SAM Join Processor with Window Interval <1 second

[#1]

I am using the Join Processor in SAM to join multiple streams of simulated measurement Data from multiple machines into one stream, where each message contains the entire data for one machine at a given time. The problem is: The data is generated 4x per second, and I can not make the window interval for the Join processor less than 1 second, because I cannot enter a "," symbol into the processor, and when entering a "." and then closing and re-opening the processor, it is broken. This leads to every data message being joined to multiple messages from timestamps that are close, but not the same as the one from the previous data. Is there a way to set the Window Interval <1 second? Or is there an efficient workaround?

[#2]

which format does timestamp field accepted Streamining analtics manager ?

I am assume milliseconds from epoch