It's Control characters for a simple Serial string like Rick500 mentioned.
It sends a bit status request (Message Type I) to one of our controllers at work to request ..well the status of 2 output bits we supply to a host. 0 is a decimal representation of the binary output.
Get it Shecky?
And as far as too much time on my hands, that is true too.
This is a nice "cap" one of the guys had to wear over the baseball cap they made him wear in one of the plants. It was a japanese plant. God those people are weird! Can;t just make a Hard Hat with your logo on it!