Binary Input Record (bi)¶
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.
Parameter Fields¶
The record-specific fields are described below, grouped by functionality.
Scan Parameters¶
The binary input record has the standard fields for specifying under what circumstances the record will be processed. These fields are described in Scan Fields.
Field |
Summary |
Type |
DCT |
Default |
Read |
Write |
CA PP |
|---|---|---|---|---|---|---|---|
SCAN |
Scan Mechanism |
MENU menuScan |
Yes |
Yes |
Yes |
No |
|
PHAS |
Scan Phase |
SHORT |
Yes |
Yes |
Yes |
No |
|
EVNT |
Event Name |
STRING [40] |
Yes |
Yes |
Yes |
No |
|
PRIO |
Scheduling Priority |
MENU menuPriority |
Yes |
Yes |
Yes |
No |
|
PINI |
Process at iocInit |
MENU menuPini |
Yes |
Yes |
Yes |
No |
Read and Convert Parameters¶
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.
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 [26] |
Yes |
Yes |
Yes |
Yes |
|
ONAM |
One Name |
STRING [26] |
Yes |
Yes |
Yes |
Yes |
|
RVAL |
Raw Value |
ULONG |
No |
Yes |
Yes |
Yes |
|
VAL |
Current Value |
ENUM |
Yes |
Yes |
Yes |
Yes |
Conversion Fields¶
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 [26] |
Yes |
Yes |
Yes |
Yes |
|
ONAM |
One Name |
STRING [26] |
Yes |
Yes |
Yes |
Yes |
Operator Display Parameters¶
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 [26] |
Yes |
Yes |
Yes |
Yes |
|
ONAM |
One Name |
STRING [26] |
Yes |
Yes |
Yes |
Yes |
|
NAME |
Record Name |
STRING [61] |
No |
Yes |
No |
No |
|
DESC |
Descriptor |
STRING [41] |
Yes |
Yes |
Yes |
No |
Alarm Parameters¶
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 NO_ALARM, MINOR, and
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.
See Alarm Specification for a complete explanation of record alarms and of the standard fields. Alarm Fields lists other fields related to alarms that are common to all record types.
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 |
Run-time Parameters¶
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 |
Simulation Mode Parameters¶
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 |
Record Support¶
Record Support Routines¶
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.
Record Processing¶
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 “Input Records” for details.
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_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
Check alarms: This routine checks to see if the new VAL causes the alarm status and severity to change. If so, NSEV, NSTA and LALM are set. Note that if VAL is greater than 1, no checking is performed.
Check 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 MSLT 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.
Device Support¶
Fields of Interest to Device Support¶
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 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.
long init_record(struct dbCommon *precord);
This routine is optional. If provided, it is called by the record support
init_record() routine.
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:
0: Success. A new raw value is placed in RVAL. The record support module forces VAL to be (0,1) if RVAL is (0, not 0).
2: Success, but don’t modify VAL.
Other: Error.
Device Support for Soft Records¶
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.
Soft Channel¶
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 init_record().
read_bi() calls 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.
Raw Soft Channel¶
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.