# 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.

### 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.

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 | LONG | 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.

> 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 | USHORT | 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

### Run-time 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 | LONG | No |  | Yes | No | No

### 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 written through SIOL, without conversion. 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 Output Simulation Fields for more information on simulation mode and its fields.

> Field | Summary | Type | DCT | Default | Read | Write | CA PP
> --- | --- | --- | --- | --- | --- | --- | ---
> SIML | Simulation Mode Link | INLINK | Yes |  | Yes | Yes | No
> SIMM | Simulation Mode | MENU (menuYesNo) | No |  | Yes | Yes | No
> SIOL | Simulation Output Link | OUTLINK | Yes |  | Yes | Yes | No
> SIMS | Simulation Mode Severity | MENU (menuAlarmSevr) | Yes |  | Yes | Yes | No
> SDLY | Sim. Mode Async Delay | DOUBLE | Yes | -1.0 | Yes | Yes | No
> SSCN | Sim. Mode Scan | MENU (menuScan) | Yes | 65535 | 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 Output Action Fields for more information. Alarm Fields lists the fields related to 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 | LONG | Yes |  | Yes | Yes | No

## 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.

## 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 | USHORT | 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.