Shared Variables

[regisphilbin]

I'm very excited about this "new" method of using Shared variables to pass data around. It'll change how we use RT-FIFO's and how we configure DSC "items" while making the data easier to get to (or at least it looks that way). I think i heard that it will also be usable as a triggerable event as well.

I asked these question at the 3pm CT web event on "shared variables" today:

1) How does it compare to datasockets? Will it replace Datasockets?

A) datasockets is built on this new "shared variable engine". There are people out there relying on datasockets so no, DS technology will not be replaced. DS Vi's will still be included and supported....

I guess my follow up question would be: Is this just another name for "LOGOS"?

2) What are the performance boundaries?

A) 3 mb/sec Max transfer rate was a number that was mentioned.

3) Is there a max # of points?

A) there was no problems when tested with 10,000 items.

For those who've used the Lv8 or beta, any thoughts on this? This almost sounds too good to be true.....

Regis

[REM1]

I'm very excited about this "new" method of using Shared variables to pass data around. It'll change how we use RT-FIFO's and how we configure DSC "items" while making the data easier to get to (or at least it looks that way). I think i heard that it will also be usable as a triggerable event as well.

I asked these question at the 3pm CT web event on "shared variables" today:

1) How does it compare to datasockets? Will it replace Datasockets?

A) datasockets is built on this new "shared variable engine". There are people out there relying on datasockets so no, DS technology will not be replaced. DS Vi's will still be included and supported....

I guess my follow up question would be: Is this just another name for "LOGOS"?

2) What are the performance boundaries?

A) 3 mb/sec Max transfer rate was a number that was mentioned.

3) Is there a max # of points?

A) there was no problems when tested with 10,000 items.

For those who've used the Lv8 or beta, any thoughts on this? This almost sounds too good to be true.....

Regis

To begin with I would recommend watching the LabVIEW 8 DSC tutorial - it is NI marketing and discusses the DSC Module but it provides some additional information about the shared variable that you might find useful.

To answer some of your questions more specifically:

1-ish: The shared variable engine acts as a host, or publisher, of networked shared variable data - and hosts additional services which can be applied to that data. The shared variable engine uses the PSP networking protocol, basically an updated Logos, as its native communication mechanism. The datasocket API, primatives, etc., now uses PSP as its default communication mechanism - although it will still communicate with older datasocket devices. This API can be used to read/write to shared variables when the identity of the variable is unknown at edit time.

There is also a new node for the block diagram called the shared variable, think local/global, which makes a connection to the engine and but also provide automatic wire-type updates, and linkages, if the shared variable configuration changes.

2-ish: Final numbers on performance are not available at this time.

3-ish: I'll try and get back to you.

[regisphilbin]

Just for clarification, Responses to my questions by the NI presenter are shown after the "A)"

[Surfman19]

hi,

i want to use shared variables between Compact Rio and Compact Vision 1455!

i created a real time project for the Compact Vision and add a shared variable to my project!

i write every second to the shared variable!!

but how can i use this shared variable in the VI of my compact rio project (real time) ??????????

i deployed all at the Compact Vision Project:

Deploying CompactVision (successfully deployed target settings)

Deploying ni_tagger_lv_ConnectBuffered.vi (3.84 K)

Deploying Trim Whitespace.vi (26.67 K)

Deploying Error Cluster From Error Code.vi (47.95 K)

Deploying Resolve Machine Alias.vi (11.86 K)

Deploying ResolveLogosURLMachineAlias.vi (12.64 K)

Deploying ni_tagger_lv_Write.vi (3.08 K)

Deploying ResolveOrUseCachedURL.vi (6.60 K)

Deploying NGwrite_imp.vi (8.40 K)

Deploying Untitled Library 1

Deploying Untitled Library 1:Variable1 \\172.16.0.4\Untitled Library 1\Variable1 deployed.

Deploying Untitled.vi (4.52 K)

i only can see the shared variable under tools-shared variable-variable manager!!! ;(

cu

[Phillip Brooks]

You need to define one of the RT targets to host the Shared Variable Engine.

I don't know how you do that, but the note below should help understand the SVE and help you decide where to host it based on your architecture....

http://zone.ni.com/devzone/conceptd.nsf/we...570F2007569EF#5