Create an allowlist

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

Allowlists can contain a select number of points from a select number of records, or you can use them to configure the writable status of all RealTime database (RTDB) records. Because you create it, an allowlist is flexible to the needs of any instance of the Open Platform Communications (OPC) Server.

Before you write the allowlist, you will need to consider the objectives for its use with the OPC Server instance to which it will be applied. This might mean analysis of the points in RTDB and the groups to which these points belong. All of the records in the RTDB are candidates for an allowlist. Planning the objectives of the allowlist is the first step, and should include verification of the names and spelling of the tables and points the allowlist will include.

To create an allowlist

1. In the %DNADataRoot%\RealTime\config\Settings directory, either create or open the OPCDAWhiteList.json file.

2. Create an array of points to allow list (for example, {"table":"analog","ptname":"1Analog","writeable":"READONLY"},).

   The writeable setting can be set to either READWRITE or READONLY.

   Note: This part of the JSON object is case-sensitive.

3. Add additional entries on a new line.

4. Save the allowlist when it is complete.

Example:

{

"RealTime":{

"OPCDAServer":{

"OASySDNA.OPCDAServer.1":{

"Whitelist":[

{"table":"analog","ptname":"0Analog","writeable":"READWRITE"},

{"table":"analog","ptname":"1Analog","writeable":"READONLY"},

{"table":"analog","ptname":"2Analog","writeable":"READONLY"},

{"table":"status","ptname":"0Status","writeable":"READWRITE"},

{"table":"status","ptname":"1Status","writeable":"READONLY"},

{"table":"status","ptname":"2Status","Writeable":"READONLY"}

]

}

}

}

}