The mbbiDirect record retrieves a sixteen-bit hardware value and converts it to an array of sixteen unsigned characters, each representing a bit of the word. These fields (B0-B9, BA-BF) are set to 1 if a bit is set, and 0 if not.
This record's operation is similar to that of the multi-bit binary input record, and it has many fields in common with it. This record also has two available soft device support modules: Soft Channel and Raw Soft Channel.
The record-specific fields are described below, grouped by functionality.
The mbbiDirect record has the standard fields for specifying under what circumstances the record 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.
The device support routines obtain the record's input from the device or link specified in the INP field. For records that obtain their input from devices, the INP field 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.
Two soft device support modules can be specified in DTYP Soft Channel and Raw Soft Channel.
Raw Soft Channel reads the value into RVAL, upon which the normal conversion process is undergone. Soft Channel reads any unsigned integer directly into VAL. For a soft mbbiDirect record, the INP field can be a constant, a database, or a channel access link. If INP is a constant, then the VAL is initialized to the INP value but can be changed at run-time via dbPutField or dbPutLink. See "Address Specification" for information on how to database links.
For records that don't use Soft Channel device support, RVAL is used to determine VAL as follows:
Each of the fields, B0-BF, represents one bit of the word.
Field Summary Type DCT Default Read Write CA PP VAL Current Value USHORT Yes Yes Yes Yes INP Input Specification INLINK Yes Yes Yes No RVAL Raw Value ULONG No Yes Yes Yes SHFT Shift USHORT Yes Yes Yes No B0 Bit 0 UCHAR No Yes Yes Yes B1 Bit 1 UCHAR No Yes Yes Yes B2 Bit 2 UCHAR No Yes Yes Yes B3 Bit 3 UCHAR No Yes Yes Yes B4 Bit 4 UCHAR No Yes Yes Yes B5 Bit 5 UCHAR No Yes Yes Yes B6 Bit 6 UCHAR No Yes Yes Yes B7 Bit 7 UCHAR No Yes Yes Yes B8 Bit 8 UCHAR No Yes Yes Yes B9 Bit 9 UCHAR No Yes Yes Yes BA Bit A UCHAR No Yes Yes Yes BB Bit B UCHAR No Yes Yes Yes BC Bit C UCHAR No Yes Yes Yes BD Bit D UCHAR No Yes Yes Yes BE Bit E UCHAR No Yes Yes Yes BF Bit F UCHAR No Yes Yes Yes
These parameters are used to present meaningful data to the operator.
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
These parameters are used by the run-time code for processing the mbbi direct record. They are not configurable prior to run-time.
MASK is used by device support routine to read hardware register. Record support sets low order NOBT bits in MASK. 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 USHORT No Yes No No
The following fields are used to operate the mbbiDirect record in the simulation mode. See "Fields Common to Many Record Types" for more information on these fields.
Field Summary Type DCT Default Read Write CA PP SIOL Sim Input Specifctn INLINK Yes Yes Yes No SVAL Simulation Value ULONG No Yes Yes No SIML Sim Mode Location INLINK Yes Yes Yes No SIMM Simulation Mode MENU (menuSimm) No Yes Yes No SIMS Sim mode Alarm Svrty MENU (menuAlarmSevr) Yes Yes Yes No
The possible alarm conditions for multi-bit binary input direct records are the SCAN and READ alarms. These 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. No fields exist for the mbbi direct record to have state alarms.
"Alarm Fields" lists other fields related to a alarms that are common to all record types.
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. SVAL 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.
Clears MASK and then sets the NOBT low order bits.
If device support includes init_record(), it is called.
refresh_bits is then called to refresh all the bit fields based on a hardware value.
See next section.
Routine process implements the following algorithm:
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.
readValue is called. See "Output Records" for information.
If PACT has been changed to TRUE, the device support read routine has started but has not completed reading a new input value. In this case, the processing routine merely returns, leaving PACT TRUE.
Convert.
status = read_mbbiDirect
PACT = TRUE
recGblGetTimeStamp() is called.
If status is 0, then determine VAL
Set rval = RVAL
Shift rval right SHFT bits
Set VAL = RVAL
If status is 1, return 0
If status is 2, set status = 0
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 are checked whenever other monitors are invoked.
NSEV and NSTA are reset to 0.
Scan forward link if necessary, set PACT FALSE, and return.
Each input record must have an associated set of device support routines.
The primary responsibility of the device support routines is to obtain a new raw input value whenever read_mbbiDirect 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 VAL Current Value USHORT Yes Yes Yes Yes INP Input Specification INLINK Yes Yes Yes No RVAL Raw Value ULONG No Yes Yes Yes MASK Hardware Mask ULONG No Yes No No SHFT Shift USHORT Yes Yes Yes No
Device support consists of the following routines:
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.
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(precord)This routine is optional. If provided, it is called by the record support init_record() routine. If it uses MASK, it should shift it as necessary and also give SHFT a value.
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.
read_mbbiDirect(precord)This routine must provide a new input value. It returns the following values:
0: Success. A new raw value is placed in RVAL. The record support module determines VAL from RVAL and SHFT.
2: Success, but don't modify VAL.
Other: Error.
Two soft device support modules, Soft Channel and Raw Soft Channel, are provided for multi-bit binary input direct records not related to actual hardware devices. The INP link type must be either CONSTANT, DB_LINK, or CA_LINK.
For this module, read_mbbiDirect always returns a value of 2, which means that no conversion is performed.
If the INP link type is constant, then the constant value is stored into VAL by init_record(), and UDF is set to FALSE. VAL can be changed via dbPut requests. If the INP link type is PV_LINK, then dbCaAddInlink is called by init_record().
read_mbbiDirect calls recGblGetLinkValue to read the current value of VAL.
See "Input Records" for a further explanation.
If the return status of recGblGetLinkValue is zero, then read_mbbi sets UDF to FALSE. The status of recGblGetLinkValue is returned.
This module is like the previous except that values are read into RVAL, VAL is computed from RVAL, and read_mbbiDirect returns a value of 0. Thus the record processing routine will determine VAL in the normal way.