Tcp state machine trigger

Hello, I am working on some statemachine architecture, I was wondering what the best method of sending states between vis could be. Essentially I would like to send states to be read over TCP as triggers for the various parts of the statemachine in another VI. Basically it would be like the following:
VI1: Statemachine1: Idle->State A->Send Trigger (Trigger1)->Wait for trigger (Trigger2)-> State A or ->End
VI2: Statemachine2: Idle-> State B-> Wait for trigger (Trigger1) -> Send Trigger (Trigger2) -> State B or ->End
State A and State B are arbitrary, Trigger1 and Trigger2 I am hoping to be merely state cases sent via TCP.

my suggestion would be in each application have a tcp loop and a Queued message handler loop. State machine 1 goes to state A, puts a 'send trigger1' message in a queue to its tcp loop. The TCP loop reads this from teh queue then sends this message to application 2, which reads it, stick the message in a queue to the state machine 2 loop to process.
By doing this you decouple your tcp logic from your state machine logic. From my experience, it is never good to mix network communication logic in the same loop as your data processing. TCP does some weird things if you aren't getting back to the "TCP Read" function on one end as quick as you are writing on the other end. I tried this once a couple years ago in order to simplify my architecture on a relatively simple and quick program, but it actually ended up taking more time troubleshooting the TCP IP. Now I always keep them separate.
CLA, LabVIEW Versions 2010-2013

Similar Messages

State machine VS producer consumer architecture - Time Analysis

After learning various methods to program efficiently and learn how to use SM and Producer consumer. I built a program to control stepper motor in both these techniques.
Here is the RESULT. As we can see a simple state machine without any complicated producer consumer technique performs faster than the second one.
I am not sure which is still the best based on performance and optimization. Please advise which one should I keep and why.
Abhilash S Nair
Research Assistant @ Photonic Devices and Systems lab
[ LabView professional Development System - Version 11.0 - 32-bit ]
LabView Gear:
1. NI PXI-7951R & NI 5761
2. The Imaging Source USB 3.0 monochrome camera with trigger : DMK 23UM021
OPERATING SYSTEM - [ MS windows 7 Home Premium 64-bit SP-1 ]
CPU - [Intel Core i7-2600 CPU @ 3.40Ghz ]
MEMORY - [ 16.0 GB RAM ]
GPU - [ NVIDIA GeForce GT 530 ]

This is with state machine alone
Abhilash S Nair
Research Assistant @ Photonic Devices and Systems lab
[ LabView professional Development System - Version 11.0 - 32-bit ]
LabView Gear:
1. NI PXI-7951R & NI 5761
2. The Imaging Source USB 3.0 monochrome camera with trigger : DMK 23UM021
OPERATING SYSTEM - [ MS windows 7 Home Premium 64-bit SP-1 ]
CPU - [Intel Core i7-2600 CPU @ 3.40Ghz ]
MEMORY - [ 16.0 GB RAM ]
GPU - [ NVIDIA GeForce GT 530 ]
Attachments:
Control 1.ctl ‏6 KB
Control 2.ctl ‏6 KB
Motor-UNI_Directiona Dev 3-TIME_ANALYSIS-2.vi ‏54 KB

How to start and stop video acquisition in a state machine

hello,
I'm a neuroscience student and here's what I'm trying to do: 1) trigger a GigE camera (200fps), 2) start video acquisition, 3) trigger a light that will stay on for x miliseconds, 4) trigger a valve that will blow an air puff, 5) stop the tone and the valve simultaneously and 5) stop the video acquisition 1second after 4). For that, my VI is a state machine, with a state for each trigger (ex, 1 state for trigger camera, 1 state for trigger light, ect) plus a state to "stop" and a state "time to wait". Everything was working except the video acquisition - the program would trigger the camera but only acquire one frame, because it wasn't running in a while loop and this is my first question: for a video acquisition is it always necessary to have a while loop?
I assumed the answer was yes, so I built a "consumer" loop for the camera. Putting a queue in the state "trigger camera" in the producer loop, I was then able to start the video acquisition but now the problem is to stop it in the right time. I have another queue in the "stop" state in the producer loop, but it isn't able to start the "stop" state in the consumer loop, I think that may be because the consumer loop gets "stuck" in the while loop.
I hope you can help me, the VI is attached. Thanks!
Solved!
Go to Solution.
Attachments:
trigger_cam.jpg ‏345 KB
trigger_stop.jpg ‏354 KB
Conditioning MS vi 2010.zip ‏68 KB

