Where is the SAMA diagram standard?
David Ferguson
Scientific Apparatus Manufactures Association (SAMA)
standard for drawing process control symbols.
Does anyone know if an updated standard is available on the Internet?
Thanks...David
Walter Driedger
The Scientific Apparatus Makers Association no longer exists.
Actually I find the SAMA diagrams relics of an earlier time when every
component in a control scheme was a piece of hardware and every
feature was an option that had to be specified, bought and paid for
separately. For example, in a SAMA diagram I can draw a PID
controller with separate little parts for P, I, D, auto/manual
transfer, remote setpoint, sqrt extraction, high alarm, deviation
alarm, output limiting, etc., etc., etc. Every controller in a DCS
has every one of these features available. There is no need to draw
diagrams of them. If fact they have far more features in the
parameter list than a SAMA diagram could ever cover.
What I use is a simple bubble diagram, such as ISA has for P&IDs, to
show how points are interconnected. Then I configure each point with
all the features it requires.
Walter.
Graham Wright
<86n8bl$r2e$1...@ssauraab-i-1.production.compuserve.com>:
>We have a old (1980s) copy of the
>
> Scientific Apparatus Manufactures Association (SAMA)
>
>standard for drawing process control symbols.
>
>Does anyone know if an updated standard is available on the Internet?
>
>Thanks...David
>
>
I also have a copy of this standard. I did some checking around 8-10 years
ago and found that no body supported it at the time. I consider that the
SAMA standard is the best available in this field and would like to see it
taken up by some body (maybe the ISA).
The copy you have is likely to be the latest.
Graham Wright
Francis
diagrams are not longer needed.
OK, so the components are now soft instead of hard, but we still need
diagrams to shown how they fit together as much as we used to. And the
typical ISA bubbles shown on most P&ID are often gross simplifications that
can lead to DCS software configuration problems unless a further step such
as a SAMA diagram is provided.
SAMA can also be seen as a predecessor of IEC1131/3 Function Block diagrams
if you like.
Francis
Ian Milne
> We have a old (1980s) copy of the
> Scientific Apparatus Manufactures Association (SAMA)
> standard for drawing process control symbols.
> Does anyone know if an updated standard is available on the Internet?
>
> Thanks...David
The SAMA symbology is being integrated into ISA S5.1
"Instrumentation Symbols and Identification". This standard
is currently under review with an expected year 2000 release.
Refer to: <http://www.isa.org/sc/committee/1,1512,14,00.html>
Questions should be directed to the ISA Staff Contact at
<crob...@isa.org>
Regards,
Ian Milne
John Popelish
I agree that the bubble diagrams are not at all adequate to convey
necessary configuration information to those build the software but
more importantly, they do not communicate important control concepts
to future engineering consideration. We replaced a pneumatic system
with a DCS control system on a group of boilers, and documented the
approach with SAMA diagrams. By the time we got through 2 or three
iterations of upgrades and modifications, we had come up with a custom
set of symbols that displayed enough details to allow a controls
engineer to understand the signal flows well enough to proceed with
tuning, and added blocks of noted that detailed configuration details
that were needed to construct the system. The drawings include an
explanatory sheet that covers the symbology as it was actually used,
since it is no longer standard.
What I would like to see is a system of documentation that links
several layers or presentations that address all aspects of program
documentation, from operator training (basic command flow) process
engineering (tuning, alarms and exception handling including fuzzy
logic and neural net concepts), and detailed configuration choices and
entries, for the data entry types, I/O wiring diagrams for the
instrument guys, as well as theory of operation text. I am the guy
who must be able to wade through all those aspects (I have a lot of
hats). This would make it much easier to manage change in these ever
more complex control systems.
I don't think such a documentation system exists today.
--
John Popelish
les crowley
programming tool that often follows the orginal SAMA philosophy of function
block configuration. Bailey came out with one of the first versions.
Fisher Provox is based on the SAMA function block methodology. Moore 352's
even based their configuration on this same philosophy.
I rather like it. One of the respondents in this thread referenced IEC1131.
The function block part of this spec does closely resemble this trend.
