gw: RTCU Communication Hub / Gateway

The RTCU Communication Hub functions are used for establishing a connection to the RTCU Communication Hub.

The RTCU Communication Hub constitutes a back-bone in the communication between the RTCU devices and the back-end applications. The product ensures reliable and economical communication in any environment and application. The RTCU Communication Hub also supports the RTCU Deployment Server. Please refer to the Users Manual for the RTCU Communication Hub for more information.

The standard connection is equivalent to the connection type of the former RTCU Gateway 2 and works in the exact same way. This type of connection uses a standard TCP/IP connection with optional payload encryption.

The Secure connection uses the Transport Layer Security (TLS) protocol to open a connection to the RTCU Communication Hub.

The connection requires that the X509 root certificate needed to verify the server is present.

NX32L architecture devices, running firmware 1.54.00 or later, can contain two configurations. The primary server configuration can handle both secure and standard connections while the fallback configuration only supports standard connections.

If the device fails to connect to the primary server, and a fallback server configuration is present, it will switch to using the fallback server if one of the following conditions are met:

When it switches, fault code 154 is logged in the fault log (see Fault codes for further details).

When the main system fails to boot (e.g. due to an interrupted update), and the device boots into monitor mode, it will only use the fallback configuration even if a different primary server configuration is configured.

The RTCU Communication Hub is fully compatible with the former RTCU Gateway using the 'gw' API.

	•gwOpen	Opens the connection to the RTCU Gateway.
	•gwClose	Closes the connection to the RTCU Gateway.
	•gwIsOpen	Queries if connection to the RTCU Gateway is opened.
	•gwConnected	Queries if connected to the RTCU Gateway.
	•sockSetGWParm	Sets RTCU Gateway parameters.
	•sockGetGWParm	Gets RTCU Gateway parameters.
	•gwSuspend	Suspend gateway connection.
	•gwResume	Resume gateway connection.
	•gwPacketMode	Sets the mode for handling data packets.
	•gwPacketSize	Query the maximum packet size for a receiver.
	•gwReceivePacket	Receives a block of data over the RTCU Gateway.
	•gwReceivePacketDone	Releases data buffer and sends reply to sender.
	•gwSendPacket	Sends a block of data over the RTCU Gateway.
	•gwSetMedia	Changes the media used to connect to the RTCU Gateway.
	•gwGetMedia	Get the media used to connect to the RTCU Gateway.
	•gwTimeGet	Retrieves the current time from the RTCU Gateway.
	•gwEnableLPS	Controls Large Packet Support (LPS).

The 'rch' functions are only supported under the NX32L execution architecture and requires also the RTCU Communication Hub for full support.

	•rchAutoConnectGet	Queries if auto connection is enabled.
	•rchAutoConnectSet	Configure auto connection.
	•rchConfigGet	Queries the connection parameters.
	•rchConfigSet	Set the connection parameters.
	•rchFallbackGet	Queries the parameters of the fallback connection.
	•rchFallbackSet	Sets the parameters of the fallback connection.
	•rchHeartBeat	Manages the RTCU Communication Hub Heartbeat functionality.
	•rchInterfaceSet	Changes the network interface used to connect to the RTCU Communication Hub.
	•rchInterfaceGet	Get the network interface used to connect to the RTCU Communication Hub.

Autostart is a feature where the device will open a connection to the RTCU Communication Hub automatically.

If autostart is not enabled, the connection to the RTCU Communication Hub must be opened manually with the gwOpen function.

The autostart feature can be enable/disabled for the fallback configuration with the GWenable parameter in the RTCU Communication Hub configuration (sockSetGWParm / sockGetGWParm).

The autostart feature can be enable/disabled for the primary configuration with rchAutoConnectSet.

It is still possible to use gwClose and gwOpen to change the RTCU Communication Hub configuration when autostart is used.

The device will always automatically open a connection to the RTCU Communication Hub when entering recovery mode or fault mode. On NX32L architecture devices it will try all the available interfaces, starting with the currently selected interface.

Large Packet Support (LPS) supports the transmission of extended size data-packets over the RTCU Communication Hub / RTCU Gateway 2.

LPS is supported by all NX32 / NX32L architecture devices.

The standard packet-size is 480 bytes and by using LPS this is increased to 4064 bytes.
Using the gwSendPacket / gwReceivePacket functions with the larger packet-size increases the actual bandwidth over especially 3G/4G networks substantially.

RTCU IDE / RACP operations such as transfer of large files or applications to/from the device automatically take advantage of the LPS functionality when available.