Alarm handling

Overview of the Plastics Processing Framework alarms

The following alarm conditions are continuously monitored by the temperature controller:

• Absolute temperatures (high and low):
• the actual temperature is below aaaPfwTempMparamFromHmi[...].AbsoluteLow, the global flag aaaTempAlarm_AbsoluteLow is set to TRUE. As soon as the actual temperature exceeds the threshold, aaaTempAlarm_AbsoluteLow becomes FALSE again.
• if the actual temperature is above aaaPfwTempMparamFromHmi[...].AbsoluteHigh, the global flag aaaTempAlarm_AbsoluteHigh is set to TRUE. As soon as the actual temperature falls below the threshold, aaaTempAlarm_AbsoluteHigh becomes FALSE again. As soon as aaaTempAlarm_AbsoluteHigh is active, the corresponding zone is switched off. After falling below the limit, the zone returns to regulated operation.
• Relative temperatures (in two bands around the setpoint):
• if the actual temperature is below aaaPfwTempPparamFromHmi[...].Threshold_MM, the global flag aaaTempAlarm_LowLow is set to TRUE. As soon as the actual temperature exceeds the threshold, aaaTempAlarm_LowLow becomes FALSE again.
• if the actual temperature is below aaaPfwTempPparamFromHmi[...].Threshold_M, the global flag aaaTempAlarm_Low is set to TRUE. As soon as the actual temperature exceeds the threshold, aaaTempAlarm_Low becomes FALSE again.
• if the actual temperature is above aaaPfwTempPparamFromHmi[...].Threshold_PP, the global flag aaaTempAlarm_HighHigh is set to TRUE. As soon as the actual temperature falls below the threshold, aaaTempAlarm_HighHigh becomes FALSE again.
• if the actual temperature is above aaaPfwTempPparamFromHmi[...].Threshold_P, the global flag aaaTempAlarm_High is set to TRUE. As soon as the actual temperature falls below the threshold, aaaTempAlarm_High becomes FALSE again.
• If the constant cnst_pfw_selRelAlarm is TRUE, the relative alarms refer to the entered set temperature, otherwise to the internally ramped set temperature.



• Error messages from the terminal:
• Are passed on via ST_TcPfw_TempToHmi_Itf[...].Error and ST_TcPfw_TempToHmi_Itf[...].ErrorId.
• The associated zone is then switched off.
• By activating the error heating in the machine parameters, the zone is further kept at temperature.
• Error messages during autotune:
• Are passed on via ST_TcPfw_TempToHmi_Itf[...].Error and ST_TcPfw_TempToHmi_Itf[...].ErrorId.
• Misbehavior during heating:
• If the actual value of a zone does not react to the setpoint change during heating up, an error is output and the zone switches off.