Hi Gak,
Thanks for the suggestions. I still didn't got it to work though. I moved the stop command to inside the while loop like you said but it didn't work. The problem seems to be in the communication between the producer/consumer loops. When I run the VI in highlight, the queue message "trigger camera" leaves the producer and arrives at the consumer loop in the appropriate time, starting the "trigger camera" state of the case structure. However, the message "stop" doesn't seem to be sent by the producer loop, so the consumer doesn't receive a signal to start the "stop" state of the case structure. Can you think of anything I should change in the producer loop so that the second state (stop) is added to the queue?
About the functional global, I read about it, it seems that either that or a local variable could work, but I don't quite know how to implement it in my state machine, since the stop of the first while loop isn't activated in the "stop" state but in the "shutdown" state. It works more or less like this: after 10 loops of triggering and stopping the camera, light and valve (so after acquiring 10 movies), it goes for shutdown. Can you show me what you had in mind with the functional variable?
Attachments:
Untitled.jpg ‏286 KB

Best way to update indicators in state machine ?

What is the best method to update indicators constantly in a SM ? ...
MY INDICATORS: I want to update the cluster of OUTPUT INDICATORS for ever new update that is happening inside the FOR LOOP (see next image). How could I achieve that ?
Abhilash S Nair
Research Assistant @ Photonic Devices and Systems lab
[ LabView professional Development System - Version 11.0 - 32-bit ]
LabView Gear:
1. NI PXI-7951R & NI 5761
2. The Imaging Source USB 3.0 monochrome camera with trigger : DMK 23UM021
OPERATING SYSTEM - [ MS windows 7 Home Premium 64-bit SP-1 ]
CPU - [Intel Core i7-2600 CPU @ 3.40Ghz ]
MEMORY - [ 16.0 GB RAM ]
GPU - [ NVIDIA GeForce GT 530 ]

Since on my machine, the second screenshot is cropped, i cannot see the complete FOR loop. You do refer to the loop writing to VISA, correct?
If so:
- Is this loop timed? If so, what is the average iteration time? Note: if this is faster than about 50ms, you should not update the indicator in every iteration as the human simply cannot see changes that fast. An average user would only see some flickering and from time to time something "readable".
- Do you update the indicators elsewhere as well?
Possible solution:
- As Yamaeda suggests: Put the indicator in the FOR loop. Works well if only this loop updates these indicators.
- Local variable: As dataflow serializes access to the indicator (variable in loop, terminal outside the state case), you wont have race conditions. On the other hand bears risks if someone introduces concurrent loops using the same indicators (variables).
- Property node "value": Same as local variable, but is bound to UI thread. Therefore, it takes more time which induces performance drawbacks. On the other hand, a property node has error in/out and is better suited to be placed in well designed dataflow programming.
- Extract UI updates from the state machine and introduce a parallel running "UI Update" loop. Refer to the Producer/Consumer template for an initial start point.
hope this helps,
Norbert
CEO: What exactly is stopping us from doing this?
Expert: Geometry
Marketing Manager: Just ignore it.

