epics/epics-base
0
0
Fork 0
Code Issues Pull Requests Projects Wiki Activity

POD text updates to dbCommon and various record types

Browse Source
This commit is contained in:
Andrew Johnson
2021-08-10 20:35:19 -05:00
parent 72626cd5dd
commit 8175cc8e64
10 changed files with 197 additions and 136 deletions
Download Patch File Download Diff File Expand all files Collapse all files
modules/database/src/ioc/db/dbCommon.dbd.pod
+82 -71
View File
@@ -77,12 +77,12 @@ A set of periodic scan intervals
=back
Additional periodic scan rates may be defined for individual IOCs by making a
local copy of menuScan.dbd and adding more choices as required. Scan rates
should normally be defined in order, with the fastest rates appearing first.
Scan periods may now be specified in seconds, minutes, hours or Hertz/Hz, and
plural time units will also be accepted (seconds are used if no unit is
mentioned in the choice string). For example the rates given below are all
valid:
local copy of menuScan.dbd and adding more choices as required. Periodic scan
rates should normally be defined in order following the other scan types, with
the longest periods appearing first. Scan periods can be specified with a unit
string of C<second>/C<seconds>, C<minute>/C<minutes>, C<hour>/C<hours> or
C<Hertz>/C<Hz>. Seconds are used if no unit is included in the choice string.
For example these rates are all valid:
1 hour
0.5 hours
@@ -97,7 +97,7 @@ initialization (before the normal scan tasks are started).
The B<PHAS> field orders the records within a specific SCAN group. This is not
meaningful for passive records. All records of a specified phase are processed
before those with higher phase number. Whenever possible it is better to use
before those with higher phase number. It is generally better practice to use
linked passive records to enforce the order of processing rather than a phase
number.
@@ -109,23 +109,23 @@ The call to post_event is: post_event(short event_number).
The B<PRIO> field specifies the scheduling priority for processing records
with SCAN=C<I/O Event> and asynchronous record completion tasks.
The B<DISV> field specifies a "disable value". Record processing is
immediately terminated if the value of this field is equal to the value of the
DISA field, i.e. the record is disabled. Note that field values of a record
can be changed by database put or Channel Access, even if a record is
The B<DISV> field specifies a "disable value". Record processing cannot
begin when the value of this field is equal to the value of the DISA
field, meaning the record is disabled. Note that field values of a record
can be changed by database or Channel Access puts, even if the record is
disabled.
The B<DISA> field contains the value that is compared with DISV to determine
if the record is disabled. The value of the DISA field is obtained via SDIS if
SDIS is a database or channel access link. If SDIS is not a database or
channel access link, then DISA can be set via dbPutField or dbPutLink.
If the B<PROC> field of a record is written to, the record is processed.
The B<DISA> field contains the value that is compared with DISV to determine if
the record is disabled. A value is obtained for the DISA field from the B<SDIS>
link field before the IOC tries to process the record. If SDIS is not set, DISA
may be set by some other method to enable and disable the record.
The B<DISS> field defines the record's "disable severity". If this field is
not NO_ALARM and the record is disabled, the record will be put into alarm
with this severity and a status of DISABLE_ALARM.
If the B<PROC> field of a record is written to, the record is processed.
The B<LSET> field contains the lock set to which this record belongs. All
records linked in any way via input, output, or forward database links belong
to the same lock set. Lock sets are determined at IOC initialization time, and
@@ -135,15 +135,18 @@ The B<LCNT> field counts the number of times dbProcess finds the record active
during successive scans, i.e. PACT is TRUE. If dbProcess finds the record
active MAX_LOCK times (currently set to 10) it raises a SCAN_ALARM.
The B<PACT> field is TRUE while the record is being processed. For
The B<PACT> field is TRUE while the record is active (being processed). For
asynchronous records PACT can be TRUE from the time record processing is
started until the asynchronous completion occurs. As long as PACT is TRUE,
dbProcess will not call the record processing routine. See Application
Developers Guide for details on usage of PACT.