Modicon Concept follows this method and does an outstanding job of it.
Allen Bradley Control Logix and Honeywell Plantscape have jumped on board.
I believe this trend will stand the test of time.
Francis <f...@cwcom.net> wrote in message
news:WfWj4.3786$PG6.63753@news2-hme0...
Francis
know what you think.
Francis
www.controldraw.co.uk
Ken Duckworth
makes a good way to plan and document control loops. I still use it for
this purpose.
Walter Driedger wrote in message <388FCE25...@cadvision.com>...
>David:
>
>The Scientific Apparatus Makers Association no longer exists.
>
>Actually I find the SAMA diagrams relics of an earlier time when every
>component in a control scheme was a piece of hardware and every
>feature was an option that had to be specified, bought and paid for
>separately. For example, in a SAMA diagram I can draw a PID
>controller with separate little parts for P, I, D, auto/manual
>transfer, remote setpoint, sqrt extraction, high alarm, deviation
>alarm, output limiting, etc., etc., etc. Every controller in a DCS
>has every one of these features available. There is no need to draw
>diagrams of them. If fact they have far more features in the
>parameter list than a SAMA diagram could ever cover.
>
>What I use is a simple bubble diagram, such as ISA has for P&IDs, to
>show how points are interconnected. Then I configure each point with
>all the features it requires.
>
>Walter.
>
John Popelish
Francis, this looks like an impressive chunk of software. It will take
a while till I can give it a good look. Are you planning a future
version of this for sale?
--
John Popelish
Sent via Deja.com http://www.deja.com/
Before you buy.
Francis
It is in it's alpha testing stage at the moment.
Have a look at What's coming on the web site to get an idea of what it does.
Francis
www.controldraw.co.uk
John Popelish <jpop...@rica.net> wrote in message
news:8787rd$j0k$1...@nnrp1.deja.com...
HBullock
to do ours and it allows for linking of CAD drawings with Configuration
sheets, Operation notes, etc. Its a nice package for allowing the
connection of the required info to handle complex configuration problems.
As for a symbolic representation of all the possible configurations. Ugh.
--
"Standards are like tootbrushes. Everyone agrees they are a good thing.
But no one wants to use someone elses."
John Popelish <jpop...@rica.net> wrote in message
news:3890C7A7...@rica.net...
> Francis wrote:
> >
> > I disagree about them being "relics of an earlier time " and that the
> > diagrams are not longer needed.
> > OK, so the components are now soft instead of hard, but we still need
> > diagrams to shown how they fit together as much as we used to. And the
> > typical ISA bubbles shown on most P&ID are often gross simplifications
that
> > can lead to DCS software configuration problems unless a further step
such
> > as a SAMA diagram is provided.
> > SAMA can also be seen as a predecessor of IEC1131/3 Function Block
diagrams
> > if you like.
> > Francis
>
> I agree that the bubble diagrams are not at all adequate to convey
> necessary configuration information to those build the software but
> more importantly, they do not communicate important control concepts
> to future engineering consideration. We replaced a pneumatic system
> with a DCS control system on a group of boilers, and documented the
> approach with SAMA diagrams. By the time we got through 2 or three
> iterations of upgrades and modifications, we had come up with a custom
> set of symbols that displayed enough details to allow a controls
> engineer to understand the signal flows well enough to proceed with
> tuning, and added blocks of noted that detailed configuration details
> that were needed to construct the system. The drawings include an
> explanatory sheet that covers the symbology as it was actually used,
> since it is no longer standard.
>
> What I would like to see is a system of documentation that links
> several layers or presentations that address all aspects of program
> documentation, from operator training (basic command flow) process
> engineering (tuning, alarms and exception handling including fuzzy
> logic and neural net concepts), and detailed configuration choices and
> entries, for the data entry types, I/O wiring diagrams for the
> instrument guys, as well as theory of operation text. I am the guy
> who must be able to wade through all those aspects (I have a lot of
> hats). This would make it much easier to manage change in these ever
> more complex control systems.
>
> I don't think such a documentation system exists today.
> --
> John Popelish