Oven controller design documents Martijn Jasperse February 2011

State diagram Black arrowsAutomatic Green arrowsUser presses “start” Blue arrowsUser presses “stop” Purple arrowsInput value condition Red arrowsError condition Passive: Monitoring and communication only Cooling: Peltier control active, oven disabled Cooking: Both oven and peltier under active control Active: Only state for which gate valve is opened Upon leaving state gate valve must shut #SOFTERR Power on #COOLPTR #WARMPTR #WAITING #COLD #WMPTRLP #AUTO #CLPTRLP #HEATOVN #COOLOVN #CLOVNLP #HTOVNLP #ACTIVE #READY #SOFTERR #MANUAL

Failsafe procedure #RUNCHK MUST be called at the BEGINNING of each state (and within loops) #FAIL Check vacuum gauge inputs Check thermocouple alarms Check thermistor voltages Calculate, check pressure Calculate temperatures Check oven temperature Check peltier temperature Check for “start”/”stop” Siren Call #DISABLE #FAILED Sanity check inputs to ensure monitors connected, functioning Compute meaningful values, ensure system is behaving Check PID control loops operating properly (if activated) Harsh fail #SOFTERR Bleep Call #DISABLE #WAITING #COLD #SOFTLP Check for override Failsafe state Must manual override/reboot Soft fail Peltiers still running and operational Peltiers not running or problematic #MANUAL GV, oven disabled, peltiers enabled by switch #WAITING Switches off and system safe

Lab equipment... BNCs Amplifiers/dividersAnalog inputs Registers Processing (failsafe program) Watchdog timer LabView monitor GalilLogger DR output Galil RIO State change Keep-alive Analog Processing LCD screen Controller Box SysLog UDP SysLog External devices Communications schematic BEC server