#*************************************************************************
# Copyright (c) 2002 The University of Chicago, as Operator of Argonne
#     National Laboratory.
# Copyright (c) 2002 The Regents of the University of California, as
#     Operator of Los Alamos National Laboratory.
# EPICS BASE is distributed subject to a Software License Agreement found
# in file LICENSE that is included with this distribution.
#*************************************************************************

=title Array Input (aai)

The array input record type is used to read array data. The array data can
contain any of the supported data types. The record is in many ways similar to the
waveform record. It allows, however, the device support to allocate the array
storage.

=recordtype aai

=cut

menu(aaiPOST) {
	choice(aaiPOST_Always,"Always")
	choice(aaiPOST_OnChange,"On Change")
}

recordtype(aai) {

=head2 Parameter Fields

The record-specific fields are described below, grouped by functionality.

=head3 Scan Parameters

The array input record has the standard fields for specifying under what
circumstances the record will be processed.
These fields are described in L<Scan Fields|dbCommonRecord/Scan Fields>.

=head3 Read Parameters

These fields are configurable by the user to specify how and from where the record
reads its data. The INP field determines from where the array input gets
its input. It can be a hardware address, a channel access or database link, or a
constant. Only in records that use soft device support can the INP field be a
channel access link, a database link, or a constant. Otherwise, the INP field must
be a hardware address.

=head4 Fields related to waveform reading

The DTYP field must contain the name of the appropriate device support module.
The values retrieved from the input link are placed in an array referenced by
VAL. (If the INP link is a constant, elements can be placed in the array via
dbPuts.) NELM specifies the number of elements that the array will hold, while
FTVL specifies the data type of the elements (follow the link in the table below
for a list of the available choices).

=fields DTYP, INP, NELM, FTVL

=head3 Operator Display Parameters

These parameters are used to present meaningful data to the operator. They
display the value and other parameters of the waveform either textually or
graphically.

=head4 Fields related to I<Operator Display>

EGU is a string of up to 16 characters describing the units that the array data
measures. It is retrieved by the C<<< get_units() >>> record support routine.

The HOPR and LOPR fields set the upper and lower display limits for array
elements referenced by the VAL field. Both the C<<< get_graphic_double() >>> and
C<<< get_control_double() >>> record support routines retrieve these fields.

The PREC field determines the floating point precision with which to display the
array values. It is used whenever the C<<< get_precision() >>> record support
routine is called.

See L<Fields Common to All Record Types|dbCommonRecord/Operator Display
Parameters> for more on the record name (NAME) and description (DESC) fields.


=fields EGU, HOPR, LOPR, PREC, NAME, DESC


=head3 Alarm Parameters

The array input record has the alarm parameters common to all record types.

=head3 Monitor Parameters

These parameters are used to determine when to send monitors placed on the VAL
field. The APST and MPST fields are a menu with choices C<Always> and C<On
Change>. The default is C<Always>, thus monitors will normally be sent every time
the record processes. Selecting C<On Change> causes a 32-bit hash of the VAL
field buffer to be calculated and compared with the previous hash value every
time the record processes; the monitor will only be sent if the hash is
different, indicating that the buffer has changed. Note that there is a small
chance that two different value buffers might result in the same hash value, so
for critical systems C<Always> may be a better choice, even though it re-sends
duplicate data.

=fields APST, MPST, HASH

=head4 Menu aaiPOST

These are the possible choices for the C<APST> and C<MPST> fields:

=menu aaiPOST

=head3 Run-time Parameters

These parameters are used by the run-time code for processing the array
input record. They are not configured using a configuration tool. Only the VAL
field is modifiable at run-time.

VAL references the array where the array input record stores its data. The
BPTR field holds the address of the array.

The NORD field holds a counter of the number of elements that have been read
into the array.

=fields VAL, BPTR, NORD

=head3 Simulation Mode Parameters

The following fields are used to operate the record in simulation mode.

If SIMM (fetched through SIML) is YES, the record is put in SIMS
severity and the value is fetched through SIOL.
SSCN sets a different SCAN mechanism to use in simulation mode.
SDLY sets a delay (in sec) that is used for asynchronous simulation
processing.

See L<Input Simulation Fields|dbCommonInput/Input Simulation Fields>
for more information on simulation mode and its fields.

=fields SIML, SIMM, SIOL, SIMS, SDLY, SSCN

=begin html

<br>
<hr>
<br>

=end html

=head2 Record Support

=head3 Record Support Routines

=head4 init_record

   static long init_record(aaiRecord *prec, int pass)

If device support includes an C<init_record()> routine it is called, but unlike
most record types this occurs in pass 0, which allows the device support to
allocate the array buffer itself.

Since EPICS 7.0.5 the device support may return C<AAI_DEVINIT_PASS1> to request
a second call to its C<init_record()> routine in pass 1.

Checks if device support allocated array space. If not, space for the array is
allocated using NELM and FTVL. The array address is stored in BPTR.

