QB50 System Requirements Document

FIPEX on QB50 Date: 06.02.2013--- DRAFT---- Issue: 1.0.2ICD Page: 14 / 25Script TIME Field - @tTime-tagged command sequence scripts shall be uploaded to the CubeSat. The CubeSatOBC shall read the script commands and execute them at the time given by the 3-BYTE @tTIME fieldTIME is a 3-BYTE value:1 st BYTE Hours range 0-24*2 nd BYTE Mins range 0-59*3 rd BYTE Sec range 0-59*The @t TIME field is ONLY read by the OBC, but NOT sent to the SU as part of thecommand.The Science Unit shall execute commands immediately upon receipt.Time is to an accuracy of 1 sec.*Note: The SCRIPT mnemonic @NOW is encoded as time = FF:FF:FF – this shall beinterpreted by the OBC script handler to send the script command immediately.Script Encoder Software ToolAn ASCII - user-readable “Command Sequence Script” shall be encoded into a BYTE streamusing the SU_SCRIPT_ENCODER software tool.As an example, the script commands:OBC_SU_ON @19:00SU_HK 41 @19:04Would be encoded into the following BYTE stream by the SU_SCRIPT_ENCODER tool:0x0F, 0x13, 0x00, 0x00, 0x0B, 0x01, 0x29, 0x13, 0x04, 0x00The SU_SCRIPT_ENCODER shall parse the ASCII script for parameter range errors, andlogical errors.Name:ILR-RFS_FPXQB50_ICD_1000