Cast node character limit

General
2

you can send audio file using the following msg properties. There is a heep of more info here , file types etc.

msg.payload.url = "http://192.168.0.4:1880/alert5.mp3";
msg.payload.volume = 50;
msg.payload.contentType = "audio/mp3";
msg.payload.ip = "192.168.0.19";
msg.payload["port"] = 8009;

The file are stored in the httpStatic directory
more info here
https://nodered.org/docs/user-guide/runtime/configuration#runtime-configuration