Disable alarm at IOC via PVAccess

[David Bracey via Tech-talk <tech-talk@aps.anl.gov>]

Is it possible to disable a PV’s alarm at the IOC, using PVAccess, on a “stock” IOC/PV?  (i.e. no custom code added)

 

I see that using channel access, one can disable the entire PV (via the DISV/DISA db fields) – however we are not using channel access.

 

Defining a simple DB record for a PV:

 

record(ai, "VAL1") {

    field(VAL, "1")

    field(SCAN, "1 second")

    field(HIHI, "2")

    field(LOLO, "0")

    field(HHSV, "MAJOR")

    field(LLSV, "MINOR")

}

One gets the following from pvxget:

 

VAL1

    value double = 1

    alarm.severity int32_t = 0

    alarm.status int32_t = 0

    alarm.message string = ""

    timeStamp.secondsPastEpoch int64_t = 1763589981

    timeStamp.nanoseconds int32_t = 529070863

    timeStamp.userTag int32_t = 0

    display.limitLow double = 0

    display.limitHigh double = 0

    display.description string = ""

    display.units string = ""

    display.precision int32_t = 0

    display.form.index int32_t = 0

    display.form.choices string[] = {7}["Default", "String", "Binary", "Decimal", "Hex", "Exponential", "Engineering"]

    control.limitLow double = 0

    control.limitHigh double = 0

    valueAlarm.lowAlarmLimit double = 0

    valueAlarm.lowWarningLimit double = nan

    valueAlarm.highWarningLimit double = nan

    valueAlarm.highAlarmLimit double = 2

 

From reading the docs, I gather that before the valueAlarm_t type, there used to be an alarmLimit_t type, which had an “enable” field – but currently I don’t see a way to do this besides possibly resetting the valueAlarm limits, and I don’t want to do that.

 

Can anyone recommend a way to disable the alarm at the IOC, given these coditions?

 

Thanks!

 

• Dave Bracey, Fermilab AD