PIDMaxwell MPU90 ramp and soak PID profile multile steps controller is a touch key temperature controller, the process value changed based on predetermined ramping rate and soak rate. process value changes based on a curve over time, the output can be Relay to drive an AC contrator, or SSR Drive to drive an external solid state relay, or 4-20mA analog outputs, the setting keys on the panel is touch key with a responsive sound, it is not a conventional setting key where it goes down a little bit when you push it, it's a touch key which makes it very durable. high sampling rate and RS-485 optional.