presignal

adj

1. (not-comparable)Before a signal.

   “Another experiment showed that presignal information about which of two frequencies was to be presented aids detection considerably, but such information does not entirely eliminate the decrement.”

   “Mean shocks per minute for each of the four Ss during a 1-rnin presignal period, during successive 20sec of signal presentation, and during a 1-min postsignal period.”

   “Signals to subjects to forget presignal items completely eliminated the proactive interference postsignal items would normally suffer from the presignal items.”

   “Therefore, a presignal area was determined based upon thresholds and/or indicator values, whether positive or negative. Once an indicator reaches its defined presignal area, it has been primed to await its firing signal.”

noun

1. A signal that occurs before some occurrence, as a warning or to trigger an automatic preparation.

   “A presignal gets the moving cars back of the intersection off to the same flying start as the stopped lead vehicles. Von Stein has also used presignals in Dusseldorf and in other parts of Germany to create "time islands" for streetcars that must stop where there is no room for loading islands.”

   “In this case, a presignal from the ATS could be interfaced with the elevator controls for that purpose.”

   “A presignal ahead of the streetcar stop allows the streetcar to pass into the unloading zone only after all the nonrail-bound traffic has left.”