What is in a Functional Block Diagram? A function block diagram describes a function between inputs and outputs and should describe the system in one picture. What should it include –Show All major system components –Interfaces to the outside world –Interfaces between subsystems –Clearly identify power, data, and structural interfaces –Should answer how the mission statement is met –Easy to read

Pick and Choose The following are FBD for progressively more complex systems. All contain strengths and weaknesses in conveying system level information. Pick ideas which would work well in describing your project. The Final FBD is a poor example due to it’s complexity for this application. Use this as an example of what not to do as it is too hard to read.

Thermal Temp Sensors Coatings, Insulation Heaters Instrument CCD Star Imaging System Small FOV CCD Imager FOV ~10° Command and Data Handling EDAC 516ConnectorHASP Power27-32Vat <2.5AAnalog,Discreet Signals Power ActivationSwitch Wide FOV CCD Imager 12V Converter 3.3V Converter 5V Converter Data Storage Hard Disk Drive Micro Computer FOV ~150° HASP SerialDB9 Connector Stabilization and Attitude Accelerometers Magnetometer Gyroscopes Data Power Instrument Sky Brightness Photometers Fixed Photometer 1 Fixed Photometer 2 Fixed Photometer 3 Filter Wheel Photometer Filter Wheel Motor Each FOV ~10°

5 Functional Block Diagram ACC Control Acc THM Control Coatings, Insulation Sensors Instrument NMS Control Instrument FOV 32° x 1° Instrument FOV 32° x 1° CDH I 2 C I/O CPU AVR32 RAM TBD SSD TBD RTC SFT OS Scheduling Comm ADCS Science Serial I/O Wiring Harness SEP Mech1 Mech2 Control Lightband assy. ABS EPS Photovoltaics 30W Battery B 14.4V 4AH RegulationControl FOV 360° Inhibit x4 Battery A 14.4V 4AH LV electrical interface Satellite Sep Plane (SSP) COM Tx Ant Rx Ant FOV 90° Tx 70cm 38.4kbps Rx 2m 9.6kbps TNC ACC Control Acc ADC Control Horizon Crossing Sensor Torque rod A Horizon Crossing Sensor Torque rod A Mag (3- axis) FOV 2° Instrument NMS Control Instrument FOV 32° x 1° Instrument FOV 32° x 1° ADC Control Horizon Crossing Sensor Torque rod A Horizon Crossing Sensor Torque rod A Mag (3- axis) FOV 2° THM Control Coatings, Insulation Sensors CDH I 2 C I/O CPU AVR32 RAM TBD SSD TBD RTC SFT OS Scheduling Comm ADCS Science Serial I/O EPS Photovoltaics 30W Battery B 14.4V 4AH RegulationControl FOV 360° Inhibit x4 Battery A 14.4V 4AH LV electrical interface Satellite Sep Plane (SSP) COM Tx Ant Rx Ant FOV 90° Tx 70cm 38.4kbps Rx 2m 9.6kbps TNC SEP Mech1 Mech2 Control Lightband assy. ABS

Bad Example