16:05:36 critical
No Ranging Response received - T3 time-out;CM-MAC=b8:9b:c9:74:d5:b0;CMTS-MAC=00:13:5f:04:1c:9f;CM-QOS=1.1;CM-VER=3.0; 2015/06/28 16:05:26 critical
Unicast Ranging Received Abort Response - initializing MAC;CM-MAC=b8:9b:c9:74:d5:b0;CMTS-MAC=00:13:5f:04:1c:9f;CM-QOS=1.1;CM-VER=3.0; 2015/06/28 16:05:26 critical
Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=b8:9b:c9:74:d5:b0;CMTS-MAC=00:13:5f:04:1c:9f;CM-QOS=1.1;CM-VER=3.0; 2015/06/28 16:05:16 critical
Ranging Request Retries exhausted;CM-MAC=b8:9b:c9:74:d5:b0;CMTS-MAC=00:13:5f:04:1c:9f;CM-QOS=1.1;CM-VER=3.0; 2015/06/28 16:05:16 critical
No Ranging Response received - T3 time-out;CM-MAC=b8:9b:c9:74:d5:b0;CMTS-MAC=00:13:5f:04:1c:9f;CM-QOS=1.1;CM-VER=3.0;Downstream Channel Bonding Value
Index 1 2 3 4
Lock Status Locked Locked Locked Locked
Frequency 645.002 MHz 639.000 MHz 650.999 MHz 657.000 MHz
SNR 37.936 dB 37.936 dB 37.936 dB 38.605 dB
Power 1.300 dBmV 1.842 dBmV 1.267 dBmV 1.751 dBmV
Modulation 256 QAM 256 QAM 256 QAM 256 QAMUpstream Channel Bonding Value
Index 1 2 3 4
Lock Status Locked Locked Locked Locked
Frequency 23.000 MHz 36.100 MHz 29.600 MHz 14.400 MHz
Symbol Rate 5120 KSym/sec 5120 KSym/sec 5120 KSym/sec 5120 KSym/sec
Power Level 46.5000 dBmV 47.0000 dBmV 46.5000 dBmV 45.5000 dBmV
Modulation 64QAM 64QAM 64QAM 64QAM
Channel ID 3 1 2 4Thanks for your help, regards

The stats as read at the modem level at that moment in time were o/k but there are three additional signal stats which can't be read by the modem. They can only be read from their end by them polling the CMTS (Cable Modem Termination System) at the local headend facility.
They are the 'Upstream Receive Power Level', the 'uSNR' (upstream Signal To Noise Ratio), and the "ICFR" (In Channel Frequency Response). These are as equally important in diagnosing connectivity issues as are the modem's stats.
You can call in and ask what these figures are. The Upstream Receive Power Level should fall within the range of -2dB to +2dB with 0dB being in the middle and perfect.
The Upstream SNR should be least 31dB, and the higher it is the better.
The ICFR should be no higher than 2 dB.
You could have an intermittent noise ingress issue in only the upstream channel(s) / return path only somewhere.
They will be able to see whether or not everything is in the green zone and also see a history plot for the modem.

User event or event structure time-out

Hi,
I have two VIs one is a producer, one consumer.
The consumer VI is called programatically (i.e. not wired) when the producer VI is run
Both have user interfaces using an event structure.
I have a control on the producer that i wish to use to trigger an event in/pass a value to the consumer VI. I have implemented this in two ways, but am not sure which is the 'preffered solution'.
Solution 1:
Detect control activation in the producer VI using event structure, load new value in to a global variable.
Use the time out event case in the consumer VI to load the value from the global variable.
Solution 2:
Set up a user event in the producer VI, load the Event Registration Refnum in to a global variable, use the event structure to create a new event when the control value is changed by the user.
Use Event Registration Refnum global variable in the consumer VI to trigger the event structure (loaded once, when the VI is first loaded).
Solution two means the time-out event case does not need to be active, meaning the consumer VI will be doing nothing except waiting for either the user event, or direct user interaction. It will also not have the potential time delay of up to 1 x the time-out value of the event structure. It does require a sequenced start of each VI for the Event Registration Refnum to be loaded in to the global variable before the global variable is read by the consumer VI.
My end application will be utilising a number of consumer VIs and will require user interaction information from the producer to be passed to them. Which proposed structure would be the generally accepted better practice?
...or if i've missed the best solution, where should i be looking?
Thanks,
Blue
(xp, LV 8.6)

