Path: utzoo!attcan!uunet!wuarchive!brutus.cs.uiuc.edu!rpi!uupsi!rodan!isr
From: isr@rodan.acs.syr.edu ( ISR group account)
Newsgroups: comp.realtime
Subject: Re: What is "real-time" really?
Keywords: Realtime, opinions
Message-ID: <2252@rodan.acs.syr.edu>
Date: 27 Feb 90 14:51:54 GMT
References: <98692@linus.UUCP> <1990Feb23.191100.18448@vicom.com> <1990Feb23.231250.19561@csuchico.edu>
Reply-To: isr@rodan.acs.syr.edu (Michael S. Schechter - ISR group account)
Organization: I can't write without a keyboard any more
Lines: 24


How about:
Real-time systems are those in which when looking at the states it goes
through s1..s2...s3..s4..s5..s6..s7.. etc, it is required that the system
be in a particular state Sn withing a time Tn of an event En. 

This seems to hold whether your talking about a balance being returned
within 5 seconds of a ATM request, or a value being output within half
a microsecond of a sensor firing, or even a payroll program finishing
within 3 hours of it's starting time. (After all, if it's going to
be run at midnight thursday night and has to be done by 3:15 am to
print the checks, its real-time)

On the other hand, if a system doesn't guarantee this, then I can't
see how it could be considered real-time.

Mike Schechter                  msschech@rodan.syr.edu
Systems Engineer
Institute for Sensory Research  isr@rodan.syr.edu


-- 
Mike Schechter, Computer Engineer,Institute Sensory Research, Syracuse Univ.
InterNet: isr@rodan.acs.syr.edu   Bitnet: SENSORY@SUNRISE