Station ID is every hour. Also you have to say it in a very specific format: Call letters, city; or call letters, frequency, city. No additional words in between: “WKRP in Cincinnati” would be invalid.
TV stations are allowed to do it visually. When I was young it was common to see it as a full screen ID in between shows (often with a quick weather report, “time and temperature”). Later most stations I saw quit that and just put it as a bug at the bottom of the screen over top of the show.