README.md

About the "NetworkTime" sample

The "NetworkTime" sample extension is a server extension that can query an NTP server. It uses the "RequestListener" interface to provide a single function symbol called "Now" that fetches the current timestamp from the NTP server and returns it. The NTP server URL is stored in the extension configuration at path NetworkTime.Config::ntpServer.

First steps:

• Working with server extensions
• Interacting with a server extension

Example requests

1. Get the current time from the configured NTP server.

   Request:

   {
       "requestType": "ReadWrite",
       "commands": [
           {
               "symbol": "NetworkTime.Now",
               "commandOptions": [ "SendErrorMessage" ]
           }
       ]
   }

   Response:

   {
       "commands": [
           {
               "symbol": "NetworkTime.Now",
               "readValue": "2020-12-28T06:41:54.587Z"
           }
       ]
   }

2. Get the configured NTP server URL.

   Request:

   {
       "requestType": "ReadWrite",
       "commands": [
           {
               "symbol": "NetworkTime.Config::ntpServer",
               "commandOptions": [ "SendErrorMessage" ]
           }
       ]
   }

   Response:

   {
       "commands": [
           {
               "symbol": "NetworkTime.Config::ntpServer",
               "readValue": "ntp.beckhoff-cloud.com"
           }
       ]
   }

3. Change the configured NTP server URL.

   Request:

   {
       "requestType": "ReadWrite",
       "commands": [
           {
               "symbol": "NetworkTime.Config::ntpServer",
               "writeValue": "time.windows.com",
               "commandOptions": [ "SendErrorMessage", "SendWriteValue" ]
           }
       ]
   }

   Response:

   {
       "commands": [
           {
               "symbol": "NetworkTime.Config::ntpServer",
               "readValue": "time.windows.com"
           }
       ]
   }