Recording peak load with Labview

i have an application where a cylic load is applied to an object via a load cell. I need to record the peak load of every cycle and plot it on an XY graph versus the cycle number.
However, the only trigger available to tell labview to look for a peak and add a count to the cycle number, is when the load goes over a certain threshold. The load is over that threshold for 3/4 seconds normally.
I am struggling to:
1. Add a single count i.e. if I use a case structure the condition is true for 3/4 seconds so the count is not single
2. Record the peak load - If I use a while loop, the live load cell reading freezes at the point the loop starts.
I appreciate it is probably very easy code and I'm being a bit thick - but can someone help please!!

Hi,
Attached is a sample VI that shows the two types of peak detector available side by side. For the point by point graph I have also divided by the cycle time in samples and returned only the quotient that should give the cycle number. Is this what you were after?
Regards,
James Mc
========
CLA and cRIO Fanatic
wiresmithtech.com/blog
Attachments:
Peak Detector Example.vi ‏32 KB

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Hi George,
500 users sending 4 not very heavy objects does not seem like a lot. I
would guess that you would see some brief sluggishness in the clients,
followed by normal behavior. Before you act on this, I reccomend setting
up a test to simulate this. The Forte Consulting group has done a lot of
work on this issue, and may have a lot to offer setting up such a test.
There are several ways to simulate the server going down. In reverse order
of extremity:
* Shut down the partition in econsole/escript
* Kill the process via the OS
* Pull the network plug from the server
* Shut down the subnet (or equivalent) where the server resides
* Kill the OS
* Cut the power to the server
* Something more drastic?
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clients.
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CSB
-----Original Message-----
From: Vallas, George
Sent: Tuesday, March 02, 1999 6:54 PM
To: Forte News Group
Subject: Peak Load
I am looking for a way to repopulate some simple state information (list of
proxies) to a backup copy of one of my SO's once the primary SO fails over.
I had sent a request to the news group awhile back and received some great
suggestions about writing to a file or to the DB. However, since the state
information is data that CAN be recovered by the client app (i.e. node
name,
client id, pointer or proxy through the passing of an anchored object) we
decided not to write this data to persistent storage but rather have the
client re-register themselves with the SO by sending the appropriate info
over to the SO (including the proxy back to the client). My question is
this: If the SO goes down while a large number of users are logged on
(lets
say 500) and they all re-register themselves on the backup SO at the same
time (passing 3 TextData objects and a proxy to the client) how much load
will this cause and will it be enough of a load to hang the application?
Another Question is: How does one go about forcing an SO to failover for
testing purposes?
Thanks you for your assistance!!
George Vallas
Systems Engineer
EDS Medi-Cal - Systems
3215 Prospect Park Dr.
Rancho Cordova, CA 95670
Phone: (916)636-1183
mailto:[email protected]