This routine initializes SIMM with the value of SIML if SIML type is CONSTANT
link or creates a channel access link if SIML type is PV_LINK. VAL is likewise
initialized if SIOL is CONSTANT or PV_LINK.

This routine next checks to see that device support is available and a device
support read routine is defined. If either does not exist, an error message is
issued and processing is terminated

=head4 process

  static long process(aaiRecord *prec)

See L</"Record Processing"> section below.

=head4 cvt_dbaddr

  static long cvt_dbaddr(DBADDR *paddr)

This is called by dbNameToAddr. It makes the dbAddr structure refer to the
actual buffer holding the result.

=head4 get_array_info

  static long get_array_info(DBADDR *paddr, long *no_elements, long *offset)

Obtains values from the array referenced by VAL.

=head4 put_array_info

  static long put_array_info(DBADDR *paddr, long nNew)

Writes values into the array referenced by VAL.

=head4 get_units

  static long get_units(DBADDR *paddr, char *units)

Retrieves EGU.

=head4 get_prec

  static long get_precision(DBADDR *paddr, long *precision)

Retrieves PREC if field is VAL field. Otherwise, calls C<<< recGblGetPrec() >>>.

=head4 get_graphic_double

  static long get_graphic_double(DBADDR *paddr, struct dbr_grDouble *pgd)

Sets the upper display and lower display limits for a field. If the field is VAL
the limits are set to HOPR and LOPR, else if the field has upper and lower
limits defined they will be used, else the upper and lower maximum values for
the field type will be used.

Sets the following values:

  upper_disp_limit = HOPR
  lower_disp_limit = LOPR

=head4 get_control_double

  static long get_control_double(DBADDR *paddr, struct dbr_ctrlDouble *pcd)

Sets the upper control and the lower control limits for a field. If the field is
VAL the limits are set to HOPR and LOPR, else if the field has upper and lower
limits defined they will be used, else the upper and lower maximum values for
the field type will be used.

Sets the following values

  upper_ctrl_limit = HOPR
  lower_ctrl_limit = LOPR

=head3 Record Processing

Routine process implements the following algorithm:

=over

=item 1.

Check to see that the appropriate device support module exists. If it doesn't,
an error message is issued and processing is terminated with the PACT field
still set to TRUE. This ensures that processes will no longer be called for this
record. Thus error storms will not occur.

=item 2.

Call device support read routine C<read_aai()>.

=item 3.

If PACT has been changed to TRUE, the device support read routine has started
but has not completed writing the new value. In this case, the processing
routine merely returns, leaving PACT TRUE.

=item 4.

Check to see if monitors should be invoked.

=over

=item *

Alarm monitors are invoked if the alarm status or severity has changed.

=item *

Archive and value change monitors are invoked if APST or MPST are Always or if
the result of the hash calculation is different.

=item *

NSEV and NSTA are reset to 0.

=back

=item 5.

Scan forward link if necessary, set PACT FALSE, and return.

