Experimental Physics and
Industrial Control System

"Leblanc, Gregory via Tech-talk" <tech-talk at aps.anl.gov> · Mon, 20 Mar 2023 15:46:37 +0000

Thanks Dirk that got me on the right track.  I changed the record in my .db file to read:

 record(ao, "$(P)$(R)writeOutput1") {
    field(DESC, "Write to Test Output 1")
    field(DTYP, "stream")
    field(PREC, "3")
    field(EGU,  "Volts")
    field(SCAN, "Passive")
    field(OUT, "@devKS_34980A_EPICS.proto setSourceVoltage(%E,2001) $(PORT) $(A)" )
    field(PINI, "YES")
    field(VAL, "0")
}

Which has done the trick.  
     Greg

> -----Original Message-----
> From: Zimoch Dirk <dirk.zimoch at psi.ch>
> Sent: Monday, March 20, 2023 10:51 AM
> To: Leblanc, Gregory <leblanc at ohio.edu>; tech-talk at aps.anl.gov
> Subject: [External] Re: Output records in StreamDevice
> 
> Use caution with links and attachments.
> 
> Hi Greg,
> 
> You use % formats just as for the inputs:
> 
> setSourceVoltage {
>     out "source:voltage \$1,(@\$2) %E";
> }
> 
> 'out' works like printf() while 'in' works like scanf().
> 
> Dirk
> 
> 
> On Mon, 2023-03-20 at 14:44 +0000, Leblanc, Gregory via Tech-talk wrote:
> > Hi folks,
> >
> > I'm struggling a bit to wrap my head around how to use output records in
> StreamDevice.  I'm missing the link between the value going into the PV and
> sending that value to my device.
> >
> > Background: I'm using EPICS base 7.0 checked out from GIT, running on
> CentOS 7. I've also installed asyn, calc, and streamdevice from git.   I'm
> communicating with an HP/Agilent/Keysight 34980A mainframe over ethernet.
> I'm reading from the mainframe DMM without any issues.  Snippets of the
> protocol file and record file look like:
> >
> > getResistance {
> >     out "measure:resistance? \$1,\$2,(@\$3)";
> >     in "%E";
> > }
> >
> > And
> >
> > record(ai, "$(P)$(R)switcherMagnetVoltage") {
> >     field(DESC, "Switcher Magnet Voltage")
> >     field(DTYP, "stream")
> >     # field(SCAN, "1 second")
> >     field(SCAN, "Passive")
> >     field(INP,  "@devKS_34980A_EPICS.proto getVoltageDC(100,0.0001,1001)
> $(PORT) $(A)")
> >     field(EGU, "Volts")
> >     field(PINI, "YES")
> > }
> >
> > Where I'm stuck is on writing values to the mainframe to control the DACs.
> I've got a section of the protocol file that looks like:
> >
> > setSourceVoltage {
> >     out "source:voltage \$1,(@\$2)";
> > }
> >
> > Where the first parameter is the DC voltage (-16V to 16V), and the second
> parameter is the output channel to set.  I've written an AO record, which is
> where I think the problem is like this:
> >
> > record(ao, "$(P)$(R)writeOutput1") {
> >     field(DESC, "Write to Test Output 1")
> >     field(DTYP, "stream")
> >     field(PREC, "3")
> >     field(EGU,  "Volts")
> >     field(SCAN, "Passive")
> >     field(OUT, "@devKS_34980A_EPICS.proto setSourceVoltage(3,2001)
> $(PORT) $(A)" )
> >     field(PINI, "YES")
> >     field(VAL, "0")
> > }
> >
> > From here, pvput to writeOutput1 will cause that output to get set back to 3V.
> The presentation at:
> > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Findi
> > co.fhi-
> berlin.mpg.de%2Fevent%2F52%2Fcontributions%2F578%2Fattachments%
> >
> 2F182%2F578%2FStreramDeviceIntroduction2020.pdf&data=05%7C01%7Clebla
> nc
> >
> %40ohio.edu%7Cd16f983379a545899fca08db29529519%7Cf3308007477c4a70
> 88893
> >
> 4611817c55a%7C0%7C0%7C638149206941740240%7CUnknown%7CTWFpbGZs
> b3d8eyJWI
> >
> joiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C300
> 0%7
> >
> C%7C%7C&sdata=7hpkZg9fvBdpAdP3V1DjBpH5Ouz6tq1CGdPHZRAW2Q0%3D&r
> eserved=
> > 0 has some AO records on page 24, but I still can't quite see how the
> > value gets from the AO record into the string that streamdevice is sending out.
> >
> > Any pointers on what I need to do are greatly appreciated,
> >      Greg
> >
> > P.S. More complete files are available at:
> > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgith
> >
> ub.com%2FleblancOUAL%2FKS_34980A_EPICS&data=05%7C01%7Cleblanc%40o
> hio.e
> >
> du%7Cd16f983379a545899fca08db29529519%7Cf3308007477c4a70888934611
> 817c5
> >
> 5a%7C0%7C0%7C638149206941896472%7CUnknown%7CTWFpbGZsb3d8eyJWI
> joiMC4wLj
> >
> AwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C
> %7C&s
> >
> data=oMfN%2FV%2FFOiutjdaJy1SWEMpGlVBFi9qeUi3FaYzVhtM%3D&reserved=
> 0
> >
> > --
> > Gregory Leblanc
> > Accelerator Engineer
> > Edwards Accelerator Lab - Ohio University
> > 123 University Terrace
> > Athens, OH 45701 USA
> > leblanc at ohio.edu
> > M: (401) 52-OUAL1 or (401) 526-8251
> >

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System