Multi-Bit Binary Output Direct Record (mbboDirect)

The mbboDirect record performs the opposite function to that of the mbbiDirect record. It accumulates bits (in the fields B0 - BF) as unsigned characters, and converts them to a word which is then written out to hardware. If a bit field is non-zero, it is interpreted as a binary 1. On the other hand, if it is zero, it is interpreted as a binary 0.

Parameter Fields

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

Scan Parameters

The mbboDirect record has the standard fields for specifying under what circumstances it will be processed. These fields are listed in "Scan Fields". In addition, "Scanning Specification" explains how these fields are used. Note that I/O event scanning is only supported for those card types that interrupt.

Desired Output Parameters

The mbboDirect record, like all output records, must specify where its output originates. The output mode select field (OMSL) determines whether the output originates from another record or from database access. When set to closed_loop, the desired output is retrieved from the link specified in the desired output (DOL) field--which can specify either a database or channel access link--and placed into the VAL field. When set to supervisory, the DOL field is ignored and the current value of VAL is used. The desired output can be written into the VAL field via dpPuts at run-time when the record is in supervisory mode. DOL can also be a constant, in which case VAL is initialized to the constant value. Note that OMSL cannot be closed_loop when DOL is a constant. See "Address Specification" for information on how to specify database links.

VAL is then converted to RVAL in the routine described in the next section. However, the Soft Channel device support module for the mbboDirect record writes the VAL field's value without any conversion.

Field	Summary	Type	DCT	Default	Read	Write	CA PP
OMSL	Output Mode Select	MENU (menuOmsl)	Yes		Yes	Yes	Yes
DOL	Desired Output Loc	INLINK	Yes		Yes	Yes	No
VAL	Word	USHORT	Yes		Yes	Yes	Yes

Convert and Write Parameters

For records that are to write values to hardware devices, the OUT output link must contain the address of the I/O card, and the DTYP field must specify the proper device support module. Be aware that the address format differs according to the I/O bus used. See "Address Specification" for information on the format of hardware addresses.

If the mbboDirect record does not use the Soft Channel device support module, then VAL is converted to RVAL, and RVAL is the actual 16-bit word sent out. RVAL is set equal to VAL and then shifted left by the number of bits specified in the SHFT field (the SHFT value is set by device support and is not configurable by the user). RVAL is then sent out to the location specified in the OUT field.

For mbboDirect records that specify a database link, a channel access link, or a constant, the DTYP field must specify either one of two soft device support routines--{Soft Channel} or Raw Soft Channel. The difference between the two is that Soft Channel writes the desired output value from VAL directly to the output link while Raw Soft Channel writes the value from RVAL to the output link after it has undergone the conversion described above. See "Address Specification" for information on how to specify database links.

Field	Summary	Type	DCT	Default	Read	Write	CA PP
OUT	Output Specification	OUTLINK	Yes		Yes	Yes	No
RVAL	Raw Value	ULONG	No		Yes	No	Yes
SHFT	Shift	ULONG	Yes		Yes	Yes	No
B0	Bit 0	UCHAR	Yes		Yes	Yes	Yes
B1	Bit 1	UCHAR	Yes		Yes	Yes	Yes
B2	Bit 2	UCHAR	Yes		Yes	Yes	Yes
B3	Bit 3	UCHAR	Yes		Yes	Yes	Yes
B4	Bit 4	UCHAR	Yes		Yes	Yes	Yes
B5	Bit 5	UCHAR	Yes		Yes	Yes	Yes
B6	Bit 6	UCHAR	Yes		Yes	Yes	Yes
B7	Bit 7	UCHAR	Yes		Yes	Yes	Yes
B8	Bit 8	UCHAR	Yes		Yes	Yes	Yes
B9	Bit 9	UCHAR	Yes		Yes	Yes	Yes
BA	Bit 10	UCHAR	Yes		Yes	Yes	Yes
BB	Bit 11	UCHAR	Yes		Yes	Yes	Yes
BC	Bit 12	UCHAR	Yes		Yes	Yes	Yes
BD	Bit 13	UCHAR	Yes		Yes	Yes	Yes
BE	Bit 14	UCHAR	Yes		Yes	Yes	Yes
BF	Bit 15	UCHAR	Yes		Yes	Yes	Yes

Operator Display Parameters

See "Fields Common to All Record Types" for more on the record name (NAME) and description (DESC) fields.

Field	Summary	Type	DCT	Default	Read	Write	CA PP
NAME	Record Name	STRING [61]	No		Yes	No	No
DESC	Descriptor	STRING [41]	Yes		Yes	Yes	No

Alarm Parameters

The possible alarm conditions for mbboDirect records are the SCAN, READ, and INVALID alarms. The SCAN and READ alarms are not configurable by the user since they are always of MAJOR severity. See "Alarm Specification" for a complete explanation of Scan and Read alarms.

