NY -- Standard&Poor's CreditWire 9/17/96 -- Standard&Poor's today has assigned its single-`B'-minus rating to Protection One Alarm Monitoring, Inc.'s $90 million 6.75% convertible senior subordinated notes due 2003. Also, Standard&Poor's has affirmed its single-`B'-plus corporate credit rating and single-`B'-minus subordinated debt rating of the company. The rating reflects the risks inherent in Protection One's high-growth strategy, its short operating history, thin interest coverage, and limited financial flexibility. Offsetting these factors are the company's stable and high-margin recurring revenue base, and good cash flow generation. With fiscal 1995 revenues of about $56 million, Culver City, Calif.- based Protection One focuses on the residential segment of the highly fragmented and consolidating security services industry, targeting the