Experimental Physics and
Industrial Control System

"Purcell, J. David" <[email protected]> · Thu, 05 Aug 2010 15:10:52 -0400

I'd hate to disagree with the well placed source as he's probably my boss.  But the convention isn't the reason there are names that aren't up to par.  The reason is that we were never told to be consistent.  That's my polite way of saying that management at SNS never enforced naming.  IOC engineers were up against time constraints and naming wasn't a concern.  I personally did all of the naming for the diagnostics group.  But my interpretation of the rules weren't the same as other groups.   And then within other groups, individual engineers were allowed to come up with their own interpretations.   

There are different interpretations that all allow different "valid" names.  But lack of enforcement also allowed names to also be flat out wrong.  And now those names are imbedded and we have no real plan on how to fix them.  In the beginning, if we were told to fix the wrong names, there might have been an effort to get to one interpretation of the convention.  

One thing I will say is that everyone in diagnostics and at SNS who cares about diagnostic devices/signals, knows how diagnostic naming was done and how to read it.  Not to insult our guests but a tour group member doesn't have to know exactly where BLM130 is or what exactly DTL_Diag:BLM130 means.

The best advice I would give would be to make sure that what you decide on is what you do.   Have a mechanism in place to check the names so that you can be picky about it.  And have a stick big enough laying around that you can enforce it.

As to the list below, one thing you need to remember is that those are signal names and not device names.  Everything after the second colon is the PV name and because case matters any variation of case/letters is a different PV.  Also, as I was the guy naming BLM130, I would have known that the "_" between the device type "BLM" and the instance "130" was a no-no.  And I would only have made "Diag" the system indicator (the first part of a name) if the device was a global diagnostic device.   So, DTL_Diag:BLM130 is the only valid name for that device.

To answer the original question, I'm for mixed case.  No spaces or underscores or dashes or ....

Dave Purcell

On Aug 5, 2010, at 1:44 PM, Steven M. Hartman wrote:

> Dalesio, Leo wrote:
> 
>> DTL_Diag:BLM130:MPSTripLimitRad
>> -------------------------------------
>> Is this the Beam Loss Monitor #30 in Cell #1
>> or
>> Beam Loss Monitor #0 in Cell #13
>> ????
> 
> 
> Yes, that is some of the problem with the SNS naming standard.
> 
> These would all be "valid" names for this device:
> 
> DTL_Diag:BLM130:MPS_Trip_limit_Rad
> DTL_Diag:BLM130:MPSTripLimitRad
> DTL:BLM130:MPSTripLimitRad
> DTL_Diag:BLM130:MPS_TripSet
> Diag_DTL:BLM130:MPSTripLimitRad
> DTL_Diag:BLM_130:MPSTripLimitRad
> Diag:BLM_DTL130:MPSTripLimitRad
> DTL_Diag:BLM130:MPS_TripLimitRad
> DTL_Diag:BLM130:MPS_Trip_Limit_Rad
> DTL_Diag:BLM130:MPS_trip_limit_Rad
> DTL_Diag:BLM130:MPS_TripLimit_Rad
>  . . . and most of the various permutations that you can think of.
> 
> And then you also need to remember that for the DTL, BLM130 would 
> refer to the only BLM in position 30 within DTL section 1, while 
> in the SCL, BLM13b would refer to the second BLM within SCL 
> section 13.
> 
> 
> 
> -- 
> Steven Hartman
> [email protected] || 865-466-6473

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System