| Application (App) |
A set of data and functions that is treated as a single entity by the cFE. |
| Application ID |
A processor unique reference to an Application. |
| Application Programming Interface (API) |
A set of routines, protocols, and tools for building software applications. |
| Board Support Package (BSP) |
A collection of user-provided facilities that interface an OS and the cFE with a specific hardware platform. The BSP is responsible for hardware initialization. |
| Child Task |
A separate thread of execution that is spawned by an Application’s Main Task. |
| Command |
A SB Message defined by the receiving Application. Commands can originate from other onboard Applications or from the ground. |
| Core Flight Executive (cFE) |
A runtime environment and a set of services for hosting FSW Applications. |
| Critical Data Store |
A collection of data that is not modified by the OS or cFE following a Processor Reset. |
| Cyclic Redundancy Check |
A polynomial based method for checking that a data set has remained unchanged from one time period to another. |
| Developer |
Anyone who is coding a cFE Application. |
| Event Data |
Data describing an Event that is supplied to the cFE Event Service. The cFE includes this data in an Event Message. |
| Event Filter |
A numeric value (bit mask) used to determine how frequently to output an application Event Message defined by its Event ID (see definition of Event ID below). |
| Event Format Mode |
Defines the Event Message Format downlink option: short or long. |
| Event ID |
A numeric literal used to uniquely name an Application event. |
| Event Message |
A data item used to notify the user and/or an external Application of a significant event. |
| Event Message Counter |
A count of the number of times a particular Event Message has been generated since a Reset or since the counter was cleared via a Command. |
| Event Message Port |
A display device that is used to display Event Messages in a test environment. |
| Event Type |
A classification of an Event Message. |
| FIFO |
First In First Out - A storage device that implies the first entry in is the first entry out. |
| Hardware Platform |
The target hardware that hosts the FSW. |
| Interface Control Document |
A document that describes the software interface, in detail, to another piece of software or hardware. |
| I/O Data |
Any data being written to and/or read from an I/O (input/output) port. |
| Local Event Log |
An optional Critical Data Store containing Event Messages that are generated on the same processor on which it resides. |
| Log |
A collection of data that an application stores that provides information to diagnose and debug FSW problems. |
| Main Task |
The thread of execution that is started by the cFE when an Application is started. |
| Memory Data |
Any data being written to and read from memory. No structure is placed on the data and no distinction as to the type of memory is made. |
| Message ID |
An identifier that uniquely defines an SB message. |
| Mission |
A particular implementation of cFE FSW for a specific satellite or set of satellites. |
| Memory Management Unit |
A piece of hardware that manages virtual memory systems. |
| MsgId-to-Pipe Limit |
The maximum number of messages of a particular Message ID allowed on a Pipe at any time. |
| Network |
A connection between subsystems used for communication purposes. |
| Network Queue |
A device that stores messages and controls the flow of SB Messages across a Network. |
| Operational Interface |
The Command and Telemetry interface used to manage the cFE and/or Applications. |
| Operator |
Anyone who is commanding the FSW and receiving the FSW telemetry. |
| Pipe |
A FIFO device that is used by Application’s to receive SB Messages. |
| Pipe Depth |
The numbers of SB Messages a Pipe is capable of storing. |
| Pipe Overflow |
An error that occurs when an attempt is made to write to a Pipe that is completely full of SB Messages. |
| Platform |
See “Hardware Platform” above. |
| Processor Reset |
The processor resets via the execution of its reset instruction, assertion of its reset pin, or a watchdog timeout. |
| Power-on Reset |
The processor initializes from a no-power state to a power-on state. |
| Quality of Service (QoS) |
Quality of Service has 2 components, Priority and Reliability. |
| Request |
The act of an Application invoking a cFE service that resides on the same processor as the Application. |
| Routing Information |
Any information required to route SB Messages locally or remotely. |
| Software Bus |
An inter-Application message-based communications system. |
| SB Message |
A message that is sent or received on the software bus. |
| Subscribe |
The act of requesting future instances of an SB Message to be sent on a particular Pipe. |
| System Log |
Special “Event Message” log for events that occur when the Event Services are not available. |
| Telemetry |
A SB Message defined by the sending Application that contains information regarding the state of the Application. |
| Unsubscribe |
To request that an SB Message no longer be routed to a particular Pipe. |
| User |
Anyone who interacts with the cFE in its operational state. |