The normal use for the multi-bit binary input record is to read contiguous, multiple bit inputs from hardware. The binary value represents a state from a range of up to 16 states. The multi-bit input record interfaces with devices that use more than one bit.
Most device support modules obtain values from hardware and place the value in RVAL. For these device support modules record processing uses RVAL to determine the current state (VAL is given a value between 0 and 15). Device support modules may optionally read a value directly into VAL.
Soft device modules are provided to obtain input via database or channel access links or via dbPutField or dbPutLink requests.
Two soft device support modules are provided: Soft Channel allows VAL to be an arbitrary unsigned short integer.
Raw Soft Channel reads the value into RVAL just like normal device support modules.
The record-specific fields are described below, grouped by functionality.
The multi-bit binary input record has the standard fields for specifying under what circumstances it will be processed. These fields are listed in Scan Fields.
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.
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 mbbi 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 constant value but can be changed at run-time via dbPutField or dbPutLink.
MASK is used by the raw soft channel read routine, and by typical device support read routines, to select only the desired bits when reading the hardware register. It is initialized to ((1 << NOBT) - 1) by record initialization. The user can configure the NOBT field, but the device support routines may set it, in which case the value given to it by the user is simply overridden. The device support routines may also override MASK or shift it left by SHFT bits. If MASK is non-zero, only the bits specified by MASK will appear in RVAL.
Unless the device support routine specifies no conversion, RVAL is used to determine VAL as follows:
Each of the fields, ZRVL-FFVL, represents one of the possible sixteen states (not all sixteen have to be used).
Alternatively, the input value can be read as a string, in which case, a match is sought with one of the strings specified in the ZRST-FFST fields. Then RVAL is set equal to the corresponding value for that string, and the conversion process occurs.
Field Summary Type DCT Default Read Write CA PP VAL Current Value ENUM Yes Yes Yes Yes INP Input Specification INLINK Yes Yes Yes No MASK Hardware Mask ULONG No Yes No No NOBT Number of Bits USHORT Yes Yes No No RVAL Raw Value ULONG No Yes Yes Yes SHFT Shift USHORT Yes Yes Yes No ZRVL Zero Value ULONG Yes Yes Yes Yes ONVL One Value ULONG Yes Yes Yes Yes TWVL Two Value ULONG Yes Yes Yes Yes THVL Three Value ULONG Yes Yes Yes Yes FRVL Four Value ULONG Yes Yes Yes Yes FVVL Five Value ULONG Yes Yes Yes Yes SXVL Six Value ULONG Yes Yes Yes Yes SVVL Seven Value ULONG Yes Yes Yes Yes EIVL Eight Value ULONG Yes Yes Yes Yes NIVL Nine Value ULONG Yes Yes Yes Yes TEVL Ten Value ULONG Yes Yes Yes Yes ELVL Eleven Value ULONG Yes Yes Yes Yes TVVL Twelve Value ULONG Yes Yes Yes Yes TTVL Thirteen Value ULONG Yes Yes Yes Yes FTVL Fourteen Value ULONG Yes Yes Yes Yes FFVL Fifteen Value ULONG Yes Yes Yes Yes
These parameters are used to present meaningful data to the operator.
They display the value and other parameters of the mbbi record either textually or graphically.
The ZRST-FFST fields contain strings describing one of the possible states of the record.
The get_enum_str and get_enum_strs record routines retrieve these strings for the operator.
Get_enum_str gets the string corresponding to the value set in VAL,
and get_enum_strs retrieves all the strings.
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 ZRST Zero String STRING [26] Yes Yes Yes Yes ONST One String STRING [26] Yes Yes Yes Yes TWST Two String STRING [26] Yes Yes Yes Yes THST Three String STRING [26] Yes Yes Yes Yes FRST Four String STRING [26] Yes Yes Yes Yes FVST Five String STRING [26] Yes Yes Yes Yes SXST Six String STRING [26] Yes Yes Yes Yes SVST Seven String STRING [26] Yes Yes Yes Yes EIST Eight String STRING [26] Yes Yes Yes Yes NIST Nine String STRING [26] Yes Yes Yes Yes TEST Ten String STRING [26] Yes Yes Yes Yes ELST Eleven String STRING [26] Yes Yes Yes Yes TVST Twelve String STRING [26] Yes Yes Yes Yes TTST Thirteen String STRING [26] Yes Yes Yes Yes FTST Fourteen String STRING [26] Yes Yes Yes Yes FFST Fifteen String STRING [26] Yes Yes Yes Yes
The possible alarm conditions for multi-bit binary inputs are the SCAN, READ, and state alarms. The state alarms are configured in the below severity fields. These fields have the usual possible values for severity fields: NO_ALARM, MINOR, and MAJOR.
