Re: BiRa Ethernet Power Supply Controllers

[Rod Nussbaumer <bomr@triumf.ca>]

Thanks, Stephanie and others who have responded.

I should state that the intended purpose for using these controllers is 
to apply their built in closed loop control of the load current to 
improve on the stability, long term and short term, of the power supply 
being controlled. We're presently looking at Lambda Genesis series PS's 
in this application. There is a cost-saving consideration in this 
choice, over using more tightly spec'd power supplies, and we're looking 
at a quantity of about 6.
Not at present, but I can foresee a time when there may be a requirement 
to use a closed loop scheme to control magnet field using an external 
gauss meter in the loop, possibly using the EPICS PID record. Should I 
be concerned about any bad interaction between that loop control and the 
inner loop within the power supply controller? This may be impossible to 
know without inside knowledge of the power supply controller, but 
perhaps someone has such information.
Has anyone used any other alternative system to achieve greater load 
current stability? There is a concern about the ability to tightly 
control load current at very low currents. Does this or any other system 
impact that capability?
Thanks all.

   ---   rod.


On 09/12/2013 12:44 PM, Allison, Stephanie wrote:
> Hi Rod,
>
> At SPEAR, we use the EPSCs for our main power supplies (unipolar power supplies for quads, bends, etc, that don't need fast control).  The EPICS driver/device support is a bit non-standard (ie, doesn't use asyn - note the controller uses UDP) but works OK, at least on epics 3.14.11, RHEL6-64bit.  The software we use is here in case you want to take a look:
> ftp://ftp.slac.stanford.edu/groups/controls/soft/epics/etherPSC.tar.gz
> Sorry - there is no documentation in that tar file.  Maybe BiRa provides some documentation.
> (I don't know if this is the same software that BiRa provides).
>
> I will forward your email to the SPEAR power supply engineer who can fill you in on more detail.
>
> Stephanie Allison
>
> > -----Original Message-----
> > From: tech-talk-bounces@aps.anl.gov [mailto:tech-talk-bounces@aps.anl.gov] On Behalf
> > Of Rod Nussbaumer
> > Sent: Wednesday, September 11, 2013 4:39 PM
> > To: epics Techtalk
> > Subject: BiRa Ethernet Power Supply Controllers
> >
> > Hi all.
> >
> > Has anyone had any exeprience with BiRa Ethernet Power Supply
> > Controllers? BiRa is advertising that SLAC has used them, so I would be
> > happy to hear from anyone there with some firsthand knowledge.
> >
> > What is the nature of the EPICS support? Being ethernet, I was hoping
> > for something SCPI-like, but the datasheet doesn't suggest that.
> >
> > Our power supply group would also like to contact anyone that may have
> > knowledge of the hardware, installation, and those aspects of these devices.
> >
> > Thanks.
> >
> >
> > Rod Nussbaumer
> > ISAC Controls, TRIUMF
> > Vancouver, Canada.