Experimental Physics and
Industrial Control System

Hi all,

Today I encountered something kind of interesting and would like to get some outside opinions.

To begin with, I have an IOC for an instrument that I shall call DemoInstr. I have a “setter” and “getter” record for one of its properties. The two records are shown below.

record(ao, “SET_PROP”)

{

                field(SCAN, “Passive”)

                field(DTYP, “stream”)

field(PRIO, "HIGH")

                field(OUT,  "@DemoInstr.proto setProp $(PORT)")

                field(FLNK, “GET_PROP”)

}

record(ai, “GET_PROP”)

{

                field(SCAN, “Passive”)

                field(DTYP, “stream”)

                field(INP,  "@DemoInstr.proto getProp $(PORT)")

}

In a separate IOC that I shall call Setup, I declared a SEQ record called “WRITE_INST” that should write a value into “setProp” when it is processed. Then, “PROCESS_INST”, a SSEQ record, will process because it is forward-linked to “WRITE_INST”. “PROCESS_INST” should wait for a completion callback with the way it is written. However, when “PRINT_SET_AND_GET” processes, it reports that GET_PROP still contains the previous value. Shouldn’t GET_PROP have been updated because of the completion callback? I feel like I am missing something in my understanding of completion callbacks.

record(ao, “VAL”)

{

                field(SCAN, “Passive”)

}

record(seq, "WRITE_INST")

{

                field(SCAN, "Passive")

                field(SELM, "All")

                field(DOL1, “VAL")

                field(LNK1, "SET_PROP")

                field(FLNK, “PROCESS_INST ")

}

record(sseq, “PROCESS_INST")

{

                field(SCAN,  "Passive")

                field(SELM,  "All")

                field(LNK1,  "SET_PROP.PROC CA")

                field(WAIT1, "Wait")

                field(FLNK, “PRINT_SET_AND_GET”)

}

record(aSub, “PRINT_SET_AND_GET")

{

                field(SCAN,  "Passive")

                field(SNAM, “print_set_and_get”)

                field(INPA, “SET_PROP”)

                field(INPB, “GET_PROP”)

}

Thank you,

Andy

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