TEC PID Tuning Migration
TEC PID tuning changes when migrating Koheron controllers from V0.x to V1 firmware.Koheron products currently ship with firmware V0.x by default. Firmware V1 is under active development and is not publicly available yet.
Contact us if you would like early access or want to evaluate V1 firmware on your device.
TEC PID tuning migration
Firmware V1 removes the pgain, igain, and dgain TEC PID tuning commands. Use kprop, tint, and tder for PID tuning.
The TEC PID error is consistently expressed in °C. On voltage-output products, kprop is expressed in V/°C. On HTC200, kprop is expressed in A/°C.
CTL200 and CTL300E users may need to retune the TEC loop because earlier firmware used legacy board-specific PID error units.
There is no direct command-by-command conversion from the V0.x pgain, igain, and dgain values to the V1 parameters. In V0.x, the error scaling and gain definitions varied by product; igain and dgain were discrete coefficients, not integral and derivative time constants. A valid V1 retuning depends on the product, thermistor calibration, sampling behavior, thermal load, and operating point.
In V1, kprop is the proportional response to temperature error, while tint and tder express integral and derivative time constants. kprop is expressed in V/°C on voltage-output products and A/°C on HTC200; tint and tder are expressed in seconds. Do not copy V0.x numeric values into these parameters. Start from the product defaults or a known safe baseline, then retune and validate the loop.
Temperature-stability tolerance now uses ttol in °C on all supported boards. V0.x CTL200 and HTC200 used a resistance-based stability tolerance in Ω; V0.x CTL300E did not provide an equivalent stability-tolerance command. The default ttol is 0.01 °C.