Event Record (event)

The normal use for this record type is to post an event and/or process a forward link. Device support for this record can provide a hardware interrupt handler routine for I/O Event-scanned records.

Parameter Fields

The record-specific fields are described below, grouped by functionality.

Scan Parameters

The event record has the standard fields for specifying under what circumstances it will be processed. If the SCAN field specifies I/O Intr, then device support will provide an interrupt handler, posting an event number when an I/O interrupt occurs. These fields are listed in Scan Fields.

Event Number Parameters

The VAL field contains the event number read by the device support routines. It is this number which is posted. For records that use Soft Channel device support, it can be configured before run-time or set via dbPuts.

Field	Summary	Type	DCT	Default	Read	Write	CA PP
VAL	Event Name To Post	STRING [40]	Yes		Yes	Yes	No

Input Specification

The device support routines use the address in this record to obtain input. For records that provide an interrupt handler, the INP field should specify the address of the I/O card, and the DTYP field should specify a valid device support module. Be aware that the address format differs according to the card type used. See "Address Specification" for information on the format of hardware addresses and specifying links.

For soft records, the INP field can be a constant, a database link, or a channel access link. For soft records, the DTYP field should specify Soft Channel.

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

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

Alarm Parameters

The Event record has the alarm parameters common to all record types. "Alarm Fields" lists other fields related to alarms that are common to all record types.

Simulation Mode Parameters

The following fields are used to operate the event 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	STRING [40]	No		Yes	Yes	No
SIML	Sim Mode Location	INLINK	Yes		Yes	Yes	No
SIMM	Simulation Mode	MENU (menuYesNo)	No		Yes	Yes	No
SIMS	Sim mode Alarm Svrty	MENU (menuAlarmSevr)	Yes		Yes	Yes	No

Record Support

Record Support Routines

init_record

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 CONSTANT or PV_LINK.

If device support includes init_record(), it is called.

process

See next section.

Record Processing

Routine process implements the following algorithm:

1. readValue is called. See "Input Records" for more information.
2. 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.
3. If VAL > 0, post event number VAL.
4. Check to see if monitors should be invoked. Alarm monitors are invoked if the alarm status or severity has chanet to 0.
5. Scan forward link if necessary, set PACT FALSE, and return.

Device Support

Fields of Interest To Device Support

Each record must have an associated set of device support routines. 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
INP	Input Specification	INLINK	Yes		Yes	Yes	No
PRIO	Scheduling Priority	MENU (menuPriority)	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.

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.

read_event

  read_event(precord)

This routine returns the following values:

• 0: Success.
• Other: Error.

Device Support For Soft Records

The Soft Channel device support module is available. The INP link type must be either CONSTANT, DB_LINK, or CA_LINK.

If the INP link type is CONSTANT, then the constant value is stored into VAL by init_record(), and UDF is set to FALSE. If the INP link type is PV_LINK, then dbCaAddInlink is called by init_record().

read_event calls recGblGetLinkValue to read the current value of VAL. See "Input Records" for details on soft input.