This record type is normally used to obtain a binary value of 0 or 1. Most device support modules obtain values from hardware and place the value in RVAL. For these devices, record processing sets VAL = (0,1) if RVAL is (0, not 0). Device support modules may optionally read a value directly from VAL.
Soft device modules are provided to obtain input via database or channel access links via dbPutField or dbPutLink requests. Two soft device support modules are provided:
Soft Channel and
Raw Soft Channel. The first allows VAL to be an arbitrary unsigned short integer. The second reads the value into RVAL just like normal hardware modules.
The binary input's fields fall into the following categories:
read and convert parameters
operator display parameters
The binary input 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.
Field Summary Type DCT Default Read Write CA PP SCAN Scan Mechanism MENU (menuScan) Yes Yes Yes No
The read and convert fields determine where the binary input gets its input from and how to convert the raw signal to engineering units. The INP field contains the address from where device support retrieves the value. If the binary input record gets its value from hardware, the address of the card must be entered in the INP field, and the name of the device support module must be entered in the DTYP field. See "Address Specification" for information on the format of the hardware address. Be aware that the format differs between types of cards.
For records that specify
Soft Channel or
Raw Soft Channel device support routines, the INP field can be a channel or a database link, or a constant. If a constant, VAL can be changed directly by dbPuts. See "Address Specification" for information on the format of database and channel access addresses. Also, see "Device Support for Soft Records" in this chapter for information on soft device support.
If the record gets its values from hardware or uses the
Raw Soft Channel device support, the device support routines place the value in the RVAL field which is then converted using the process described in the next section.
Field Summary Type DCT Default Read Write CA PP INP Input Specification INLINK Yes Yes Yes No DTYP Device Type DEVICE Yes Yes Yes No ZNAM Zero Name STRING  Yes Yes Yes Yes ONAM One Name STRING  Yes Yes Yes Yes RVAL Raw Value ULONG No Yes Yes Yes VAL Current Value ENUM Yes Yes Yes Yes
The VAL field is set equal to (0,1) if the RVAL field is (0, not 0), unless the device support module reads a value directly into VAL or the
Soft Channel device support is used. The value can also be fetched as one of the strings specified in the ZNAM or ONAM fields. The ZNAM field has a string that corresponds to the 0 state, so when the value is fetched as this string,
put_enum_str() will return a 0. The ONAM field hold the string that corresponds to the 1 state, so when the value is fetched as this string,
put_enum_str() returns a 1.
Field Summary Type DCT Default Read Write CA PP ZNAM Zero Name STRING  Yes Yes Yes Yes ONAM One Name STRING  Yes Yes Yes Yes
These parameters are used to present meaningful data to the operator. The
get_enum_str() record support routine can retrieve the state string corresponding to the VAL's state. If the value is 1,
get_enum_str() will return the string in the ONAM field; and if 0,
get_enum_str() will return the ZNAM string.
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 ZNAM Zero Name STRING  Yes Yes Yes Yes ONAM One Name STRING  Yes Yes Yes Yes NAME Record Name STRING  No Yes No No DESC Descriptor STRING  Yes Yes Yes No
These parameters are used to determine if the binary input is in alarm condition and to determine the severity of that condition. The possible alarm conditions for binary inputs are the SCAN, READ state alarms, and the change of state alarm. The SCAN and READ alarms are called by the device supprt routines.
The user can choose the severity of each state in the ZSV and OSV fields. The possible values for these fields are
MAJOR. The ZSV field holds the severity for the zero state; OSV, for the one state. COSV causes an alarm whenever the state changes between 0 and 1 and the severity is configured as MINOR or MAJOR.
Field Summary Type DCT Default Read Write CA PP ZSV Zero Error Severity MENU (menuAlarmSevr) Yes Yes Yes Yes OSV One Error Severity MENU (menuAlarmSevr) Yes Yes Yes Yes COSV Change of State Svr MENU (menuAlarmSevr) Yes Yes Yes Yes
These parameters are used by the run-time code for processing the binary input. They are not configured using a database configuration tool.
ORAW is used to determine if monitors should be triggered for RVAL at the same time they are triggered for VAL.
MASK is given a value by ithe device support routines. This value is used to manipulate the record's value, but is only the concern of the hardware device support routines.
The LALM fields holds the value of the last occurence of the change of state alarm. It is used to implement the change of state alarm, and thus only has meaning if COSV is MAJOR or MINOR.
The MSLT field is used by the
process() record support routine to determine if archive and value change monitors are invoked. They are if MSLT is not equal to VAL.
Field Summary Type DCT Default Read Write CA PP ORAW prev Raw Value ULONG No Yes No No MASK Hardware Mask ULONG No Yes No No LALM Last Value Alarmed USHORT No Yes No No MLST Last Value Monitored USHORT No Yes No No
The following fields are used to operate the binary input in 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
long init_record(struct dbCommon *precord, int pass);
This routine initializes SIMM with the value of SIML if SIML type is a CONSTANT link or creates a channel access link if SIML type is PV_LINK. SVAL is likewise initialized if SIOL is a CONSTANT or PV_LINK.
This routine next checks to see that device support is available and a device support routine is defined. If neither exist, an error is issued and processing is terminated.
If device support includes
init_record(), it is called.
long process(struct dbCommon *precord);
See "Record Processing" below.
long get_enum_str(const struct dbAddr *paddr, char *pbuffer);
Retrieves ASCII string corresponding to VAL.
long get_enum_strs(const struct dbAddr *paddr, struct dbr_enumStrs *p);
Retrieves ASCII strings for ZNAM and ONAM.
long put_enum_str(const struct dbAddr *paddr, const char *pbuffer);
Check if string matches ZNAM or ONAM, and if it does, sets VAL.
Routine process implements the following algorithm:
readValue()is called. See "Input Records" for details.
status = read_bi
PACT = TRUE
recGblGetTimeStamp() is called.
if status is 0, then set VAL=(0,1) if RVAL is (0, not 0) and UDF = False.
if status is 2, set status = 0
Alarm monitors are invoked if the alarm status or severity has changed.
Archive and value change monitors are invoked if MSLT is not equal to VAL.
Monitors for RVAL are checked whenever other monitors are invoked.
NSEV and NSTA are reset to 0.
Each binary input record must have an associated set of device support routines. The primary resposibility of the device support routines is to obtain a new raw input value whenever
read_bi() 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 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
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.
long init_record(struct dbCommon *precord);
This routine is optional. If provided, it is called by the record support
long 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) and I/O event list. It must be provided for any device type that can use the ioEvent scanner.
long read_bi(struct dbCommon *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 input records not related to actual hardware devices. The INP link type must be either CONSTANT, DB_LINK, or CA_LINK.
read_bi() 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 in VAL by
init_record(), and the UDF is set to FALSE. VAL can be changed via
dbPut() requests. If the INP link type is PV_LINK, the
dbCaAddInlink() is called by
dbGetLinkValue to read the current value of VAL. See "Soft Input" for details.
If the return status of
dbGetLinkValue() is zero, then
read_bi() sets UDF to FALSE. The status of
dbGetLinkValue() is returned.
This module is like the previous except that values are read into RVAL.
read_bi() returns a value of 0. Thus the record processing routine will force VAL to be 0 or 1.