Solar Probe Plus FIELDS MAG Peter Harvey

MAG FSW Requirements

Initialization Initialization of MAG 1.DCB configures MAG – Outboard. System clock and MAG heater clock Stored on DCB for DFB 1. RAM - MAG Telemetry Buffers MAG data in DCB SRAM

Power Up Time Interval Required -MAG FPGA has a temperature dependent power-on requirement -The unpowered time must be greater than curve below (table 1) -MEP minimum functional temp is -25C -Implementation: 1. Use DCB Temp (proxy for MAG) to set initial wait time N 2. Wait N minutes 3. Power on MAG 4. Send MAG Reset 5. If no MAG telemetry after 10 cycles, i.Power off MAG ii.N= N+5 minutes iii.Go to step 2 Initialization

Processing Reset MAG when commanded from ground Generate MAG Sample Telemetry from MAG raw samples - by averaging 2**N raw samples together (1 to 32). - Averages are done separately for X,Y,Z axes; - X,Y,Z samples shall be included in the same packet Diagnostic Messages copied to ground for comparison Processing

Processing (on TDS) Generate a MAG vector and provide to SWEAP - once per second; - as the average of the raw measurements from the MAG sensor at the end of previous second, minus an offset vector uplinked from the ground; - using separate offset vectors for each range setting; - as detailed in the FIELDS to SWEAP ICD Processing

Mag Parameter Table

APID 2F0 : MAG Sample Telemetry. APID 2A8 : MAG Housekeeping Telemetry APID 2B0 : MAG Diagnostic (Message wrapper). Data Products

APID 2F0 MAG Survey Data Average 2^N pts 2-bit Range/cycle 16 cycle max Packed Range bits

APID 2F0 MAG Survey Data (2 of 2) Default 32 Hz* Averages 8 pts At Lower Rates, packet shrinks Always multiple of 32 vectors (compatible with standard compressor).

APID 2A8 MAGo HSK (1 of 2 )

APID 2A8 MAGo HSK (2 of 2 )

APID 2B0 DIAGNOSTICs Any Message can be routed with an APID wrapper Message must be < = 4084 bytes

Issues  MAG ETU is working great. No issues there.  MAG Shared Data to the S/C is not defined Issues