Typical IoT systems have been based on dedicated sensor networks. Gateways (GW) have been designed to route to server the entire communication message by message, without any processing. Further, automatic discovery of sensors has often been used. Data buffering has been used to cope with temporary communication failures only. Modern mining equipment contain electronic control systems, which provide various kinds of data for monitoring. In each site there may be numerous kinds of equipment, each providing different data as different sets. Especially in underground mines, there are areas without any communication network available due to a harsh conditions. This paper presents a new GW concept, which has intentionally been designed to provide a flexible connectivity to various equipment, networks and servers. Intentionally selected data will be extracted into a source independent format. Data buffered by the GW may be sent to the remote server, when a connection exists. Configurability requires well defined management processes to result reliable operation. This paper presents process examples for three major alternative connections, J1939 fleet management, CAN-based superstructure network and a CANopen sensor network. Field tests proved, that the presented GW concept reached the defined targets. The presented configuration processes improved getting the GWs configured without errors.