1. 6/22/04Kickoff LAT Scenario Meeting1 What’s a Mnemonic? mne·mon·ic (ni-'mä-nik) adj. Relating to, assisting, or intended to assist the memory. n. A device, such as a formula or rhyme, used as an aid in remembering. [Greek mnēmonikos, from mnēmōn, mnēmon-, mindful.] The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2000 by Houghton Mifflin Company.

2. 6/22/04Kickoff LAT Scenario Meeting2 Command Mnemonics Describe an activity Fixed and fully defined in the database Example: LHKLIMITCHECK ON or, LHKLIMITCHECKON LHKLIMITCHECKOFF CMDMNEMONIC FIELD=VALUE where: CMDMNEMONIC – name of the command mnemonic, as specified in the database FIELD – name of a field (parameter or submnemonic) for CMDMNEMONIC, as specified in the database VALUE – value for field. Either an expression or the name of a discrete value for field, as specified in the database. “field=value” may be shortened to “value” when value is a discrete value and only one of cmdmnemonic's fields uses that discrete value.

3. 6/22/04Kickoff LAT Scenario Meeting3 Command Mnemonic Parameters Parameters (fields) further define the action of the commands –May be fixed, variable, or invisible Fixed parameters may only take on fixed values which are predetermined and defined in the database (eg. ON, OFF) Variable parameters may take on any value within a specified range of values (eg. ADDRESS=h'7FF') Invisible parameters are fixed parameters that can only take on one predefined value –Example: TBLESELECT TABLEID=145, SRCZERO, DESTRAM

4. 6/22/04Kickoff LAT Scenario Meeting4 How the ISOC Commands the LAT

5. 6/22/04Kickoff LAT Scenario Meeting5 ITOS and the Database Database contains the descriptions that enable the ITOS command subsystem to construct binary spacecraft commands from mnemonic commands entered through System Test and Operations Language (STOL) Database contains the descriptions that enable the telemetry subsystem to unpack spacecraft telemetry values from the telemetry stream –Links values to names (mnemonics), which can be referenced in STOL or ITOS displays, along with limits and conversions for each value