Re: [EXTERNAL] Support for DBR_INT64 missing in caget/camonitor?

["Kasemir, Kay via Tech-talk" <tech-talk@aps.anl.gov>]

Depends on the value.

CA sends the data as a double, so you get ~52 bits of information which are then scaled, not all 64 bits.

Note how ‘-f 0’ shows the wrong number, the lower bits in the hex number are basically zeroed.

 

$ pvput large 0x1234567812345678

New : 2025-07-24 10:06:55.607  1311768465173141112 

 

$ pvget large

large 2025-07-24 10:06:55.607  1311768465173141112 

 

$ caget -lx large

large                          0x7FFFFFFF

 

$ caget -f 0 large

large                          1311768465173140992

 

$ python3

>>> hex(1311768465173140992)

'0x1234567812345600'

 

 

 

 

 

On 2025-07-24, 9:55 AM, "Heinz Junkes (FHI)" <junkes@fhi-berlin.mpg.de> wrote:

I can also read the value with channel access camonitor/caget with -f 0 shows it correctly ;-)

 

(base) hactar:Db junkes$ camonitor -f 0 PPB:DOOR:WIEGAND:1:_data

PPB:DOOR:WIEGAND:1:_data       2025-07-24 15:52:15.150886 0

PPB:DOOR:WIEGAND:1:_data       2025-07-24 15:52:35.552332 6242213385

PPB:DOOR:WIEGAND:1:_data       2025-07-24 15:53:00.685626 9745890313

 

Heinz

 

> On 24. Jul 2025, at 14:26, Kasemir, Kay <kasemirk@ornl.gov> wrote:

>

> For what it’s worth, you can read INT64 with PV Access.

> Doesn’t mean you need to change everything over to PVA. Using CS-Studio, you may keep all your displays in Channel Access, but just for that one PV use “pva://PPB:DOOR::WIEGAND:1:data” to read it via PV Access.

>   On 2025-07-24, 6:01 AM, "Tech-talk" <tech-talk-bounces@aps.anl.gov> wrote:

> All right, thanks for the clarification. I understand that this is not possible.

> Heinz

>   > On 24. Jul 2025, at 11:46, Dmitry Yu. Bolkhovityanov <D.Yu.Bolkhovityanov@inp.nsk.su> wrote:

> > > Hi!

> > > Lack of INT64/UINT64 is not caget/caput/camonitor problem.  These types are missing in the Channel Access protocol and it would be not an easy task to add them.

> > > Look into db_access.h file: there are 8 "basic" DBF_nnn types and a number of DBR_nnn types, of which first 8 are aliases to DBF_nnn, while the rest are 8x DBR_STS_nnn, 8x DBR_TIME_nnn, 8x DBR_GR_nnn, 8x DBR_CTRL_nnn, plus a number of exotic ones, like DBR_STSACK_STRING.

> > > It is hardly possible to extend the CA type nomenclature without breaking compatibility in some way.

> > > > With best regards,

> > Dmitry

> > > > > On Thu, 24 Jul 2025, Heinz Junkes (FHI) via Tech-talk wrote:

> > >> Hi,

> >> >> I have an int64in record and cannot read the decimal value via caget/camonitor.

> >> >> epics> dbpr PPB:DOOR::WIEGAND:1:data,7

> >> ACKS: NO_ALARM      ACKT: YES           ADEL: 0             AFTC: 0

> >> AFVL: 0             ALST: 8591023625    AMSG:               ASG :

> >> ASP : PTR (nil)     BKLNK: ELL 0 [(nil) .. (nil)]           BKPT: 00

> >> DESC: Wiegand w1    DISA: 0             DISP: 0             DISS: NO_ALARM

> >> DISV: 1             DPVT: PTR 0x55a303ba30

> >> DSET: PTR 0x7fb81f00c0                  DTYP: wiegandInt64in

> >> EGU :               EVNT:               FLNK: CONSTANT      HHSV: NO_ALARM

> >> HIGH: 0             HIHI: 0             HOPR: 0             HSV : NO_ALARM

> >> HYST: 0             INP : CONSTANT 1    LALM: 8591023625    LCNT: 0

> >> LLSV: NO_ALARM      LOLO: 0             LOPR: 0             LOW : 0

> >> LSET: PTR 0x55a303b3a0                  LSV : NO_ALARM      MDEL: 0

> >> MLIS: ELL 0 [(nil) .. (nil)]            MLOK: c0 b8 03 a3 55 00 00 00

> >> MLST: 8591023625    NAME: PPB:DOOR::WIEGAND:1:data          NAMSG:

> >> NSEV: NO_ALARM      NSTA: NO_ALARM      OLDSIMM: NO         PACT: 0

> >> PHAS: 0             PINI: YES           PPN : PTR (nil)     PPNR: PTR (nil)

> >> PRIO: LOW           PROC: 0             PUTF: 0

> >> RDES: PTR 0x55a2fdc0a0                  RPRO: 0

> >> RSET: PTR 0x7fb81c0d40                  SCAN: I/O Intr      SDIS: CONSTANT

> >> SDLY: -1            SEVR: NO_ALARM      SIML: CONSTANT      SIMM: NO

> >> SIMPVT: PTR (nil)   SIMS: NO_ALARM      SIOL: CONSTANT

> >> SPVT: PTR 0x55a3042840                  SSCN: 65535         STAT: NO_ALARM

> >> SVAL: 0             TIME: 2025-07-24 10:33:53.999485865     TPRO: 0

> >> TSE : 0             TSEL: CONSTANT      UDF : 0             UDFS: INVALID

> >> UTAG: 0             VAL : 8591023625

> >> >> With caget/camonitor I get the value displayed as float:

> >> >> (base) hactar:~ junkes$ caget PPB:DOOR::WIEGAND:1:data

> >> PPB:DOOR::WIEGAND:1:data       8.59102e+09

> >> (base) hactar:~ junkes$ camonitor PPB:DOOR::WIEGAND:1:data

> >> PPB:DOOR::WIEGAND:1:data       2025-07-24 10:33:53.999486 8.59102e+09

> >> >> >> The attempt to specify the type is not possible:

> >> >> (base) hactar:~ junkes$ caget -d DBR_INT64 PPB:DOOR::WIEGAND:1:data

> >> Requested dbr type out of range or invalid - ignored. ('caget -h' for help.)

> >> PPB:DOOR::WIEGAND:1:data       8.59102e+09

> >> >> Gruss Heinz