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. 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

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.