RTCU Communication Hub (RCH)

 Top  Previous  Next

The RCH functions establish connectivity between RTCU devices and the RTCU Communication Hub. Functioning as a backbone between devices and back-end applications, the Hub ensures reliable and economical communication in any environment. It also supports the RTCU Deployment Server. For further details, please refer to the RTCU Communication Hub User's Manual.

Connection Types The Hub supports two connection methods:

•Standard Connection: Uses standard TCP/IP with optional payload encryption. This functions identically to the legacy RTCU Gateway 2 connection.

•Secure Connection: Uses Transport Layer Security (TLS) and requires an X.509 root certificate for server verification. (Note: Secure connections are supported on NX32L architecture devices only).

Primary and Fallback Configurations (NX32L) NX32L devices support dual server configurations:

•Primary: Supports both Secure and Standard connections.

•Fallback: Supports Standard connections only.

Failover Logic If a fallback configuration is present, the device will switch from the Primary to the Fallback server if:

•The connection fails due to a TLS error.

•Login fails 5 consecutive times.

•The connection has failed continuously for the last 12 hours.

Note: A switch to the fallback server is logged as Fault Code 154 (see Fault Codes).

Monitor Mode If the main system fails to boot (e.g., due to an interrupted update) and enters Monitor Mode, the device will exclusively use the fallback configuration, regardless of the primary settings.

 

Functions to configure the connection:

•rchAutoConnectGet

Queries if auto connection is enabled.

•rchAutoConnectSet

Configure auto connection.

•rchConfigGet

Queries the connection parameters.

•rchConfigSet

Set the connection parameters.

•rchEnableLPS

Controls Large Packet Support (LPS).

•rchFallbackGet

Queries the parameters of the fallback connection.

•rchFallbackSet

Sets the parameters of the fallback connection.

•rchHeartBeat

Manages the RTCU Communication Hub Heartbeat functionality.

•rchInterfaceGet

Get the network interface used to connect to the RTCU Communication Hub.

•rchInterfaceSet

Changes the network interface used to connect to the RTCU Communication Hub.

•rchPacketMode

Sets the mode for handling data packets.

•rchPacketSize

Query the maximum packet size for a receiver.

 

Functions to manage the connection:

•rchOpen

Opens the connection to the RTCU Communication Hub.

•rchClose

Closes the connection to the RTCU Communication Hub.

•rchSuspend

Suspends the connection to the RTCU Communication Hub.

•rchResume

Resumes the connection to the RTCU Communication Hub.

•rchConnected

Queries if connected to the RTCU Communication Hub.

•rchIsOpen

Queries if connection to the RTCU Communication Hub is opened.

 

Functions to send and receive packets:

•rchReceivePacket

Receives a block of data over the RCH.

•rchReceivePacketDone

Releases data buffer and sends reply to sender.

•rchSendPacket

Sends a block of data over the RCH.

•rchTimeGet

Retrieves the current time from the RCH.

 

 

 

Autostart

This feature manages the connection state between the device and the RTCU Communication Hub.

•Functionality: When enabled, the device automatically initiates and maintains a connection to the Communication Hub. If disabled, the connection must be manually managed using the rchOpen function.

•Flexibility: Even with Autostart enabled, it is still possible to manually cycle the connection using rchClose and rchOpen to apply configuration changes.

 

 

There are two distinct ways to control Autostart depending on the configuration type:
 

Configuration Type

Parameter / Function

Primary Configuration

rchAutoConnectSet

Fallback Configuration

rchFallbackSet

 

Regardless of the settings, the device will always force an automatic connection attempts when entering recovery or fault mode.

•NX32L Architecture: The device will cycle through all available interfaces, starting with the currently selected one, to ensure a connection is made.

 

 

 

Large Packet Support (LPS)

LPS is a protocol enhancement designed to optimize data transmission over the RTCU Communication Hub / Gateway 2.

•Compatibility: Supported by all NX32 and NX32L architecture devices.

•Default State: Enabled by default (can be toggled via rchEnableLPS).

LPS significantly increases the payload size of individual packets, which reduces overhead and improves bandwidth efficiency, particularly on 3G/4G networks.
 

Feature

Standard Packet Size

LPS Packet Size

Packet Capacity

480 bytes

4064 bytes

Practical Usage

1.Manual Data: When using rchSendPacket or rchReceivePacket, the larger packet size allows for higher throughput.

2.System Operations: RTCU M2M Studio and RACP operations (such as file transfers or application uploads) automatically detect and utilize LPS to speed up the process.