=back

=begin html

<br>
<hr>
<br>

=end html

=cut

	include "dbCommon.dbd"
    %
    %/* Declare Device Support Entry Table */
    %struct aaiRecord;
    %typedef struct aaidset {
    %    dset common; /*init_record returns: (-1,0,AAI_DEVINIT_PASS1)=>(failure,success,callback)*/
    %    long (*read_aai)(struct aaiRecord *prec); /*returns: (-1,0)=>(failure,success)*/
    %} aaidset;
    %#define HAS_aaidset
	%#define AAI_DEVINIT_PASS1 2
    %
	field(VAL,DBF_NOACCESS) {
		prompt("Value")
		asl(ASL0)
		special(SPC_DBADDR)
		pp(TRUE)
		extra("void *		val")
		#=type Set by FTVL[NELM]
		#=read Yes
		#=write Yes
	}
	field(PREC,DBF_SHORT) {
		prompt("Display Precision")
		promptgroup("80 - Display")
		interest(1)
		prop(YES)		# get_precision
	}
	field(INP,DBF_INLINK) {
		prompt("Input Specification")
		promptgroup("40 - Input")
		interest(1)
	}
	field(EGU,DBF_STRING) {
		prompt("Engineering Units")
		promptgroup("80 - Display")
		interest(1)
		size(16)
		prop(YES)		# get_units
	}
	field(HOPR,DBF_DOUBLE) {
		prompt("High Operating Range")
		promptgroup("80 - Display")
		interest(1)
		prop(YES)		# get_graphic_double, get_control_double
	}
	field(LOPR,DBF_DOUBLE) {
		prompt("Low Operating Range")
		promptgroup("80 - Display")
		interest(1)
		prop(YES)		# get_graphic_double, get_control_double
	}
	field(NELM,DBF_ULONG) {
		prompt("Number of Elements")
		promptgroup("30 - Action")
		special(SPC_NOMOD)
		interest(1)
		initial("1")
		prop(YES)		# get_graphic_double, get_control_double
	}
	field(FTVL,DBF_MENU) {
		prompt("Field Type of Value")
		promptgroup("30 - Action")
		special(SPC_NOMOD)
		interest(1)
		menu(menuFtype)
	}
	field(NORD,DBF_ULONG) {
		prompt("Number elements read")
		special(SPC_NOMOD)
	}
	field(BPTR,DBF_NOACCESS) {
		prompt("Buffer Pointer")
		special(SPC_NOMOD)
		interest(4)
		extra("void *		bptr")
	}
    field(SIML,DBF_INLINK) {
        prompt("Simulation Mode Link")
        promptgroup("90 - Simulate")
        interest(1)
    }
    field(SIMM,DBF_MENU) {
        prompt("Simulation Mode")
        special(SPC_MOD)
        interest(1)
        menu(menuYesNo)
    }
    field(SIMS,DBF_MENU) {
        prompt("Simulation Mode Severity")
        promptgroup("90 - Simulate")
        interest(2)
        menu(menuAlarmSevr)
    }
    field(SIOL,DBF_INLINK) {
        prompt("Simulation Input Link")
        promptgroup("90 - Simulate")
        interest(1)
    }
    field(OLDSIMM,DBF_MENU) {
        prompt("Prev. Simulation Mode")
        special(SPC_NOMOD)
        interest(4)
        menu(menuSimm)
    }
    field(SSCN,DBF_MENU) {
        prompt("Sim. Mode Scan")
        promptgroup("90 - Simulate")
        interest(1)
        menu(menuScan)
        initial("65535")
    }
    field(SDLY,DBF_DOUBLE) {
        prompt("Sim. Mode Async Delay")
        promptgroup("90 - Simulate")
        interest(2)
        initial("-1.0")
    }
    %#include "callback.h"
    field(SIMPVT,DBF_NOACCESS) {
        prompt("Sim. Mode Private")
        special(SPC_NOMOD)
        interest(4)
        extra("epicsCallback            *simpvt")
    }
    field(MPST,DBF_MENU) {
		prompt("Post Value Monitors")
		promptgroup("80 - Display")
		interest(1)
		menu(aaiPOST)
	}
	field(APST,DBF_MENU) {
		prompt("Post Archive Monitors")
		promptgroup("80 - Display")
		interest(1)
		menu(aaiPOST)
	}
	field(HASH,DBF_ULONG) {
		prompt("Hash of OnChange data.")
		interest(3)
	}

=head2 Device Support

=head3 Fields Of Interest To Device Support

Each array input record record must have an associated set of device
support routines. The primary responsibility of the device support routines is to
obtain a new array value whenever C<read_aai()> is called. The device support
routines are primarily interested in the following fields:

=fields PACT, DPVT, NSEV, NSTA, INP, NELM, FTVL, BPTR, NORD

=head3 Device Support Routines

Device support consists of the following routines:

=head4 report

  long report(int level)

This optional routine is called by the IOC command C<dbior> and is passed the
report level that was requested by the user.
It should print a report on the state of the device support to stdout.
The C<level> parameter may be used to output increasingly more detailed
information at higher levels, or to select different types of information with
different levels.
Level zero should print no more than a small summary.

=head4 init

  long init(int after)

This optional routine is called twice at IOC initialization time.
The first call happens before any of the C<init_record()> calls are made, with
the integer parameter C<after> set to 0.
The second call happens after all of the C<init_record()> calls have been made,
with C<after> set to 1.

=head4 init_record

  long init_record(dbCommon *precord)

This routine is optional.
If provided, it is called by the record support's C<init_record()> routine in
pass 0.
The device support may allocate memory for the VAL field's array (enough space
for NELM elements of type FTVA) from its own memory pool if desired, and store
the pointer to this buffer in the BPTR field.
The record will use C<calloc()> for this memory allocation if BPTR has not been
set by this routine.
The routine must return 0 for success, -1 or a error status on failure.

Since EPICS 7.0.5 if this routine returns C<AAI_DEVINIT_PASS1> in pass 0, it
will be called again in pass 1 with the PACT field set to C<AAI_DEVINIT_PASS1>.
In pass 0 the PACT field is set to zero (FALSE).

=head4 get_ioint_info

  long get_ioint_info(int cmd, dbCommon *precord, IOSCANPVT *ppvt)

This routine is called by the ioEventScan system each time the record is added
or deleted from an I/O event scan list.  C<cmd> has the value (0,1) if the
record is being (added to, deleted from) an I/O event list. It must be
provided for any device type that can use the ioEvent scanner.

=head4 read_aai

  long read_aai(dbCommon *precord)

This routine should provide a new input value.
It returns the following values:

=over

=item *

0: Success.

=item *

Other: Error.

=back

=head3 Device Support For Soft Records

The C<<< Soft Channel >>> device support is provided to read values from other
records via the INP link, or to hold array values that are written into it.

If INP is a constant link the array value gets loaded from the link constant by
the C<record_init()> routine, which also sets NORD.
The C<read_aai()> routine does nothing in this case.

If INP is a database or channel access link, the C<read_aai()> routine gets a
new array value from the link and sets NORD.

=cut
}
