Experimental Physics and
Industrial Control System

Kay-Uwe Kasemir <[email protected]> · Fri, 17 Nov 2006 10:24:53 -0500

On Nov 17, 2006, at 09:49 , Lecorche Eric wrote:
Hi,
As we are starting our new Spiral2 project, I am now gathering some
pieces of information in order to establish naming conventions both
for devices and Epics records and taking into account habits
inherited from the existing Ganil installation.
I already got a document from Diamond describing such naming
conventions but I would be interested by having others coming from
other labs.
Can some labs send me some documents relevant for this topic ?

Hello Eric:
Whatever you do, write your naming standard
like a computer language definition, for example using BNF:
 <name> ::= <system> ":" <device> ":" <signal>

<system> ::= <system-id> <system-instance> "-" <subsystem-id>
<subsystem-instance>

<system-instance> ::= "" | "_" <instance>

<instance> ::= <integer> | <integer> <a-to-z>

...
An additional, verbose, more human readable explanation is nice,

but allow no misconception about the use of upper/lower case, '_' or
':',

or the structure of instance numbers.
This asserts that you get parsable names, which you'll need
for name-related tools. Actually, try to write a name parser right away,
for example in perl, to
a) check if your naming standard allows parsing
b) have such a tool to check names as soon as the first person tries
   to define the first process variable.
That way, you might avoid ending up with names like
DTL_Xyz:Gadget105:Value, wondering:

Is this the 105th gadget of the overall drift tube linac, or the 5th
gadget on DTL #1?

How do I write a regular expression that gives me all the devices on
DTL #2?
-Kay

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System