1. Txais yuav PLC thiab kov npo, yooj yim rau kev khiav lag luam. 2. Siv ob txoj siv rub nrog servo ua rau zaj duab xis thauj khoom du.
3. Lub tswb zoo meej
system kom daws tau qhov teeb meem sai sai.
4. Ua haujlwm nrog lub tshuab ntsuas qhov hnyav thiab sau, Txheej txheem ntawm kev ntsuas qhov hnyav, hnab ntim khoom, sau,
hnub luam ntawv, them (exhausting), suav thiab xa cov khoom tiav tuaj yeem ua tiav tau.