Long String Output Record (lso)

The long string output record is used to write an arbitrary ASCII string with a maximum length of 65535 characters.

Parameter Fields

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

Scan Parameters

The long string output record has the standard fields for specifying under what circumstances it will be processed. These fields are listed in "Scan Fields". In addition, "Scanning Specification" explains how these fields are used.

Desired Output Parameters

The long string output record must specify from where it gets its desired output string. The first field that determines where the desired output originates is the output mode select (OMSL) field, which can have two possible value: closed_loop or supervisory. If supervisory is specified, DOL is ignored, the current value of VAL is written, and VAL can be changed externally via dbPuts at run-time. If closed_loop is specified, the VAL field's value is obtained from the address specified in the desired output location field (DOL) which can be either a database link or a channel access link.

The maximum number of characters in VAL is given by SIZV, and cannot be larger than 65535.

DOL can also be a constant in addition to a link, in which case VAL is initialized to the constant value. Your string constant, however, may be interpreted as a CA link name. If you want to initialize your string output record, it is therefore best to use the VAL field. Note that if DOL is a constant, OMSL cannot be closed_loop.

See "Address Specification" for information on specifying links.

FieldSummaryTypeDCT DefaultReadWriteCA PP
VALCurrent ValueSTRING[SIZV]No YesYesYes
SIZVSize of buffersUSHORTYes41YesNoNo
DOLDesired Output LinkINLINKYes YesYesNo
OMSLOutput Mode SelectMENU (menuOmsl)Yes YesYesNo

Output Specification

The output link specified in the OUT field specifies where the long string output record is to write its string. The link can be a database or channel access link. If the OUT field is a constant, no output will be written.

See "Address Specification" for information on specifying links.

In addition, the appropriate device support module must be entered into the DTYP field.

FieldSummaryTypeDCT DefaultReadWriteCA PP
OUTOutput SpecificationOUTLINKYes YesYesNo
DTYPDevice TypeDEVICEYes YesYesNo

Monitor Parameters

These parameters are used to specify when the monitor post should be sent by the monitor() routine. There are two possible choices:

APST is used for archiver monitors and MPST for all other type of monitors.

FieldSummaryTypeDCT DefaultReadWriteCA PP
MPSTPost Value MonitorsMENU (menuPost)Yes YesYesNo
APSTPost Archive MonitorsMENU (menuPost)Yes YesYesNo

Operator Display Parameters

See "Fields Common to All Record Types" for more on the record name (NAME) and description (DESC) fields.

FieldSummaryTypeDCT DefaultReadWriteCA PP
NAMERecord NameSTRING [61]No YesNoNo
DESCDescriptorSTRING [41]Yes YesYesNo

Alarm Parameters

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

The IVOA field specifies an action to take when the INVALID alarm is triggered. There are three possible actions:

IndexIdentifierChoice String
0 menuIvoaContinue_normally Continue normally
1 menuIvoaDon_t_drive_outputs Don't drive outputs
2 menuIvoaSet_output_to_IVOV Set output to IVOV

When Set output to IVOV, the value contained in the IVOV field is written to the output link during an alarm condition. See "Invalid Alarm Output Action" for more information on the IVOA and IVOV fields. "Alarm Fields" lists other fields related to a alarms that are common to all record types.

FieldSummaryTypeDCT DefaultReadWriteCA PP
IVOAINVALID Output ActionMENU (menuIvoa)Yes YesYesNo
IVOVINVALID Output ValueSTRING [40]Yes YesYesNo

Run-time and Simulation Mode Parameters

The old value field (OVAL) of the long string input record is used to implement value change monitors for VAL. If VAL is not equal to OVAL, then monitors are triggered. LEN contains the length of the string in VAL, OLEN contains the length of the string in OVAL.

FieldSummaryTypeDCT DefaultReadWriteCA PP
OVALPrevious ValueSTRING[SIZV]No YesNoNo

The following fields are used to operate the string input in the simulation mode. See "Simulation Mode" for more information on simulation mode fields.

FieldSummaryTypeDCT DefaultReadWriteCA PP
SIOLSim Output SpecifctnOUTLINKYes YesYesNo
SIMLSim Mode linkINLINKYes YesYesNo
SIMMSimulation ModeMENU (menuYesNo)No YesYesNo
SIMSSim mode Alarm SvrtyMENU (menuAlarmSevr)Yes YesYesNo

Device Support Interface

The record requires device support to provide an entry table (dset) which defines the following members:

 typedef struct {
     long number;
     long (*report)(int level);
     long (*init)(int after);
     long (*init_record)(lsoRecord *prec);
     long (*get_ioint_info)(int cmd, lsoRecord *prec, IOSCANPVT *piosl);
     long (*write_string)(lsoRecord *prec);
 } lsodset;

The module must set number to at least 5, and provide a pointer to its write_string() routine; the other function pointers may be NULL if their associated functionality is not required for this support layer. Most device supports also provide an init_record() routine to configure the record instance and connect it to the hardware or driver support layer.

Device Support for Soft Records

Device support for DTYP Soft Channel is provided for writing values to other records or other software components.

Device support for DTYP stdio is provided for writing values to the stdout, stderr, or errlog streams. INST_IO addressing @stdout, @stderr or @errlog is used on the OUT link field to select the desired stream.