Barchu, then Minchah?

Hi,

One who comes to shul in the evening and finds the minyan beginning an early maariv with Barchu may respond and then daven minchah afterward, if this is a weekday. However, one may not do so on Friday night, as he will have accepted Shabbat by responding to Barchu.

(Rivivot Ephraim 1:172)

Have a great day,
Mordechai