Hi again,
You don't need a nice operation team to look at the dependencies on production.
In fact, it would not be a good idea if you use autostart. But you can
synchronize your service objects. You can look at synchronization components
(without source code : it's for sale) and a short user sample on
http://perso.club-internet.fr/dnguyen/ (CmpSynchro is the component library and
Sequence & Synchro is the sample).
Hope this helps,
Daniel Nguyen
Freelance Forte Consultant
http://perso.club-internet.fr/dnguyen/
Peter Sham (HTHK - Assistant Manager - Software Development, IITB) a écrit:
Hi,
Thanks for your reply. It's really an interesting and intriguing. I once
have some thought on this but dropped the idea soon. The reason is ...
If I implement question 1 with events, what if the SO misses the event as
event doesn't guarantee delivery. After all, to implement such scenario,
there would be a dependency between the startup sequence of the SO. As I
don't have a nice operation team to watch the system, I dropped this idea.
My finally decision is to implement it using database synchronization.
Given the story, I would really appreciate if you can share some idea with
me on such concerns too.
Regards,
Peter Sham.
-----Original Message-----
From: Dimitar Gospodinov [SMTP:[email protected]]
Sent: Wednesday, March 03, 1999 6:14 PM
To: Peter Sham (HTHK - Assistant Manager - Software Development,
IITB)
Subject: Re: Peak Load
Hi,
I am from Sergei's group too...
For question 2 - it just listens for the RemoteAccessEvent. When the
SO is down
all registered clients will receive this event. This event is posted
only if the
SO is with session dialog duration.
According point 1, you can get a reference to all replicates by some
simple
protocol. For example posting an event that all replicates are
registered for.
Each replicate will respond to this event by posting another event
that contains
a reference to the replicate. The SynchronizationMgrSO is registered
for the
second event so it will get all events posted.
Hope it makes sense,
Regards,
Dimitar
"Peter Sham (HTHK - Assistant Manager - Software Development, IITB)"
wrote:
Hi,
I'm interested in your implementation and have some questions:
1. How do SynchronizationMgrSO gets a reference to allreplicas of
NotificationMgrSO?
2. How does a NotificationMgrSO know whenSynchronizationMgrSO has
crashed?
Best regards,
Peter Sham.
-----Original Message-----
From: Sergei Sherstyuk [SMTP:[email protected]]
Sent: Wednesday, March 03, 1999 12:19 PM
To: Vallas, George
Cc: Forte News Group
Subject: Re: Peak Load
I'm very new to Forte but it happened that we had thesimilar
problem in our labs - we had to
develop the fault tolerant NotificationManager. Actuallythe first
our approach was the same as
yours - to force clients to reregister themselves to SO
(NotificationManagerSO) after it restarted.
But then we implemented another schema. May be it is morecomplex
but IMHO more robust and scalable.
We have load balanced (!) NotificationMgrSO with 2 or 3replicas and
additional
SynchronizationMgrSo. The every call tosubscribe/unsubscribe to
NotificationMgrSO comes to
particular replica. This replica registers thissubscription and
then call SynchronizationMgrSo to
make the same changes in all other replicas.SynchronizationMgrSO
has references to every replica of
NotificationMgrSO. SynchronizationMgrSO is fault tolerant.And if it
fails and restarts all replicas
of NotificationMgrSO should reregister themselves at newinstance of
SynchronizationMgrSo - it is
the same technique that you use for clients but at the SOlevel and
hence no problems of
overheading.
Of course there are some issues with this approach but itworked.
The main advantage is that clients
don't wary about their services were restarted.
May be I don't understand well your second question but wetested
our application simply shutdowning
partitions with SO from Environment Console.
Sincerely,
Sergei Sherstyuk
"Vallas, George" wrote:
I am looking for a way to repopulate some simple state
information
(list of
proxies) to a backup copy of one of my SO's once the
primary SO
fails over.
I had sent a request to the news group awhile back and
received
some great
suggestions about writing to a file or to the DB.
However, since
the state
information is data that CAN be recovered by the client
app (i.e.
node name,
client id, pointer or proxy through the passing of an
anchored
object) we
decided not to write this data to persistent storage but
rather
have the
client re-register themselves with the SO by sending theappropriate info
over to the SO (including the proxy back to the client).
My
question is
this: If the SO goes down while a large number of users
are
logged on (lets
say 500) and they all re-register themselves on the
backup SO at
the same
time (passing 3 TextData objects and a proxy to the
client) how
much load
will this cause and will it be enough of a load to hang
the
application?
Another Question is: How does one go about forcing an SO
to
failover for
testing purposes?
Thanks you for your assistance!!
George Vallas
Systems Engineer
EDS Medi-Cal - Systems
3215 Prospect Park Dr.
Rancho Cordova, CA 95670
Phone: (916)636-1183
mailto:[email protected]
To unsubscribe, email '[email protected]' with
'unsubscribe forte-users' as the body of the message.
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Dimitar Gospodinov
Consultant
International Business Corporation
e-mail: [email protected]
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Message Edited by hemmerling on 01-11-2007 12:35 AM
Message Edited by hemmerling on 01-11-2007 12:37 AM

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