Temperature Controller - Staveb AG

5-34 Parameter Functions and DefinitionsRelated Parameters• Alarm Value 1 (p. 5-6), Upper-Limit Alarm Value 1, Lower-Limit AlarmValue 1 (p. 5-7) (Operation function group)• Alarm 1 Type (Initial Setting function group) (p. 5-26)• Alarm 1 Open in Alarm (p. 5-32), Standby Sequence Reset Method(p. 5-31), Alarm 1 Latch (p. 5-38) (Advanced Setting function group)ST (Self-Tuning) Stable RangeConditions of Use: Control must be configured for a temperature input,standard control mode, PID control method, and self-tuning (ST) set to ON.Function: This parameter allows you to configure the value for determiningthe conditions under which ST (self-tuning) occurs. This parameter cannot beused when the Self-Tuning (ST) parameter is set to OFF.Table 5.AIConfigurable Range Units Default Value0.1…999.9 °C or °F 15.0Related Parameters• PID/ON/OFF (Initial Setting function group) (p. 5-22)• Input Type (Initial Setting function group) (p. 5-20)• ST (Initial Setting function group) (p. 5-23)Table 5.AJAt Start of Program Execution(Self-Tuning ON)1. The set point at the start of programexecution differs from the set point (seeNote 1 below) when the previous SRTwas executed.2. The difference between the controlledtemperature at start of programexecution is larger than the currentproportional band (1.27+4°C) or the STstable range, whichever is larger.3. The controlled temperature at the startof program execution is smaller than theset point during reverse operation, and islarger than the set point during directoperation.4. No reset from input errorWhen Set Point is Changed(Self-Tuning ON)1. The new set point differs from the setpoint (see Note 1 below) used when theprevious SRT was executed.2. The set point change width is larger thanthe current proportional band1.27+4°C orthe ST stable range whichever is larger.3. During reverse operation, the new setpoint is larger than the set point beforethe change; and during direct operation,the new set point is smaller than the setpoint before the change.4. The temperature is in a stable state (seeNote 2 below). (An equilibrium state [seeNote 3 below] is acceptable when theoutput is 0% when the power is turnedON.)Note 1: The previous SRT-implemented set point is called the set pointobtained by calculating the PID constant by the previous SRT.Publication 900-UM003C-EN-E - January 2004