Can I use the timestamp of a Network published global variable to reduce network traffic?

[mark3545]

I would like to use a couple of network-published global variables that will contain large clusters of data.  I want to host them on one device but read them from several - consider a distributed control system.  The data will update very infrequently, but, when it does, I want all my HMIs to know quickly.  I can have all the HMIs just read the data 4x/second (that would be fast enough) but I was wondering if there is a more elegant solution (still using global variables).  If I read only the timestamp 4x/second from each of the HMIs, compare it to the last read, and then poll the whole variable only if the timestamps are different, will that require less resources than just grabbing the whole variable every time?  In other words, does reading the timestamp use the same amount of resources as reading the whole variable?

With really simple code, assuming the "Setup Data" cluster is quite large, does....

...get me any advantage over...

[crossrulz]

Nope, that won't help you.  The shared variables are only published when there are updates.  Each reader already has their own copy of the data and it only gets updated when the new values are published.

[mark3545]

So that means they are already doing what I want anyway, right?  If the reader only gets updated when the writer changes it, I can poll it as often as I want without increasing traffic, correct?

[crossrulz · Accepted solution]

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@mark3545 wrote:

So that means they are already doing what I want anyway, right?  If the reader only gets updated when the writer changes it, I can poll it as often as I want without increasing traffic, correct?

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That is correct.