Hi there! If your HW-A450 Soundbar and Samsung TV are connected by an optical cable, Auto Power Link will turn your soundbar on automatically when you turn on the TV. If you have the soundbar connected with an HDMI cable to the Samsung TV, Anynet+ will turn the soundbar on automatically.
For further details, please see this article: https://www.samsung.com/us/support/answer/ANS00062384/
Should you need further assistance, please contact Samsung Customer Support at 1-800-SAMSUNG. ^Gina