Configure a packed<table>Rt virtual field

Note: For information on overriding default configuration settings, refer to Modify configuration settings.

The VirtualFieldList key is defined in the PIOASyS_VirtualFieldList.json file located in the %DNAInstallRoot%\Realtime\Config\Settings directory. The key contains a list of RealTime database (RTDB) tables with published virtual fields containing packed data. Additional field data values are specified and returned after the packed data. The combined packed data and field value(s) are sent as a blob.

The following example is from the PIOASyS_VirtualFieldList.json file under the %DNAInstallRoot%\Realtime\Config\Settings directory.

{

"PIOASYS": {

"VirtualFieldList": {

"analog":{

"packedField": "packedAnalogRt",

"fields": ["curval"]

},

"status":{

"packedField": "",

"fields": ["cursta@raw"]

},

"rate":{

"packedField": "packedRateRt",

"fields": ["currate", "acccur"]

},

"multistate":{

"packedField": "packedMultistateRt",

"fields": ["inputCurRaw"]

}

}

}

}

Where:

• analog, status, rate, and multistate are the RTDB tables.

• "packedField" is the optional name of the published virtual field containing the packed data. For example, if the table is rate, the "packedField" is "packedRateRt".

  Note: If this line is omitted, <packed<table>Rt> will be used implicitly with the first letter of the table capitalized.

• "fields": is an array of fields to be returned after the packed data. Each field is assigned to a numeric index. No duplicates are allowed. Fields are returned in the same order in which they appear in the array:

  "fields": ["<field 1>", "<field 2>"]

  If you want to skip an item, omit the entry by leaving an empty string for the field name:

  "fields": ["", "<field 2>"]

  Note: The PI tag’s ExDesc configuration should contain a path to one of these field names. For example, if 1=currate is specified for the [rate] table, then ExDesc can be rate.example.currate.