Nested State machine - Loops continuously

Hello ,
I implemented a program for first time using state machines and Enum (type def).
I have 2 state machines (nested)
I am not sure if the data flow between the Main state machine and the Sub state machine is correct. The program loops continuously ( this is a MOTOR PROGRAM) and I see that the motor keeps working continuously. It is supposed to run the mentioned Number of Steps once and then stop.
Please have a look at my code and tell me where I could have gone wrong.
Thank you.
Abhilash S Nair
Research Assistant @ Photonic Devices and Systems lab
[ LabView professional Development System - Version 11.0 - 32-bit ]
LabView Gear:
1. NI PXI-7951R & NI 5761
2. The Imaging Source USB 3.0 monochrome camera with trigger : DMK 23UM021
OPERATING SYSTEM - [ MS windows 7 Home Premium 64-bit SP-1 ]
CPU - [Intel Core i7-2600 CPU @ 3.40Ghz ]
MEMORY - [ 16.0 GB RAM ]
GPU - [ NVIDIA GeForce GT 530 ]
Attachments:
Motor-UNI_Directiona Dev 1.vi ‏49 KB
Control 1.ctl ‏6 KB
Control 2.ctl ‏6 KB

Figured out ! Thank you. One of the ENUM was not defined to the correct state.
Thank you.
Abhilash S Nair
Research Assistant @ Photonic Devices and Systems lab
[ LabView professional Development System - Version 11.0 - 32-bit ]
LabView Gear:
1. NI PXI-7951R & NI 5761
2. The Imaging Source USB 3.0 monochrome camera with trigger : DMK 23UM021
OPERATING SYSTEM - [ MS windows 7 Home Premium 64-bit SP-1 ]
CPU - [Intel Core i7-2600 CPU @ 3.40Ghz ]
MEMORY - [ 16.0 GB RAM ]
GPU - [ NVIDIA GeForce GT 530 ]

How to do state machine using events .

Hi all.
i like to create a state machine using events methos .
i have 4 functions 1,2,3,4. (event based functios) (seperate sub vis)
1.i will trigger the 1 function.
then end of the first function should trigger the next function.
like state machine .
how to create this method in labview .. i tried value signaling its still not working . what i want.
Solved!
Go to Solution.

JGar wrote:
Wouldn't it make sense to have the entire state machine within one event case? When you trigger the event case the state machine then executes like a normal state machine.
DO NOT DO THAT!!!!!! Long parts of code do NOT belong inside of an event case.
The Event Structure should be in its own state and the state machine should to to that state every once in awhile to check for user events.
Alternatively, you could put just the state case structure inside of the Timeout event case. Something like this: http://www.notatamelion.com/2015/03/02/building-a-proper-labview-state-machine-design-pattern-pt-2/
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines

State machines caveat

I have been using the state machine design pattern in programs for a
while. In this technique, it is a common practice to define boolean
switches to trigger actions in the next iteration of the machine (eg.
"TurnLaserON", "Quit", "Compute", "SetAlarm1"...). Thus, the boundary
between data and processing is easily trespassed.
This sounds to me like a possible source of errors, that should be
limited by some design rule of thumb. I tend to believe that boolean
triggers in state machines should be looked at with the same precautions
as a "GOTO" control structure.
Do you have any experience or theoretical frame to enlighten these
considerations ?
oz

Hi,
I always prefer a state machine with a state buffer. This means, every state
can, potentially, call several other states. In practice, there is a shift
register with an array of strings in it. The first string is called, and
removed. Every state can modify the buffer, so:
+ states can be put before, after or between the buffer
+ states can be removed
+ states can be filtered, sorted etc.
+ buffered states can be copied
This makes programming with state machines a lot easier. You can simply make
a state TurnLaserON, and in the calling state(s) diside what the state after
TurnLaserON has to be. This makes the program a lot clearer.
Some design rules I use (mainlly because if I don't use them, there is no
way of documenting the program):
+ states may only put states before the buffer (I call them sub states)
+ buffered states cannot be removed in a state
Using these rules, I can put the entire program on paper, without any
problem.
Still, I have to transfere information between states. This 'information'
can be a shift register with a bundle, indicators on the front panel (not
visible to the end user), a GLI, buffers, ini file reference, or whatever. I
have never found any big advantage or disadvantage for eny of them, but I
prefer indicators (mixed with buffers when convenient), because they are the
fastest to use (for me), and easiest to debug (IMO).
Regards,
Wiebe.
"O. Zimmermann" wrote in message
news:[email protected]...
>
> I have been using the state machine design pattern in programs for a
> while. In this technique, it is a common practice to define boolean
> switches to trigger actions in the next iteration of the machine (eg.
> "TurnLaserON", "Quit", "Compute", "SetAlarm1"...). Thus, the boundary
> between data and processing is easily trespassed.
>
> This sounds to me like a possible source of errors, that should be
> limited by some design rule of thumb. I tend to believe that boolean
> triggers in state machines should be looked at with the same precautions
> as a "GOTO" control structure.
>
> Do you have any experience or theoretical frame to enlighten these
> considerations ?
>
>
> oz
>

