Learn Farsi: چنانچه چراغ ثابت شد، آی‌پی را در تنظیمات وارد کنید. - In the event that the light became steady, enter the IP in the settings.

When using conditional words like chenânche (in the event that) or agar (if) to talk about a future event, Farsi often uses the Simple Past instead of the Present Subjunctive. Using the Simple Past emphasizes that the condition must be entirely completed before the main action can take place. You can think of chenânche ... shod as meaning "once it has successfully become...".

Could I just use agar (if) instead of chenânche in this sentence?

Grammatically, yes. However, chenânche is noticeably more formal and carries the nuance of "in the event that" or "should this happen." Because of this, it is highly common in instruction manuals, official guidelines, and technical setups like this one, while agar is preferred in everyday speech.

What does sâbet mean here, and is it only used for lights?

sâbet generally means fixed, constant, stationary, or proven. In the context of electronics, sâbet shodan (to become fixed) is the standard and natural way to express that a blinking indicator light has stopped flashing and "gone solid" or "become steady."

Why does the word tanzimât (settings) end in -ât rather than a standard Farsi plural like -hâ?

tanzimât uses the Arabic plural suffix -ât. Farsi has borrowed many words from Arabic, and they frequently retain this Arabic plural ending, especially in formal, administrative, or technical vocabulary. The singular noun is (setting, adjustment, or arrangement).