Hi:
> newport IOC includes some records of the type
> mm4006:m11.HOMF
> mm4006:m11.MOVN
It’s
different.
There are
records with fields, and channels with properties.
A record X
might have fields like VAL, EGU, PREC, SEVR, STAT, TIME, …
A channel
has properties value, units, precision severity, status,
time stamp, …
When you
have a channel “X”, it connects to a record of the name “X”.
The value
property of the channel is set from the VAL field of the
record, units from EGU, precision from PREC, severity from
SEVR, …
This
separation of records/fields from channels/properties was an
early EPICS design decision.
It allows
you to have a channel that looks the same no matter if the
record is an AI, AO, CALC, LONGIN, … record.
In fact the
record type could change between AI and CALC, the client
doesn’t need to care.
In
principle, each field of a record could become a channel.
Just “X” is
really the same as “X.VAL”.
“X.SCAN”
will get you a channel where the value is set from the SCAN
field of the record, the value range is “0-Passive, …” for
the scan options. How the properties of the channel are
mapped to the fields of the record depend on internals of
the record.
In your
example, “mm4006:m11” is the record. If you create a
channel for
“mm4006:m11”, you get
VAL, the desired motor position. You could also use ““mm4006:m11.VAL” to make
that explicit.
“mm4006:m11.RBV” would get the current
motor position.
“mm4006:m11.HOMF”
is some value related to homing, I think.
Ø if I put (for example) mm4006:m11.HOMF and mm4006:m11.MOVN as PV I find two distinct
PVs...
Yes, and it’s perfectly fine to have
multiple channels for various fields of a motor record.
> if I stop the IOCs, .. CaLab info.vi .. give me the last values read
That’s a bug in CaLab, it seems. Channel
Access does give you a “disconnected” status as you can check
via the “camonitor” command line tool.
-Kay
Hi all, I have
some problems with CaLab, necessary to integrate
epics with a LabView interface. In particular now I
have two big problems: 1) i don't understand how to
use multiple field in the same CA. For example, my
newport IOC includes some
Hi all,
I have some problems with CaLab, necessary to integrate epics with a
LabView interface. In particular now I have two big problems:
1) i don't understand how to use multiple field in the same CA. For
example, my newport IOC includes some records of the type
mm4006:m11.HOMF
mm4006:m11.MOVN
etc...
CaLab Put.vi does not include the field. What do I do? if I put (for
example) mm4006:m11.HOMF and mm4006:m11.MOVN as PV I find two distinct
PVs...
2) I am trying to generate a monitor of the various IOCs. When starting
LabView there is no PV (via CaLab info.vi). If I start the IOCs I see
the PVs. However if I stop the IOCs, via command prompt (caget etc...) I
do not see (obviously) the active CA, while via CaLab info.vi the CA are
still active and give me the last values read. Even after a reset of PV,
using CaLab_Disconnect.vi, I still see the active CAs with the last
value read. Where am I going wrong?
Dariush
--
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Dr. Dariush Hampai, PhD
INFN - LNF
X-Lab Frascati
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Italy
Mail Address:
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