The IVOA field specifies an action to take when the INVALID alarm is triggered. There are three possible actions: Continue normally, Don't drive outputs, or Set output to IVOV. When Set output to IVOV is specified and a INVALID alarm is triggered, the record will write the value in the IVOV field to output. See "Invalid Alarm Output Action" for more information. "Alarm Fields" lists other fields related to a alarms that are common to all record types.

Field	Summary	Type	DCT	Default	Read	Write	CA PP
IVOA	INVALID outpt action	MENU (menuIvoa)	Yes		Yes	Yes	No
IVOV	INVALID output value	USHORT	Yes		Yes	Yes	No

Run-time and Simulation Mode Parameters

These parameters are used by the run-time code for processing the mbbo Direct record.

MASK is used by device support routine to read the hardware register. Record support sets low order NOBT bits. Device support can shift this value.

MLST holds the value when the last monitor for value change was triggered.

Field	Summary	Type	DCT	Default	Read	Write	CA PP
NOBT	Number of Bits	SHORT	Yes		Yes	No	No
ORAW	Prev Raw Value	ULONG	No		Yes	No	No
MASK	Hardware Mask	ULONG	No		Yes	No	No
MLST	Last Value Monitored	ULONG	No		Yes	No	No

The following fields are used to operate the mbboDirect record in the simulation mode. See "Simulation Mode" for more information on the simulation mode fields.

Field	Summary	Type	DCT	Default	Read	Write	CA PP
SIOL	Sim Output Specifctn	OUTLINK	Yes		Yes	Yes	No
SIML	Sim Mode Location	INLINK	Yes		Yes	Yes	No
SIMM	Simulation Mode	MENU (menuYesNo)	No		Yes	Yes	No
SIMS	Sim mode Alarm Svrty	MENU (menuAlarmSevr)	Yes		Yes	Yes	No

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Record Support

Record Support Routines

init_record

This routine initializes SIMM if SIML is a constant or creates a channel access link if SIML is PV_LINK. If SIOL is PV_LINK a channel access link is created.

This routine next checks to see that device support is available.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 DOL is a constant, then VAL is initialized to its value and UDF is set to FALSE.

MASK is cleared and then the NOBT low order bits are set.

If device support includes init_record(), it is called.

If device support returns success, VAL is then set from RVAL and UDF is set to FALSE.

Process

See next section.

Record Processing

Routine process implements the following algorithm:

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.
2. If PACT is FALSE
   • If DOL is DB_LINK and OMSL is CLOSED_LOOP
     • Get value from DOL
     • Set PACT to FALSE
3. Convert
   • If PACT is FALSE, compute RVAL
     • Set RVAL = VAL
     • Shift RVAL left SHFT bits
   • Status=write_mbboDirect
4. If PACT has been changed to TRUE, the device support write output routine has started but has not completed writing the new value. In this case, the processing routine merely returns, leaving PACT TRUE.
5. Check to see if monitors should be invoked.
   • Alarm monitors are invoked if the alarm status or severity has changed.
   • Archive and value change monitors are invoked if MLST is not equal to VAL.
   • Monitors for RVAL and RBV are checked whenever other monitors are invoked.
   • NSEV and NSTA are reset to 0.
6. Scan forward link if necessary, set PACT FALSE, and return.

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Device Support

Fields Of Interest To Device Support

Each mbboDirect record must have an associated set of device support routines. The primary responsibility of the device support routines is to obtain a new raw mbbo value whenever write_mbboDirect is called. The device support routines are primarily interested in the following fields:

Field	Summary	Type	DCT	Default	Read	Write	CA PP
PACT	Record active	UCHAR	No		Yes	No	No
DPVT	Device Private	NOACCESS	No		No	No	No
UDF	Undefined	UCHAR	Yes	1	Yes	Yes	Yes
NSEV	New Alarm Severity	MENU (menuAlarmSevr)	No		Yes	No	No
NSTA	New Alarm Status	MENU (menuAlarmStat)	No		Yes	No	No
NOBT	Number of Bits	SHORT	Yes		Yes	No	No
OUT	Output Specification	OUTLINK	Yes		Yes	Yes	No
RVAL	Raw Value	ULONG	No		Yes	No	Yes
RBV	Readback Value	ULONG	No		Yes	No	No
MASK	Hardware Mask	ULONG	No		Yes	No	No
SHFT	Shift	ULONG	Yes		Yes	Yes	No

Device Support Routines

Device support consists of the following routines:

long report(int level)

This optional routine is called by the IOC command 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 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.

long init(int after)

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

init_record

  init_record(precord)

This routine is optional. If provided, it is called by the record support init_record() routine. If MASK is used, it should be shifted if necessary and SHFT given a value.

get_ioint_info

  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_mbboDirect

  write_mbboDirect(precord)

This routine must output a new value. It returns the following values:

• 0: Success.
• Other: Error.

Device Support For Soft Records

This SOft Channel module writes the current value of VAL.

If the OUT link type is PV_LINK, then dbCaAddInlink is called by init_record().

write_mbboDirect calls recGblPutLinkValue to write the current value of VAL.

See Soft Output.