Keithley Instruments Inc. designed its autotuning thermoelectrically cooled (TEC) SourceMeter for test and control of TECs used in telecom laser diode modules. The model 2510-AT controls laser diode wavelength and light intensity output, and allows short setup times and high production throughput. This GPIB-controlled instrument automatically optimizes PID coefficients of the temperature control loop and facilitates integration with other devices in a light-intensity/current/voltage test stand. The two available modes of autotuning are minimum overshoot and minimum settling time. The device provides a maximum output of 50 W.