Example of Queue based function Globals.To store the events and data.
http://forums.ni.com/ni/board/message?board.id=170&message.id=240328#M240328
Balaji PK (CLA)
Ever tried. Ever failed. No matter. Try again. Fail again. Fail better
Don't forget Kudos for Good Answers, and Mark a solution if your problem is solved.
Attachments:
AI Queue.vi ‏30 KB
DAQmx AI.vi ‏59 KB

Time out expiring issue in a Vi

Error 1073807339has occured at a VISA READ function in a Vi . Error message says "Time out expired before operation" . How can we resolve this issue - THANKS

Under Instruments I/O/VISA/VISA advanced palette you will find VISA Set Timeout (a property node with a small clock upon it): you can use it to establish a timeout large enough for your instrument to respond.
A problem can arise if your instrument is fast to respond to some messages and slow for others; in that case you must decide what to do:
- either set a large time out for all messages, but you can catch a large waiting time when you don't expect this
- or changing the time out limit from time to time, which NI says that can some way reduce the performance of your application (it depends on the volume of traffic and the frequence of this setting changing).
Roberto
Proud to use LW/CVI from 3.1 on.
My contributions to the Developer Zone Community
If I have helped you, why not giving me a kudos?

MODBUS - 6101 Time Out Error

Hi,
I have a Honeywell UDA2182 controller and am trying to read 3 data channels from it using Labview 2010 SP1 (running on XP with the VISA and MODBUS libraries installed). The PC is connected to the controller via a RS485 - USB converter.
I keep getting Error 6101 - time out error and can't resolve the problem.
The channels are from registers lines 0-3 for inputs 1 and 2 and 37-38 for input 3. If I read only inputs 1 and 2 then I don't get this error. If I read all 3 (involving reading registers 0-38) then the error occurs. It seems like it can't deal with so much data. Is there a way of reading 0-4 followed by 37-38 or only registers 0-4 and 37-38? I tried to do this using a flat sequence structure but it dosen't work, the software runs really slowly and does not sample at the correct frequency.
This reading the channels extra channels that i'm currently reading might not solve my problem and hence I'd obviously be open to suggestions on how to remove this error. I have had a read up on this error but haven't managed to solve it.
I have attached the sequenced and origional .vi's i have made.
Attachments:
Hydro Stacked.vi ‏104 KB
HydroORIG.vi ‏100 KB

Carlr,
Your modified code doesn't work because you've opened to references to the same VISA resource. See the attached snippet for an example of reading two different things from the same instrument.
Attachments:
MODBUS Read.png ‏53 KB

SSO Partner Application and Session Time out

Hi ,
We have an application on forums.oracle.com which is implementing the Authentication scheme as SSO, that is working well, now we want to implement Session Time out if the user is idle for some time and ask him to login again after the session fails, I have tried to implement this feature as given by Scott in the thread session timeout , well the problem is since we dont have a login page here how do we set the cookies owa_cookie.send(
name => 'HTMLDB_IDLE_SESSION',
value => to_char(sysdate+(20/1440),'DD-MON-YYYY HH24:MI:SS'),
expires => null,
path => '/',
domain => null
and where is the current point to implement it.
Any help on this is greatly welcome.
Thanks in Advance.

Naveen,
I don't remember how the solution works. But if you don't have a login page you can usually put code in the post-authentication process of your authentication scheme to do whatever the login page process would have done.
Scott

CRM WEB UI - Time out Pop-up

Dear All,
We have a business requirement to monitor and optimize the CRM WEB UI timeout and other related issues.
I would like to have time-out pop-up for the call center agents and hence they could better manage the sessions .
This will avoid loosing the valuable customer data for the session and so on.
We are now working on the following threads with CRM Technical folks.
Please share your experience or the detailed steps if you had implemented already.
SAP note 1877120 - CRM-IC: session timeout issue with CRM 7 EHP1 and higher
Also , have a look http://scn.sap.com/community/crm/webclient-ui-framework/blog/2012/05/17/session-time-out-warning-message-on-ui
2092893 - Session Time Out Notification
Regards
Venkat

Hello Venkat,
For business roles of type IC Webclient, you have to implement SAP Note 1877120. Don't forget to update your view layout in your custom enhancement if you have enhanced CRMCMP_IC_FRAME/HiddenView.
After implementation of 1887120, also implement 1977631 and 1955366.
Best Regards,
Sigrid

RCA Connection Pool idle Time-Out takes no effect !

