PingURL
The PingURL method provides a way for an OAS Outage Analysis System to test that it can communicate with VTScada’s MultiSpeak web service. VTScada will respond with a PingURLResponse. An empty response with an empty <PingURlResult>, i.e. with no error content, means success.
VTScada also sends PingURL requests to an OAS in order to verify that it is alive. For example, if a notification is sent by VTScada, but no response is recieved before a preset time, VTScada will send a number of PingURL requests to verify whether the OAS is online before giving up.
When the MultiSpeak service starts, and assuming that a subscription is valid(*), it will send successive PingURLs, separated by MultiSpeakMessageTimeout pauses, until one succeeds. The service will then immediately send a GetMethods request. If the GetMethods request fails, the cycle PingURL / GetMethods will restart until GetMethods succeeds. If a notification fails, the PingURL / GetMethods cycle restarts until a GetMethods request succeeds.
A sample PingURL request coming from an OAS:
POST http://MultiSRV/MultiSpeakRealm1/ HTTP/1.1 Connection:Keep-Alive Content-Type:text/xml; charset=utf-8 Accept:text/* Authorization:Basic YTph User-Agent:SOAPWinHTTPClient SOAPAction:"http://www.multispeak.org/Version_4.1_Release/PingURL" Content-Length:879 Host:MultiSRV
An example of a corresponding PingURLResponse returned from VTScada:
HTTP/1.1 200 OK Date: Mon, 25 Jan 2021 20:10:24 GMT Server: VTScada 12.0.26 Content-Type: text/xml; charset="utf-8" Content-Length: 1152 Cache-Control: no-cache, no-store