To whom it may concern,

 

I’m attempting to create custom PVStructures which contain differing normative types. At the moment, I’ve created the below code in an IOC which creates a PV Structure with 2 NTScalars and 1 NTScalarArray.

 

record(ai, "rec:X") {

               field(VAL, "20")

               field(HIGH, "30")

               field(HSV, "MINOR")

               info(Q:group, {

                              "CustomDataStructure": {

                                             "X_Scalar": {

                                                            +channel:"VAL"

                                             }

                              }

               })

}

record(ai, "rec:Y") {

               field(VAL, "40") 

               info(Q:group, {

                              "CustomDataStructure": {

                                             "Y_Scalar": {

                                                            +type:"scalar",                  

                                                            +channel:"VAL",

                                                            +id:"MyTestingPVA2PVA",

                                             }

                              }

               })

}

 

record(aai, "input_this") {

               field(NELM, "4")

               field(FTVL, "INT64")

               field(INP, "[1,2,3,4]")

               info(Q:group, {

                              "CustomDataStructure": {

                                             "Z_Aray": {

                                                            +channel:"VAL"

                                             }

                              }

               })

 

}

 

At the moment, this does create the PV Structure, and I can access it through “pvget”. However I’m unsure if this is the right way to do this. Can someone with more experience with Epics v7 correct me if so? Also, I’m not sure how to go about accessing parts of “CustomDataStructure”. Namely how would I go about accessing the value for Y_Scalar through CustomDataStructure?

 

I’ve also copied the output of pvget below. I apologize for the lengthy post, but I thought it was best to provide as much context as possible.

 

• pvget CustomDataStructure

CustomDataStructure MyTestingPVA2PVA

    structure record

        structure _options

            uint queueSize 0

            boolean atomic true

    epics:nt/NTScalar:1.0 X_Scalar

        double value 20

        alarm_t alarm

            int severity 0

            int status 2

            string message UDF

        structure timeStamp

            long secondsPastEpoch 631152000

            int nanoseconds 0

            int userTag 0

        structure display

            double limitLow 0

            double limitHigh 0

            string description

            string units

            int precision 0

            enum_t form (0) Default

                int index 0

                string[] choices [Default, String, Binary, Decimal, Hex, Exponential, Engineering]

        control_t control

            double limitLow 0

            double limitHigh 0

            double minStep 0

        valueAlarm_t valueAlarm

            boolean active false

            double lowAlarmLimit nan

            double lowWarningLimit nan

            double highWarningLimit 30

            double highAlarmLimit nan

            int lowAlarmSeverity 0

            int lowWarningSeverity 0

            int highWarningSeverity 0

            int highAlarmSeverity 0

            byte hysteresis 0

    epics:nt/NTScalar:1.0 Y_Scalar

        double value 40

        alarm_t alarm

            int severity 0

            int status 2

            string message UDF

        structure timeStamp

            long secondsPastEpoch 631152000

            int nanoseconds 0

            int userTag 0

        structure display

            double limitLow 0

            double limitHigh 0

            string description

            string units

            int precision 0

            enum_t form (0) Default

                int index 0

                string[] choices [Default, String, Binary, Decimal, Hex, Exponential, Engineering]

        control_t control

            double limitLow 0

            double limitHigh 0

            double minStep 0

        valueAlarm_t valueAlarm

            boolean active false

            double lowAlarmLimit nan

            double lowWarningLimit nan

            double highWarningLimit nan

            double highAlarmLimit nan

            int lowAlarmSeverity 0

            int lowWarningSeverity 0

            int highWarningSeverity 0

            int highAlarmSeverity 0

            byte hysteresis 0

    epics:nt/NTScalarArray:1.0 Z_Scalar

        long[] value [1,2,3,4]

        alarm_t alarm INVALID DRIVER UDF

            int severity 3

            int status 2

            string message UDF

        structure timeStamp

            long secondsPastEpoch 631152000

            int nanoseconds 0

            int userTag 0

        structure display

            double limitLow 0

            double limitHigh 0

            string description

            string units

            int precision 0

            enum_t form (0) Default

                int index 0

                string[] choices [Default, String, Binary, Decimal, Hex, Exponential, Engineering]

        control_t control

            double limitLow 0

            double limitHigh 0

            double minStep 0

        valueAlarm_t valueAlarm

            boolean active false

            double lowAlarmLimit nan

            double lowWarningLimit nan

            double highWarningLimit nan

            double highAlarmLimit nan

            int lowAlarmSeverity 0

            int lowWarningSeverity 0

            int highWarningSeverity 0

            int highAlarmSeverity 0

            byte hysteresis 0

 

Sincerely,

 

Dhruv Srinivas

srinivas1 at llnl.gov