The B<FLNK> field is a database link to another record (the "target" record).
Processing a record with a specified FLNK field will force processing of the
target record, provided the target record's SCAN field is set to C<Passive>.
The B<FLNK> field is a link pointing to another record (the "target" record).
Processing a record with the FLNK field set will trigger processing of the
target record towards the end of processing the first record (but before PACT is
cleared), provided the target record's SCAN field is set to C<Passive>. If the
FLNK field is a Channel Access link it must point to the PROC field of the
target record.
The B<SPVT> field is for internal use by the scanning system.
@@ -236,35 +239,46 @@ The B<SPVT> field is for internal use by the scanning system.
=head3 Alarm Fields
These fields indicate the status and severity of alarms, or else determine the
Alarm fields indicate the status and severity of record alarms, or determine
how and when alarms are triggered. Of course, many records have alarm-related
fields not common to all records. These fields are listed and explained in the
fields not common to all records. Those fields are listed and explained in the
appropriate section on each record.
The B<STAT> field contains the current alarm status.
The B<SEVR> field contains the current alarm severity.
These two fields are seen outside database access. The B<NSTA> and B<NSEV>
fields are used by the database access, record support, and device support
routines to set new alarm status and severity values. Whenever any software
component discovers an alarm condition, it uses the following macro function:
recGblSetSevr(precord,new_status,new_severity) This ensures that the current
alarm severity is set equal to the highest outstanding alarm. The file alarm.h
defines all allowed alarm status and severity values.
The B<AMSG> string field may contain more detailed information about the alarm.
The STAT, SEVR and AMSG fields hold alarm information as seen outside of the
database. The B<NSTA>, B<NSEV> and B<NAMSG> fields are used during record
processing by the database access, record support, and device support routines
to set new alarm status and severity values and message text. Whenever any
software component discovers an alarm condition, it calls one of these routines
to register the alarm:
recGblSetSevr(precord, new_status, new_severity);
recGblSetSevrMsg(precord, new_status, new_severity, "Message", ...);
These check the current alarm severity and update the NSTA, NSEV and NAMSG
fields if appropriate so they always relate to the highest severity alarm seen
so far during record processing. The file alarm.h defines the allowed alarm
status and severity values. Towards the end of record processing these fields
are copied into the STAT, SEVR and AMSG fields and alarm monitors triggered.
The B<ACKS> field contains the highest unacknowledged alarm severity.
The B<ACKT> field specifies if it is necessary to acknowledge transient
The B<ACKT> field specifies whether it is necessary to acknowledge transient
alarms.
The B<UDF> indicates if the record's value is B<U>nB<D>eB<F>ined. Typically
this is caused by a failure in device support, the fact that the record has
never been processed, or that the VAL field currently contains a NaN (not a
number). UDF is initialized to TRUE at IOC initialization. Record and device
support routines which write to the VAL field are responsible for setting UDF.
The B<UDF> indicates if the record's value is B<U>nB<D>eB<F>ined. Typically this
is caused by a failure in device support, the fact that the record has never
been processed, or that the VAL field currently contains a NaN (not a number) or
Inf (Infinite) value. UDF defaults to TRUE but can be set in a database file.
Record and device support routines which write to the VAL field are generally
responsible for setting and clearing UDF.
=fields STAT, SEVR, NSTA, NSEV, ACKS, ACKT, UDF
=fields STAT, SEVR, AMSG, NSTA, NSEV, NAMSG, ACKS, ACKT, UDF
=cut
@@ -422,9 +436,11 @@ The B<DPVT> field is is for private use of the device support modules.
=head3 Debugging Fields
The B<TPRO> field is used for trace processing. If this field is non-zero a
message is printed whenever this record is processed, and when any other
record in the same lock-set is processed by a database link from this record.
The B<TPRO> field can be used to trace record processing. When this field is
non-zero and the record is processed, a trace message will be be printed for
this record and any other record in the same lock-set that is triggered by a
database link from this record. The trace message includes the name of the
thread doing the processing, and the name of the record being processed.
