The disturbance suppression function (DSF) works in conjunction with the PID control to suppress temperature drops caused by routine and anticipated disturbances in applications like: ■ Deposition equipment where the chamber temperature falls when gas is injected or material is added or removed through an open door ■ Wafer probers when current is applied to the wafer, resulting in an increase in temperature ■ Molding systems where the mold temperature drops when resin is injected DSF automatically suppresses positive and negative temperature excursions caused by foreseeable events. DSF is initiated by trigger signals prior to the disturbance and adds to or subtracts from the MV. This autotuning adjusts the feed forward (FF) MV, FF operation time, and FF waiting time and can shorten the time for achieving temperature stabilization by up to 80 percent (Figure 5). NX-TC units like the 2-channel NX-TC2405 designed for driving SSRs are optimized for scalability. Designers can use Omron’s Sysmac studio for programming control of multiple heating circuits or locations when implementing multistage heating/cooling processes.
Adaptive PID for disruption suppression The NX-TC Adaptive Temperature Controllers take PID control to the next level and can adapt to real-time operating conditions. Adaptive control enables self- optimization of control settings due to process changes. In addition, these controllers include built-in functions for packaging sealing applications and water- cooled plastic extruders. For simple applications, basic on/off control can be implemented.
Figure 4: E5CC temperature controllers clearly display PV and SV values. (Image source: DigiKey)
Figure 5: DSF-enhanced PID control can reduce the wait time for temperature stabilization by up to 80 percent. (Image source: Omron)
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