system.tag.writeSynchronous in Ignition 8

Hi everyone,

We have just upgraded a project from Ignition 7.9.10 to Ignition 8.

In the project we have a lot of scripts that use the system.tag.writeSynchronous function to write to tags.

After testing using Ignition 8 it looks like the system.tag.writeSynchronous and system.tag.write functions still works even though they are no longer listed in the Ignition user manual for version 8. The only thing we had to change was changing the timeout unit from seconds to miliseconds.

My question is can we keep on using system.tag.writeSynchronous function in the scripts? (it will be great if we can keep on using it) or is system.tag.writeSynchronous and system.tag.write going to be completely phased out at some stage in newer versions? And if it’s not recommended to keep on using these two functions then which of the new tag write function should we change to? As I see in the Ignition 8 manual the system.tag.writeAsync function seems to be quite different?

Many thanks.

I had asked a similar question whether synchronous read and write will be deprecated in version 8 or not. I was told that they will internally use the asynchronous calls but they will continue to be supported for backward compatibility so that existing code of many users will not break. However they are not documented so that people use the async versions. Someone from IA may confirm please. Also please confirm if it will have an impact on the performance (using sync vs async in new versions of Ignition).

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They won’t stop working.

writeSynchronous has been replaced by writeBlocking.


writeBlocking has return values from the function and writeSynchronous does not.
I tested these on the script console and I did notice some difference in response time of the over all execution of a same script.
Question: Is there a documented/known difference in the performance between these 2 functions ?
I am interested to know if one can finish writing faster than the other.

There is no performance difference, they have the same underlying implementation.