Experimental Physics and
Industrial Control System

Rod Nussbaumer <[email protected]> · Fri, 13 Sep 2013 06:27:46 -0700

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: [email protected] [mailto:[email protected]] 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.

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System