My question description goes here.
According to JCA specification, I developed my 'ManagedConnectionImpl' class from the interface 'ManagedConnection'. I realize the 'destroy()' function to send out logout request to the EIS.
Then I deployed the connector in Sun Java System Application Server, I noticed there are two parameters in Connection Pool part, they are:
1. Idle Timeout. It said it's the maximum time that a connection can remain idle in the pool. I assume the connection will be removed after the specific time expired and before it's removed it will call the recallable function, 'destroy()', in my concrete class, 'ManagedConnectionImpl'.
2. Pool Resize Quantity. it said it's number of connections to be removed when pool idle time expired.
I am weird about it. I think EIS had itself session control strategy, if the specific session time-out expired, it will invalidate this session. So I think we will set 'Idle Timeout' in application server to be shorter than the EIS session time-out. If the 'Idle Timeout' in application server expired, it should remove all connections inside otherwise maybe the connection with invalid session will exist! (the background knowledge is our system will return back soap fault when it meets invalid session, so the invalid connections will not be removed by switching on your configuration item, 'On Any Failure')
So I set "inital and minimum pool size" to 8, "maximum pool size" to 32 and "Pool Resize Quantity" to 32. (I expect AS to remove all when pool idle time expired)
After deploying, I send out requests at the first round and wait for the time expired but I can't see the desired logout requests from pool automatically even one. Firstly I guess if my recallable function definition is wrong but when I shut down the Application Server, the desired logout requests are sent out from pool automatically. So I think my recallable function definition is workable.
What's your comments on it?
P.S.
I am using Sun Java System Application Server 8.1.
Thanks in advance!
BRs
/Leo

I have had following test to ensure I sent out notification to listener.
[#|2005-08-23T16:14:25.061+0800|INFO|sun-appserver-pe8.1_01|javax.enterprise.system.stream.out|_ThreadID=12;|
It's in managed env!|#]
[#|2005-08-23T16:14:25.062+0800|INFO|sun-appserver-pe8.1_01|javax.enterprise.system.stream.out|_ThreadID=12;|
enter matchManagedConnections() !|#]
[#|2005-08-23T16:14:25.062+0800|INFO|sun-appserver-pe8.1_01|javax.enterprise.system.stream.out|_ThreadID=12;|
try to find a matching and existing one, reuse it!|#]
[#|2005-08-23T16:14:25.062+0800|INFO|sun-appserver-pe8.1_01|javax.enterprise.system.stream.out|_ThreadID=12;|
Found a matching and existing one, reuse it!|#]
[#|2005-08-23T16:14:25.495+0800|INFO|sun-appserver-pe8.1_01|javax.enterprise.system.stream.out|_ThreadID=12;|
tearDown() is called, the application-level connection is released!|#]
[#|2005-08-23T16:14:25.496+0800|INFO|sun-appserver-pe8.1_01|javax.enterprise.system.stream.out|_ThreadID=12;|
enter calling close() of managed connection.|#]
[#|2005-08-23T16:14:25.496+0800|INFO|sun-appserver-pe8.1_01|javax.enterprise.system.stream.out|_ThreadID=12;|
Start calling close() of managed connection.|#]
[#|2005-08-23T16:14:25.496+0800|INFO|sun-appserver-pe8.1_01|javax.enterprise.system.stream.out|_ThreadID=12;|
start to notify the listener the completeness of connection.|#]
[#|2005-08-23T16:14:25.496+0800|INFO|sun-appserver-pe8.1_01|javax.enterprise.system.stream.out|_ThreadID=12;|
notify the listener the completeness of connection successfully.|#]
Whether it's related with the initial and minimum number parameter? Although I found it will not be created during AS start-up and will be created at the first request.
Whether it shall be kept to meet the minimum requirement? I have failed to set it to 0.

