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| <== Date ==> | <== Thread ==> |
|---|
| Subject: | Re: Convertion for asynFloat64 |
| From: | Andrew Johnson <[email protected]> |
| To: | <[email protected]> |
| Date: | Tue, 19 Nov 2013 12:53:44 -0600 |
Hi Mark,The return value from an ao device support's init_record() routine doesn't cause LINR to be changed at all, it only affects whether the RVAL field value gets propagated back to the VAL field at startup. However unless the device's write_ao() routine actually looks at the LINR field, the user may set it without that having any affect on the value that gets passed to the driver.
In most cases the unit conversion and adjustment fields do not affect the values output or input by device support that takes or return the value in engineering units. Device support *may* use the values in those fields (ESLO, EOFF, ASLO, AOFF etc) if the author wants to, but I can't think of any that actually do so. They would have to duplicate some of the code from the record though, since its calculations only go to/from a 32-bit integer value in RVAL, thus losing data. I could see that as being useful for this kind of case, but documentation for the device support should make it clear for users that it is doing this.
- Andrew On 11/19/2013 11:57 AM, Mark Rivers wrote:
I don’t think you can do these types of conversions with the asynFloat64
device support for the ao record. devasynFloat64.c::initAo always
returns 2, which means “do not convert”. In aoRecord.c that means that
LINR is always left at the default value of menuConvertNO_CONVERSION.
So this means that the ao record never does any conversions with the
asynFloat64 deice support.
Mark
*From:*[email protected]
[mailto:[email protected]] *On Behalf Of *Benoit
*Sent:* Tuesday, November 19, 2013 11:16 AM
*To:* [email protected]
*Subject:* Convertion for asynFloat64
Hi,
I would like to use mV in my EPICS folder and send V to my driver.
I have done conversion correctly using asynInt32 type but it doesn't
work with asynFloat64.
Do you have any suggestion?
record(ao, "$(S):$(D)_$(C):CavVoltSet")
{
field(DTYP, "asynFloat64")
field(OUT, "@asyn($(PORT),$(ADDR),$(TIMEOUT))cavvolt")
field(PINI, "YES")
field(LINR,"SLOPE")
field(ESLO,"0.001")
field(PREC, "2")
}
I have try with
field(LINR,"SLOPE")
field(ASLO,"0.001")
and also with
field(LINR,"LINEAR")
field(EGUF,"1000")
field(EGUL,"0")
But nothing seems to change when I receive my value in my asynPortDriver.
Regards,
--
Benoit RAT
www.neub.co.nr <http://www.neub.co.nr>
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