Cisco ASA 5505 Reset-I Problem with TCP State Bypass

Hello,
I have a Cisco ASA 5505 that functions as my primary firewall and a Mitel 5000 controller behind it. I have two external phone users that have been connecting through the firewall with no issues for six months until about two weeks ago. I am now seeing the following log entry on the phone trying to connect to the Mitel Controller.
6
May 16 2014
14:52:52
302014
72.135.115.37
6915
192.168.20.2
6801
Teardown TCP connection 1203584 for outside:72.135.115.37/6915 to inside:192.168.20.2/6801 duration 0:00:00 bytes 0 TCP Reset-I
My phones are designed to work with the Mitel 5000 and Mitel 3300 phone controllers. The 5000 will only use port 6800 for call control, while the 3300 will use 6801 (Secured Minet), 6802 (Minet SSH), and if those fail, port 6800 (Minet Unsecured). When the phones initiate a connection, they try 6801 first. If 6801 is unavailable, the phone controller adds the RST flag to the ACK packet. When the phone sees the RST flag, it is supposed to reset and use the next port (6802). The same process happens again for port 6802, then the phone knows to try 6800. The problem is that the ASA sees the RST flag now and terminates the connection at the firewall. Therefore, the phones never see the RST flag, and continue to try the connection with port 6801.
I have tried to use the TCP State Bypass feature to correct the situation, but the log shows that the connection is still being terminated immediately by the firewall. I am a novice when it comes to configuring the ASA. Any help would be greatly appreciated, as the company that I bought the phone system from is out of troubleshooting options. I do not think that I have made any changes to the firewall around this time. I have packet captures and logs from my ASA and I have wireshark data on the inside of my network. I need to figure out how to configure the ASA so that it ignores the RST flag and sends the packet back to the source.
Any help would be greatly appreciated!

Thanks Rizwan,
Still no luck. I can't even ping the otherside (office).. I am not sure if i'm running the debug rightway. Here are my results...
homeasa(config)# ping inside 10.10.5.254............. (Office CIsco ASA5505 IP on local side. I also tried pinging the server on other side (office) whic is @10.10.5.10 and got the same result)
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.10.5.254, timeout is 2 seconds:
Success rate is 0
homeasa(config)# debug crypto isakmp 7
homeasa(config)# debug crypto ipsec 7
homeasa(config)# sho crypto isakmp 7
^
ERROR: % Invalid input detected at '^' marker.
homeasa(config)# sho crypto isakmp
There are no isakmp sas
Global IKE Statistics
Active Tunnels: 0
Previous Tunnels: 0
In Octets: 0
In Packets: 0
In Drop Packets: 0
In Notifys: 0
In P2 Exchanges: 0
In P2 Exchange Invalids: 0
In P2 Exchange Rejects: 0
In P2 Sa Delete Requests: 0
Out Octets: 0
Out Packets: 0
Out Drop Packets: 0
Out Notifys: 0
Out P2 Exchanges: 0
Out P2 Exchange Invalids: 0
Out P2 Exchange Rejects: 0
Out P2 Sa Delete Requests: 0
Initiator Tunnels: 0
Initiator Fails: 0
Responder Fails: 0
System Capacity Fails: 0
Auth Fails: 0
Decrypt Fails: 0
Hash Valid Fails: 0
No Sa Fails: 0
Global IPSec over TCP Statistics
Embryonic connections: 0
Active connections: 0
Previous connections: 0
Inbound packets: 0
Inbound dropped packets: 0
Outbound packets: 0
Outbound dropped packets: 0
RST packets: 0
Recevied ACK heart-beat packets: 0
Bad headers: 0
Bad trailers: 0
Timer failures: 0
Checksum errors: 0
Internal errors: 0
hjnavasa(config)# sh crypto ipsec sa peer 96.xxx.xxx.118
There are no ipsec sas
homeasa(config)#

