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Field Type DCT Initial Access Modify Rec Proc PP
Monitor
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VAL DOUBLE No 0 Yes Yes Yes Yes
OVAL DOUBLE No 0 Yes Yes Yes No
OUT OUTLINK Yes 0 No No N/A No
OROC FLOAT Yes 0 Yes Yes No No
DOL INLINK Yes 0 No No N/A No
OMSL GBLCHOICE Yes 0 Yes Yes No No
OIF RECCHOICE Yes 0 Yes Yes No No
PREC SHORT Yes 0 Yes Yes No No
LINR CVTCHOICE Yes 0 Yes Yes No Yes
EGUF FLOAT Yes 0 Yes Yes No Yes
EGUL FLOAT Yes 0 Yes Yes No Yes
EGU STRING Yes null Yes Yes No No
ESLO DOUBLE No 1 Yes No No No
ROFF LONG No 0 Yes Yes No Yes
DRVH FLOAT Yes 0 Yes Yes No Yes
DRVL FLOAT Yes 0 Yes Yes No Yes
HOPR FLOAT Yes 0 Yes Yes No No
LOPR FLOAT Yes 0 Yes Yes No No
AOFF FLOAT Yes 0 Yes Yes No Yes
ASLO FLOAT Yes 0 Yes Yes No Yes
HIHI FLOAT Yes 0 Yes Yes No Yes
LOLO FLOAT Yes 0 Yes Yes No Yes
HIGH FLOAT Yes 0 Yes Yes No Yes
LOW FLOAT Yes 0 Yes Yes No Yes
HHSV GBLCHOICE Yes 0 Yes Yes No Yes
LLSV GBLCHOICE Yes 0 Yes Yes No Yes
HSV GBLCHOICE Yes 0 Yes Yes No Yes
LSV GBLCHOICE Yes 0 Yes Yes No Yes
HYST DOUBLE Yes 0 Yes Yes No No
ADEL DOUBLE Yes 0 Yes Yes No No
MDEL DOUBLE Yes 0 Yes Yes No No
RVAL LONG No 0 Yes Yes Yes Yes
ORAW LONG No 0 Yes No No No
RBV LONG No 0 Yes No Yes No
ORBV LONG No 0 Yes No No No
PVAL DOUBLE No 0 Yes No No No
LALM DOUBLE No 0 Yes No No No
ALST DOUBLE No 0 Yes No No No
MLST DOUBLE No 0 Yes No No No
PBRK NOACCESS No 4 No No No
INIT SHORT No 0 Yes No No No
LBRK SHORT No 0 Yes No No No
SIOL OUTLINK Yes 0 No No N/A No
SIML INLINK Yes 0 No No N/A No
SIMM GBLCHOICE No 0 Yes Yes No No
SIMS GBLCHOICE Yes 0 Yes Yes No No
IVOA GBLCHOICE Yes 0 Yes Yes No No
IVOV DOUBLE Yes 0 Yes Yes No No
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Name Summary Description
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VAL Value This is the desired output value, in engineering units. If
DRVH and DRVL are defined, VAL is forced to be within
the drive limits. VAL is either obtained from DOL or set
via dbPuts.
OVAL Output Value This is the desired output value, after adjustments, in
engineering units. It is just VAL possibly adjusted by
OROC. This is the value used to compute RVAL. OVAL is
used to enforce a maximum rate of change limit before
converting the desired value to a raw value. If soft device
support is selected and OUT is a database or channel
access link, this is the value written to the link.
OUT Output Link This field is used by the device support routines to decide
where to send output. For soft records, it can be a
constant, a database link, or a channel access link. If the
link is a constant, the result is no output.
OROC Maximum Output If this is not zero, it specifies the maximum change in
Rate of Change value (engineering units) to be sent to OUT each time the
record is processed. It is this field that can cause VAL and
OVAL to differ.
DOL Desired Output If DOL is a database or channel access link and OMSL is
Location (an Input CLOSED_LOOP, then VAL is read from DOL. After the
Link) check for drive limits, VAL will be set to the value
determined by DOL.
OMSL Output Mode Select This field has either the value SUPERVISORY or
CLOSED_LOOP. DOL is used to determine VAL only if
OMSL has the value CLOSED_LOOP. By setting this field
the record can be switched between supervisory and
closed loop mode of operation. While in closed loop
mode, the VAL field cannot be set via dbPuts.
OIF Out Full or This field is used when input is obtained from DOL, and
Incremental determines if the value obtained from DOL is an increment
to add to the current VAL or is the actual VAL desired.
PREC Display Precision Precision with which to display VAL. This field is used by
record support to supply a value when get_precision
is called.
LINR Conversion Type No conversion, linear and breakpoint table conversion are
supported.
EGUF Engineering Units These fields are used to perform linear conversions. It is
Full the responsibility of the device support routines to use
EGUF and EGUL to compute ESLO and ROFF. EGUF and
EGUL must be set by the user to the engineering units
corresponding to the high and low ADC limits. For
example if the DAC has a range of -10 to +10 Volts, then
EGUF must be the engineering units value corresponding
to 10 volts and EGUL to -10 volts. If a linear conversion is
specified ESLO, ROFF, and EGUL are used to convert the
value from/to engineering units using the following
formula:
RVAL = (OVAL - EGUL)/ESLO - ROFF
EGUL Engineering Units
Low
ESLO Slope For Linear
Conversions
ROFF Raw Value Offset
EGU Engineering Units ASCII string describing Engineering units. This field is
used by record support to supply a units description string
when get_units is called.
