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Sat, 18 Jul 1998 13:12:12 -0700
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Hi
I was just browsing the Team Ada archives and noticed some emails from July
1997 that mentioned how good it would be if there were commercial railroad
systems in the US done in Ada. So I am forwarding the message below to
you. (I had sent this message to be posted under the Ada Success Stories
about 1 year ago, however to the best of my knowledge it has not yet been
posted there yet). Since i wrote this text, we have completed 1 more RR
project in Ada and started a new big one, also in Ada.
Safetran Systems Corporation (USA) have completed a commercial Ada
based product for the rail-road market. This product is used to
replace pole-lines for communication of vital signalling information.
Presently vital signalling information is transmitted between 2 points
over pole-lines or cables. Our product replaces these with
spread-spectrum radios.
The product reads vital information at a location and transmits data
over spread-spectrum radio (the radio software is not in Ada). The
product is safety-critical, embedded and hard real-time in nature and
has been implemented in Ada83 with about 30,000 lines of code. Ada has
been used for the entire software in this product including the vital
control software, an integrated event recorder, error
detection/handling and communications protocols using RS-232 and a 7
layer OSI based communication system over twisted-pair.
The implementation of this product was done in the Ada language for
many reasons. One of the most important reasons was Ada's support of
software engineering principles and being able to write maintanable,
readable, easily re-usable and efficient code. While a language alone
cannot guarantee all these attributes, it certainly has a strong
impact and can encourage a particular (better) style of coding.
The excellent concept of packages in Ada allowed us to modularize our
software easily with clean, clear interfaces. This allowed us to
manage changes easily without having developers using old/incorrect
interfaces. Hence when the software came together during final
integration all the interfaces worked first time without any problems.
Among other Ada features which were very useful are a very readable
syntax, strong/flexible type checking and generics. These allow many
more
errors to be picked up by a compiler rather than debugging them during
run-time resulting in substantial saving of time and cost.
It is difficult and time consuming to go over each and every feature
of Ada that saves developers time/cost and adds to re-use and
maintainability, as the whole Ada programming environment & philosophy
is geared towards doing just that - doing software with engineering
rigour. It has been said that Ada is not just a programming language
but a whole environment and we agree with that. As mentioned earlier a
language cannot force you to do design or capture requirements better
however it can have a significant positive impact on a number of issues
in
software development and Ada tries to tackle these issues.
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Rakesh Malhotra * *
Safetran Systems Corporation, California, USA * *
Phone : +(1)(909) 987-4673 Ext-389 Fax: +(1)(909) 466-4177 * *
Email : [log in to unmask] *
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