Status of system.tag.write to OPC tags

I am using system.tag.writeAll to write values to multiple OPC tags. The result shows successful writes for all tags (ie. all result values are 1) yet if my script reads the tags again to verify the write the old tag values are returned. Eventually the new tags values do update.

I’m assuming this is because a successful write is considered a successful write to the OPC server and that’s it? In what case would this function return a pending result?

If it is an async write that probably means that

1 = the tag exists and we spun up the thread,
0 = tag not there,
2 = uhhh, tag is there but we don’t have time to start a thread?