STO Instrument Control, Software Interfaces, Data Management, etc. Let's expand this block
Control Computers • Embedded systems are robust and simple solutions. 4 watt, 500 MHz ARM board: SD & USB storage, programmable FPGA, ethernet, serial, digital IO, PC/104 bus (Linux and BSD) 2 watt, 200 MHz ARM board: CF & USB storage, ethernet, serial, ADC, digital I/O, PC/104 bus (Linux and BSD) CF storage available in industrial-grade up to 16 GB, SDHC to 8 GB.
Cold-booting a TS-7200 computer at a temperature of -81oC! (In the thermal chamber at UNSW, Sydney)
Potential dual-string control system One computer manages data system, the other acts as instrument controller. Careful design of digital bus generation on the digital I/O lines and ADCs allow the two ARM computers to swap roles on-the-fly if needed. Only serial subsystems are hard-wired to a specific computer; neither is particularly critical.
Instrument & Data Mgmt. System • Items to be controlled: • Receiver subsystems (mixer bias, LO, synthesizer, etc...). (RS232, DIO and I2C/SPI interfaces) • Flip mirror (interface TBD) • Spectrometer and Data system (ethernet) • Interplay of these items with “gondola systems” • data system needs TCS header (timestamp, RA/DEC, etc.) • need synchronization with telescope for OTF • data system may need to amend observing sequence based on quality of collected data
Control Software • Each hardware component has a separate TCP/IP socket server associated with it. The server listens on that socket's port for ASCII text commands to perform. • Watchdog timers allow software and hardware to be automatically reset should they become unresponsive. • Low-level server code is written in C; client code for observing programs is written in object-based higher level languages; e.g. perl, ruby or python. • Instrument and control interfaces will be performed through a standalone GUI or a web browser. • We (C. Kulesa and C. Martin) have downloaded the SBI control code/simulator from Pietro and Harry, and are learning how the STO instrument code will dovetail into the existing SBI system. • The OTF mapping scheme, modifications to the SBI scheduler, and integration of the STO data server are the principal changes.