The unknown state severity (UNSV) field,
if set to MINOR or MAJOR,
triggers an alarm when the record support routine cannot find a matching value in the state value fields for rval.
The change of state severity (COSV) field triggers an alarm when any change of state occurs, if set to MAJOR or MINOR.
The other fields, when set to MAJOR or MINOR, trigger an alarm when VAL equals the corresponding state. See the See "Alarm Specification" for a complete explanation of discrete alarms and these fields. 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 UNSV Unknown State Severity MENU (menuAlarmSevr) Yes Yes Yes Yes COSV Change of State Svr MENU (menuAlarmSevr) Yes Yes Yes Yes ZRSV State Zero Severity MENU (menuAlarmSevr) Yes Yes Yes Yes ONSV State One Severity MENU (menuAlarmSevr) Yes Yes Yes Yes TWSV State Two Severity MENU (menuAlarmSevr) Yes Yes Yes Yes THSV State Three Severity MENU (menuAlarmSevr) Yes Yes Yes Yes FRSV State Four Severity MENU (menuAlarmSevr) Yes Yes Yes Yes FVSV State Five Severity MENU (menuAlarmSevr) Yes Yes Yes Yes SXSV State Six Severity MENU (menuAlarmSevr) Yes Yes Yes Yes SVSV State Seven Severity MENU (menuAlarmSevr) Yes Yes Yes Yes EISV State Eight Severity MENU (menuAlarmSevr) Yes Yes Yes Yes NISV State Nine Severity MENU (menuAlarmSevr) Yes Yes Yes Yes TESV State Ten Severity MENU (menuAlarmSevr) Yes Yes Yes Yes ELSV State Eleven Severity MENU (menuAlarmSevr) Yes Yes Yes Yes TVSV State Twelve Severity MENU (menuAlarmSevr) Yes Yes Yes Yes TTSV State Thirteen Sevr MENU (menuAlarmSevr) Yes Yes Yes Yes FTSV State Fourteen Sevr MENU (menuAlarmSevr) Yes Yes Yes Yes FFSV State Fifteen Severity MENU (menuAlarmSevr) Yes Yes Yes Yes
These parameters are used by the run-time code for processing the multi-bit binary input.
ORAW is used by record processing to hold the prior RVAL for use in determining when to post a monitor event for the RVAL field.
The LALM field implements the change of state alarm severity by holding the value of VAL when the previous change of state alarm was issued.
MLST holds the value when the last monitor for value change was triggered.
SDEF is used by record support to save time if no states are defined.
Field Summary Type DCT Default Read Write CA PP ORAW Prev Raw Value ULONG No Yes No No LALM Last Value Alarmed USHORT No Yes No No MLST Last Value Monitored USHORT No Yes No No SDEF States Defined SHORT No Yes No No
The following fields are used to operate the record in simulation mode.
If SIMM (fetched through SIML) is YES or RAW, the record is put in SIMS severity and the value is fetched through SIOL (buffered in SVAL). If SIMM is YES, SVAL is written to VAL without conversion, if SIMM is RAW, SVAL is trancated to RVAL and converted. 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 Input 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 (menuSimm) No Yes Yes No SIOL Simulation Input Link INLINK Yes Yes Yes No SVAL Simulation Value ULONG No 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
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.
init_common is then called to determine if any states are defined. If states are defined, SDEF is set to TRUE.
See next section.
Calls init_common to compute SDEF when any of the fields ZRVL, ... FFVL change value.
Retrieves ASCII string corresponding to VAL.
Retrieves ASCII strings for ZRST,...FFST.
Checks if string matches ZRST,...FFST and if it does, sets VAL.
Routine process implements the following algorithm:
recGblGetTimeStamp() is called.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_mbbi 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 USHORT Yes Yes No No VAL Current Value ENUM 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 I/O Event scanner.
read_mbbi(precord)
This routine must provide a new input value. It returns the following values:
Two soft device support modules Soft Channel and Raw Soft Channel are provided for multi-bit binary input records not related to actual hardware devices. The INP link type must be either CONSTANT, DB_LINK, or CA_LINK.
read_mbbi 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_mbbi calls recGblGetLinkValue to read the current value of VAL. See "Soft Input".
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_mbbi returns a value of 0. Thus the record processing routine will determine VAL in the normal way.