Data acquisition in a state machine

I've recently learned how to implement state machines, but I have a question that I haven't been able to find an aswer to.
Question:
How do I record uninterupted data (presently i'm using the DAQ assistant to record a single channel at 10kS/s at 1kS intervals) without interfering with my state machine?
Background:
I have a time sensitive test setup (measuring pressure in a rocket chamber), and I'm using labview to both record a single pressure transducer as well as operate the valves (O2, N2, igniter, etc). I'm using a state machine Labview architecture (just learned how). Presently, the DAQ assistant sits in the "Idle" state, and timers (valves need to be turned on at specific times) and manual buttons control when the other states are activated. I have a 10ms timer controlling how often each state is run, and this is the root of my concern.
Main concerns:
I'm worried that:
1) I'm forced to change my data recording to 10ms intervals to match the 10ms timer, and
2) The 10ms timer will interrupt my data recording when it's in another state.
It's very important that the pressure data is recorded without interruption but that I have high time resolution in controlling my valves as well.
Thoughts:
1) Maybe I put the 10ms timer in the "Idle" state only, and this way the other states won't interrupt the data acqusition
2) Maybe there is a way to completely isolate the state machine for controlling the valves and the data acqusition. I'm not sure how to do this.
3) People on the forums have been talking about Queuing their data acqusition, but I'm not sure how this would benefit my situation.
Thanks to everyone for their feedback!

The data acquisition and state machine timer do not have to be equal, you should however have the same data write rate as you have data read rate, otherwise over the course of long running programs you can build up a large buffer of data to be written using a lot of memory, or lose data.
Your data acquisition should be continuous, the most common way of doing this is every time you receive data write it to a queue, then when you are in other states except your data write stage you simply build up data in the queue that is to be written when you enter the write state again.
Think of it as traffic reaching a set of lights:
The traffic represents the data acquisition, there is a constant flow of it always coming through, the state of your state machine is the lights, green is the data write state clearing the queue, red is when in any other state, letting the traffic build up behind the lights.
It is just important that the light is green long enough to let the traffic not build up too much, otherwise you have a jam.
EDIT: For the basics of how queues work, look at the Queue basics example from the example finder.

Data acquisition & state machine

Hi all,
I am working on a project that is capable of data acquisition, analyse, and record processes. I have to acquire data of temperature from 8-32 channels and that of pressure from 7 channels. After analysis, I have 48 outputs. I want to record raw data (acquired) and analysis data at the same time.
1) Is it possible to record two text files (raw data and analysis data records) at the same time?
I also want to adjust acquired sample rate but I have doubts about utilizing it in a state machine. For now, I have just used time elapsed function to acquire data once in 60 seconds.
2) How could I set sample rate of acquisition except using time elapsed function?
I also have one more doubt about timing. If I needed to acquire sample once in 60 seconds, but the analysis took more than 60 secs, what would happen?
3) How can I prevent data loss in this case?
I have not prepared a user interface yet.
4) How can I utilize it? Do I put graphs and indicaters in the same VI or is it better to prepare another vi just for user interface?
Thanks in advance
Egemen
Attachments:
Program.llb ‏433 KB

