Value of the Network Shared Variable when the computer turns off

[jangel22]

Hi folks 

 

I'm working with NSV deployed in two computers (lets call them A and B), but I want to be able to make the value of the NSV in B false when the program exits in A or when this computer turns off.

 

Any idea of how make this?

 

PS. Excuse my english.

 

Thanks in advance

 

 

 

 

 

[JKSH]

Hi,

 

There are a few ways you can do this.

 

First way

Make the program in A write "true" to the NSV when it starts, and make it write "false" before it quits.

 

This is simple, but there is one disadvantage: If the program in A doesn't quit properly, then the value will stay "true". For example, if computer A loses power, the program stops running but it can't write "false".

 

Second way

Make the program in A write a value to the NSV every second. The program in B doesn't check the value, but it checks the timestamp. If the timestamp doesn't change for 5 seconds, then B sets a local flag to "false".

[crossrulz]

If computer A is hosting the NSV and it is not running, then B should get an error when it tries to read the variable.  With an error, I would expect the default values.  But it may be the last read value.  But you should be able to look for the error.