If you are talking about making the links,you are into a colder smoking,cooling,etc process and the sausage pros will have to jump in.
If they are already cooked,you need to get them up to about 145� and the skin will glisten nicely.
Depending on the amount of smoke you desire,you can cook from 180�-225� for +/-60 mins.
If they are raw,like Johnsonville, and we are just cooking them,we cook at about 225� ,until they reach an internal of about 157�.
We like to cook ours between categories,or whenever guests arrive.
That gives folks something to snack on,while having a cold drink.
We put out some chopped japs,mustard,some chopped red onions,and rolls.