Hi Egemen
-          If we need to acquire data and analyze it at the same time we recommend the architecture producer-consumer to prevent data loss, and yes you can record two text files at the same time. Please take a look to this architecture.
-          http://www.ni.com/white-paper/3023/en
-          Basically you use the first loop to acquire data and the second one to analyze and record data (using queues).
-          https://decibel.ni.com/content/docs/DOC-2431
-          You can also find examples about this architecture at the developer zone.
Regards

How can I keep a state machine readable when using large amounts of in/outputs

Hello, I am new to Labview,
Read trough the fundamentals and the
getting started and a lot of examples.
What I want to do is use a standard
state machine from the template, and add some stages, for example
orange, apple, banana. At this point I can use numeric controls to
put in the amount of oranges, apples, bananas there are. I can even
use a led to tell the user which state of the state-machine is
active.
The thing is there will be more numeric
controls and more leds and it would be nice if the code would still
be readable when there are 20 inputs and 20 outputs.
Questions
(1) It would be nice if I could use the
typedef to select the right state AND the corresponding numeric
controls and leds out of a cluster or an array kind of structure to
keep the number of wires low. Is this possible, how can I do this?
(2) I tried to put the numeric controls
into a cluster but that way I can't put the numeric control for the
apples in the upper right corner and the numeric control for the
oranges in the lower left down corner of the front panel.
(3) An example would be really nice, I
know that I saw some examples describing this problem but there are
so many examples that after a few hours of searching I haven't found
the right one yet.
Thanks in advance for the effort.
p.s. I will not use Labview to do
calculations on fruit, I am only using this to make the question
easier to understand.

I can only start a proper answer but I might as well start with that.
When I am developing State Machines I have to think about what data is used and manipulated in each state. I then have to think about where am i going to keep and manage the data. I list all of the fields that are "touched" in each state and what values are used together and which are independent form the others. After this phase of the analysis, I usually have some data structure defined (cluser array etc).
Then I flipp from thinking about the state to thinking about the data (after all this is LabVIEW and the data-flow paradigm is critical). If I see data that is only used by the State machine and is used in many of the states, then the data structure get put in a shift-register for easy access in each state. This maybe enough of an answer for your fruity question.
When i see data that is shared or only used in a handful of states then I concider putting the data in an Action Engine. Depending on how you design your AE, you can access each of the fruit totoal by name or increment etc as required.
If your app demands many fileds that are all related (can't be broken into distinct data structures) then create a cluster that has all of your values that are used by the AE. Then create an Wrapper VI for each call of the AE but only put the associated fields on the FP of the wrapper and then bundle that value into the cluster and invoke the AE.
Ben
PS: Sorry about reverting to neBulus mode but this topic could take days to cover in detail.
Ben Rayner
I am currently active on.. MainStream Preppers
Rayner's Ridge is under construction

How to use a event structure with a state machine

First, I would like to inform you that I only work on LabView part time, and have much to learn. Anything I do learn, I usually forget until I need it again, because I only work on it part time.
Using your StopWhileLoopMOD[1].vi, I am trying to put a state machine inside the event structure.
Related link: http://forums.ni.com/t5/LabVIEW/How-to-stop-while-loop-in-Event-case/td-p/465564/page/2
Here is my application: on the front panel, the user can select any combination of 7 different tests. I have created cases to perform each step of each test in the correct order, but if the user presses stop, the tests won't stop because some of the cases have a while loop inside the event structure (like you mentioned is a bad idea). The user should be able to stop the test, reselect tests to perform, and re-start the tests.
When the start button is pressed for the event structure, I need all the cases to run in the proper order, unless stop is pressed.
In the past I have indexed an array and used that to run the state machine, but it won't stop immediately.
I have sub VIs that are built in while loops because the outputs of the product needs time to stabilize.  The state machine stops and waits up to a certain number of iterations. If it passes the test, the while loop stops and the next state starts. If it takes too long, it exits and reports an error. Maybe I need to just use the state machine and not an event structure?
Is there a good example of an event structure?
metzler CLAD
Solved!
Go to Solution.