The B<BKPT> field indicates if there is a breakpoint set at this record. This
supports setting a debug breakpoint in the record processing. STEP through
@@ -435,32 +451,26 @@ database processing can be supported using this.
=head3 Miscellaneous Fields
The B<ASG> field contains a character string value defining the access
security group for this record. If left empty, the record is placed in group
DEFAULT.
The B<ASG> string field sets the name of the access security group used for this
record. If left empty, the record is placed in group C<DEFAULT>.
The B<ASP> field is a field for private use of the access security system.
The B<ASP> field is private for use by the access security system.
The B<DISP> field controls dbPutFields to this record which are normally
issued by channel access. If the field is set to TRUE all dbPutFields
directed to this record are ignored except to the field DISP itself.
The B<DISP> field controls whether puts from outside the IOC are allowed to
modify the fields of this record at all. If the field is set to TRUE all puts
directed to this record are ignored, except for puts to the field DISP itself.
The B<DTYP> field specifies the device type for the record. Each record type
has its own set of device support routines which are specified in
devSup.ASCII. If a record type does not have any associated device support,
DTYP and DSET are meaningless.
The B<DTYP> field specifies the device type for the record. Most record types
have their own set of device types which are specified in the IOC's database
definition file. If a record type does not call any device support routines,
the DTYP and DSET fields are not used.
The B<MLOK> field contains the monitor lock. The lock used by the monitor
routines when the monitor list is being used. The list is locked whenever
monitors are being scheduled, invoked, or when monitors are being added to or
removed from the list. This field is accessed only by the dbEvent routines.
The B<MLOK> field contains a mutex which is locked by the monitor routines in
dbEvent.c whenever the monitor list for this record is accessed.
The B<MLIS> field is the head of the list of monitors connected to this
The B<MLIS> field holds a linked list of client monitors connected to this
record. Each record support module is responsible for triggering monitors for
any fields that change as a result of record processing. Monitors are present
if mlis count is greater than zero. The call to trigger monitors is:
db_post_event(precord,&data,mask), where "mask" is some combination of
DBE_ALARM, DBE_VALUE, and DBE_LOG.
any fields that change as a result of record processing.
The B<PPN> field contains the address of a putNotify callback.
@@ -474,23 +484,24 @@ The B<RDES> field contains the address of dbRecordType
The B<RPRO> field specifies a reprocessing of the record when current
processing completes.
The B<TIME> field contains the time when this record was last processed in
standard format.
The B<TIME> field holds the time stamp when this record was last processed.
The B<UTAG> field can be used to hold a site-specific 64-bit User Tag value
that is associated with the record's time stamp.
The B<TSE> field indicates the mechanism to use to get the time stamp. '0' -
call get time as before '-1' - call the time stamp driver and use the best
source available. '-2' - the device support provides the time stamp from the
hardware. Values between 1-255 request the time of the last occurance of a
generalTime event.
source available. '-2' - the device support sets the time stamp and optional
user tag from the hardware. Values between 1-255 request the time of the last
occurance of a generalTime event.
The B<TSEL> field contains an input link for obtaining the time stamp. If this
link references the .TIME field of a record then the time stamp of the
referenced record becomes the time stamp for this record as well. In this
case, an internal flag is set and ".TIME" is then overwritten by ".VAL". If
any other field is referenced, the field value is read and stored in the .TSE
field which is then used to acquire a timestamp.
link points to the TIME field of a record then the time stamp and user tag of
that record are copied directly into this record (Channel Access links can only
copy the time stamp). If the link points to any other field, that field's value
is read and stored in the TSE field which is then used to acquire a time stamp.
=fields ASG, ASP, DISP, DTYP, MLOK, MLIS, PPN, PPNR, PUTF, RDES, RPRO, TIME, TSE, TSEL
=fields ASG, ASP, DISP, DTYP, MLOK, MLIS, PPN, PPNR, PUTF, RDES, RPRO, TIME, UTAG, TSE, TSEL
=cut