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.
The records in this field fall into the following groups of parameters:
event number parameters
simulation mode 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". In addition, "Scanning Specification" explains how the scanning fields work. Note that I/O event scanning is only supported for those card types that interrupt.
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  Yes Yes Yes No
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
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
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  No Yes No No DESC Descriptor STRING  Yes Yes Yes No
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.
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  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
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.
See next section.
Routine process implements the following algorithm:
readValue is called. See "Input Records" for more information.
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.
If VAL > 0, post event number VAL.
Check to see if monitors should be invoked. Alarm monitors are invoked if the alarm status or severity has chanet to 0.
Scan forward link if necessary, set PACT FALSE, and return.
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 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.
This routine is optional. If provided, it is called by the record support
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.
This routine returns the following values:
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
read_event calls recGblGetLinkValue to read the current value of VAL. See "Input Records" for details on soft input.