I'm not sure exactly what you are asking, but it sounds like you want to script a bunch of tests and if the user says stop, to immediately stop the current test and abandon the others? I'm going to assume that you know how to clear the array so that it will abandon the others, so I'm guessing that you are having trouble abandoning the current test? If this is indeed the case, then the problem is that you are not able to propagate the message from the main VI FP which is the GUI to the sub vi which is the test, where the test may or may not have a GUI (FP visible) of it's own. Threading was the first thing to come to mind, but this may not be necessary using events.
You can do this by passing a refnum of the stop button to the subVI, where you can then add that wait to the event case structure.
I've attached 2 VIs, mainvi.vi which is just a loop displays the count*2 (number of seconds passed since running) that will call subvi.vi and then check to see if the stop button is pressed. mainvi.vi is by no means a state engine, it is just a simple loop for demonstration purposes. subvi.vi just waits 2 seconds and leaves, it is a better structured state engine with an init state to start a poll case to wait for events and an exit state to clean up. You can modify this any way you wish to get it to do what you want. You will note that even if subvi.vi is being executed, it will terminate immediately when the stop button is pressed.
Hope this helps.
A
Attachments:
mainvi.vi ‏17 KB
subvi.vi ‏33 KB

How to use elapsed time function with state machine in Lab VIEW

Hello
I've been trying to use state machine with elapsed time function in order to sequentially start and stop my code. The arrangement is to start the code for 1 minute then stop for 5 minutes. I've attached the code, the problem is when I place the elapsed time function out of the while loop it doesn't work, on the other hand when I place it inside the loop it does work but it doesn't give the true signal to move to the next state.
Could you please have a look to my code and help me to solve this issue.
Regards
Rajab
Solved!
Go to Solution.
Attachments:
daq assistance thermocouple(sate machine raj).vi ‏436 KB

Rajab84 wrote:
Thanks apok for your help
even with pressing start it keeps running on wait case
could you please explain the code for me, the use of Boolean crossing, increment , and equal functions
Best Regards
Rajab
OK..I modded the example to stop after 2 cycles. Also recommend taking the free online LabVIEW tutorials.
run vi. case statement goes to "initialize", shift registers are initialized to their constants. goto "wait"
"start"= false, stay in current state. If true, transition to "1 min" case
reset elapsed timer with True from shift register(counter starts at zero)."time has elapsed"=false, stay in current state(1 min). If true, goto "5min" case
reset elapsed timer with True from shift register of previous case(counter starts at zero)."time has elapsed"=false, stay in current state(5 min). If true, goto "1min" case. Also, bool crossing is looking for "true-false" from "5 min" compare function to add cycle count.
Once cycle count reaches 2, stop while loop....
Attachments:
Untitled%202[1].vi ‏42 KB

Relay Testing with State Machine

Hi,
Yesterday I very kindly had some help from "crossrulz" in setting out the following procedure. Today, the National Instruments representative called and said I should implement my programme as a "State Machine", which I have attempted in the programme attached. I was wondering how I might now implement the procedures 3 to 5 in this State Machine format as it seemed very complecated in the brief time we had.
What I am trying to do is test relays, using an automated test procedure.
The procedure takes the following steps:
1. A NI9472 DO card and transistor drive turns the relay on/off via energising the coil (needs the time period to be variable).
2. Counts how may cycles the relay contacts have operated, this will easily be in excess of 100,000 cycles.
3. Every 100 cycles (again variable), the contacts are held closed, the load circuit (the current the relay is switching, which will be 15A at 30V) is disconnected, via another relay and a measurement is taken via a separate four wire method. This consists of a 6V supply being placed across the contacts (switched in again via a relay) with a 1A current flowing through the contacts, the voltage drop across the contacts is then inputted into the NI AI NI9219 card (this is in the region of 10’s of mA) and is directly proportional to the contact resistance, which is what I want to measure.
4. The measurement is taken and stored and the measurement circuit disengaged, the load circuit re-engaged, and another 100 cycles is counted before the process goes back to stage 3.
5. This process goes on until the relay fails and hopefully a large set of contact resistance data is gathered.
I have no real experience with NI Labview.
I have looked at the basic academic tutorials and have come up with the following programme for stage 1, however I can't get the DAQ Assistant to output every cycle
Would this be a very difficult programme to implement for the novice? The academic tutorials seem straight forward but when I try to do someting it seems very difficult.
Hoping someone may be able to help, thanks
Andy
Solved!
Go to Solution.
Attachments:
Relay Test State Machine.vi ‏207 KB
Relay Test State Machine.vi ‏207 KB