DRVH Drive High If these values are defined then VAL will forced to be in
the range:
DRVL<=VAL<=DRVH
DRVL Drive Low
HOPR High Operating These fields determine the upper and lower display limits
Range for graphics displays and the upper and lower control
limits for control displays. The fields are used by record
support to honor calls to get_graphic_double or
get_control_double. If these values are defined,
they must be in the range:
DRVL<=LOPR<=HOPR<=DRVH.
LOPR Low Operating
Range
AOFF Adjustment Offset These fields are adjustment parameters for the raw output
values. They are applied to the raw output value after
conversion from engineering units.
ASLO Adjustment Slope
HIHI Hihi Alarm Limit These fields specify the alarm limits and severities.
HIGH High Alarm Limit
LOW Low Alarm Limit
LOLO Lolo Alarm Limit
HHSV Hihi Alarm Severity
HSV High Alarm Severity
LSV Low Alarm Severity
LLSV Lolo Alarm Severity
HYST Alarm Deadband These parameters specify hysteresis factors for triggering
monitor callbacks, i.e. callbacks specified by calls to
caAddEvent or dbAddEvent. A monitor will not be
triggered until VAL changes by more than the specified
amount.
ADEL Archive Deadband
MDEL Monitor, i.e. value
change, Deadband
RVAL Raw Data Value RVAL is the value actually sent to the device.
ORAW Old raw data value ORAW is used to decide if monitors should be triggered for
RVAL.
RBV Read Back Value This is the actual read back value obtained from the
hardware itself or from the associated device driver. It is
the responsibility of the device support routine to give this
field a value.
ORBV Old read back value ORBV is used to decide if monitors should be triggered for
RBV at the same time monitors are triggered for changes
in VAL.
PVAL Previous Data
Value
LALM Last Alarm Monitor These fields are used to implement the hysteresis factors
Trigger Value for monitors.
ALST Last Archiver
Monitor Trigger
Value
MLST Last Value Change
Monitor Trigger
Value
INIT Initialize This field is used by record support to perform
initialization for LBRK and for smoothing.
LBRK Last Breakpoint Index of last breakpoint interval
PBRK Breakpoint Pointer Address of breakpoint table
SIMM Simulation Mode Simulation mode process variables. Refer to Chapter 3,
Section "Simulation Mode" on page 13 for more
information.
SIML Simulation Mode
Location
SIOL Simulation Value
Location
SIMS Simulation Mode
Alarm Severity
IVOA Invalid Alarm Whenever the record is put into INVALID alarm severity
Output Action IVOA specifies an action. See Chapter 3, Section "Invalid
Alarm Output Action" on page 14 for more information.
IVOV Invalid Alarm
Output Value
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This routine next checks to see that device support is available. If DOL is a constant, then VAL is initialized with its value and UDF is set to FALSE.
The routine next checks to see if the device support write routine is defined. If either device support or the device support write routine does not exist, an error message is issued and processing is terminated.
If device support includes init_record, it is called.
INIT is set TRUE. This causes PBRK, LBRK, and smoothing to be reinitialized
If linear conversion is requested, then VAL is computed from RVAL using the algorithm:
VAL=(RVAL+ROFF)/ESLO+EGULand UDF is set to FALSE.
For breakpoint conversion, a call is made to cvtEngToRawBpt and UDF is then set to FALSE. PVAL is set to VAL.
If the device support routine special_linconv exists it is called.
INIT is set TRUE. This causes PBRK, LBRK, and smoothing to be reinitialized.
upper_alarm_limit = HIHI upper_warning_limit = HIGH lower_warning_limit = LOW lower_alarm_limit = LOLO
RVAL = (OVAL-EGUL)/ESLO -ROFF
------------------------------------------------------------------------------------------ Name Summary Description ------------------------------------------------------------------------------------------ PACT Processing Active See Chapter 2, Section "Database Common: Field Descriptions" on page 4 for descriptions. DPVT Device Private NSEV New Alarm Severity NSTA New Alarm Status OUT Output Link This field is used by the device support routines to locate its output. EGUF Engineering Units Full These fields are used to calculate ESLO. Note that these fields correspond to the high and low hardware limits. EGUL Engineering Unit Low ESLO Slope These fields are used for linear conversions from raw to engineering units. The device support routines must calculate these fields unless they obtain values already in engineering units. ROFF Raw Offset RVAL Raw Value This is the value to write OUT. ------------------------------------------------------------------------------------------
init()This routine is called once during IOC initialization.
init_record(precord)This routine is optional. If provided, it is called by the record support init_record routine. It returns a zero for success or a 2 for success, don't convert.
get_ioint_info(int cmd,struct 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. 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.
write_ao(precord)This routine must output a new value. Asynchronous device support routines will return with PACT set to TRUE. If PACT is TRUE, the process routine will just return and not continue processing. When the asynchronous routine completes, it can call process which will again call write_ao. When finished, write_ao should set PACT to FALSE and return one the following values:
special_linconv(precord,after)This routine is called whenever either of the fields LINR, EGUF, EGUL or ROFF is modified.
If the OUT link type is PV_LINK, then dbCaAddInlink is called by init_record. init_record always returns a value of 2, which means that no conversion will ever be attempted.
write_ao calls recGblPutLinkValue to write the current value of VAL. See Chapter 3, Section "Soft Output" on page 13 for details.
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