Getting time out error when running the assigned verification in DRM 9.3.2.

Hi,
I have installed DRM 9.3.2.0.0 in my system (windows 7), when i am trying to run assigned verifications i am getting the time out error within a minute.
As suggested by oracle,I have added DWORD with value 480000 under Master Data Management in Registry editor. But still getting the error.
Please suggest a solution for this issue.
regards,
sathiya

Please suggest me the solution.
regards,
sathiya

Session time out when trying to redeem card!?

hi, I have tried to redeem my card 5 times now, and itunes keeps saying "session time out your sessions has timed out please try this operation from beginning" I am dualbooting windows xp and windows 7, I have used both OS's and still the same thing. when I try to redeem it on my ipod touch it tells me I have the wrong code. I do not have a mac availble im on vecation and only brought the PC laptop.
if it matters im using the itunes canadian store.

This worked for me:
Establish in her router a WEP 128 bit data encryption password. (Post back if you need help on this). Apparently macs have slightly different Airport drivers and work better with WEP 128 bit than with WPA although this doesn't explain why my friend's MB had your mum-in-law's problem but could connect to my WPA protected network - go figure! Anyway, try a different password encryption and see if that works.
As for not sending mail, check with your Mail Server what the SMTP setting should be.
Joe

Session time out app store

I keep getting session time out whenever I try to purchase apps on iPhone 5. It keeps asking me to verify my credit card security number and then when I click DONE, it tells me session time out. Anyone can help?

Having problem with internet connectivity on WIFI - anything that depends on DNS for data whether it is a web browser or an app while using WIFI. I call this problem "WIFI Lockout".
This happens on iphone 4, ipad 2 and ipad 3 that has been updated to iOS 6.
I am not talking about the issue of the missing apple page (day 1) or the inability to turn on/configure WIFI after updating to iOS 6.
This is what i have discovered so far.
You could be in the middle of surfing or using any app that makes data calls based on DNS (when you type google.com that is translated in the background so your device knows where to go - summary only) and suddenly you can go no where or do nothing!
Sometimes conectivity goes trouble free for long periods, other times it is repetitive "WIFI Lockout".
Yea sure, you can restart the WIFI connection, but WHO wants to CONTINUALLY do that?
Interestingly enought the device is still successfully connected to the internet via WIFI, but DNS request fail to pass successfully from the iOS 6 device.
Apple (or any curious iOS 6 user that wants to see my point), when this happens "WIFI Lockout" open up a browser before you reset the WIFI connection and type type 74.125.227.144 (google) and then “go” (I tried both safari and chrome). A google search page will come up and you will be able to execute a search (of course any link you click on will not work as it is dependant on DNS resolution).
The above IP connection to google proves NON DNS traffic works, so the issue is not the WIFI connection to the access point that is the problem. It is not an access point configuration/firmware or security protocol issue either because data does pass when the above steps are followed.
I KNOW THIS IS NOT ALL OF THE PROBLEMS WITH iOS 6, BUT THIS IS A HUGE PROBLEM NOT BEING ABLE TO SURF OR GET DATA THE iOS 6 DEVICE IS REQUESTING WHILE ON WIFI.

Session time out

Hi,
Is there any way to set ovm manager gui session time out.
as of now, if there is no action in gui for 2 mins,
session gets timed out.
Importing a template takes lot of time and session is
getting timed out just after 2 mins.
I have another question. Even if session times out,
does importing template continue?
Thanks
Ram

887506 wrote:
Is there any way to set ovm manager gui session time out.There is a way to increase the WebLogic timeout, but I'm not 100% sure on the process. Best thing to do is open an SR with Oracle Support so they can provide the exact steps.
I have another question. Even if session times out,
does importing template continue?Yes, this all happens on the Server/Manager side and doesn't require you to remain logged into the UI while the job runs.

Session time out in EP & webdynpro

Hi can any body tell me how to control webdynpro session & portal session?
I have created a webdynpro application & integrated in EP. I want to control the session time out for my application because if i run my application in Ep & the session time is out, i need to refresh my dynpro application.
I want to control this session time out.
Thanks,
Siva

Hi siva..
Chk this link..
Tabstrip: navigate with buttons instead of tabs
Regards,
GS

Aviod frequency time-out in DAQmx

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