Hi James,
I've tried to implement some logic as suggested. I can now get the 1A coil to engauge after the nth cycle and I think it's taking a measurement, but can't seem to get the 15 A coil to disengauge at the same moment, which is crucial else the measurement will be across 16 A rather than just the 1 A. Any ideas? I just want to get it working so we can get started with testing.
I'm going to get my supervisor to book me on a course at Newbury for future projects, it's very difficult to pick up of your own back.
Kind regards,
Andy
(Helps if I attach it)
Attachments:
Relay Test State Machine.vi ‏209 KB

How do you create array of enums for transitions in a state machine?

Hello,
I am trying to build a state machine, but, I am struggling with understanding the methods for determining which state to transition to next. In other words, I have several states, but, I don't want to go in any particular sequence. If I have states numbered 1 through 10, I want to be able to go 1-4-2-5-6-2-6-1-10 etc. in no particular order. I want the transition to the next state (and actions) to be determined by the streaming data, which can be random and require access to any of my 10 states at any time and in any sequence.
I saw this picture on the "Application Design Patterns: State Machines" white paper, but, it leaves out some important details. How does one create the structure in BLUE shown in 3C? When I try to create this array of enums, all of them are the same. I am not able to make a list of different enum values. In other words, when I type in "2", then, all the values in the array display as "2."
There is a nice, simple video example of a state machine for dispensing soda for $0.15, however, this state machine moves in a single sequence, from 5 cents, to 10 cents to dispense; it does NOT illustrate how to select a state "out of order." I need to understand how a state machine can move from "5 cents" state to dispense directly, with the addition of 10 cents to the "5 cents" state.
Can anyone suggest a really good tutorial on how to make the selector work in a state machine? I have been reading some of the available material on ni.com, but, I can't find a good detailed explanation of how to do it. I remain confused.
Or, can you just explain how they created the BLUE array in the attached picture? Maybe I can figure it out from there.
Thanks,
Dave
Solved!
Go to Solution.
Attachments:
next state.jpg ‏75 KB

Hi Kathryn,
Yes, this is EXACTLY what I want to accomplish...
So it would basically run:
State 1
Read input
Determine next state (say 3)
State 3
Read input
Determine next state
State
Read input
Determine next state
And so on...
But, I am quite new to programming Labview state machines, and can't figure out how to even start when the sequence of states is random instead of fixed!!! I can do 1,2,3,4, like the vending machine VI example, but, not 1,3,2,2,2,5,2,1 etc. based on external input. Is there some simple example case I can study? I can't believe I am inventing this for the first time.
"select the state to run"
But, HOW do I do this??????? This is exactly the question I am asking...how is this done? Please see the attached 3-state system....how do I hook this up???? I am totally lost here...can you help me understand how to wire this thing?? In this simpe RED/GREEN/BLUE case, my input is just the number a user would input on the front panel.... Apparently, there are two files necessary... a vi and .ctl??? What is .ctl?
Thanks,
Dave
Attachments:
forum nov 12 red green blue.vi ‏7 KB
forum nov 12 red green blue.ctl ‏5 KB

Tcp state machine trigger

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