Use of open channel communication in automatic generation control (AGC) of interconnected power systems leads to time delay in the secondary frequency control loop. Such time delayed AGC of a power system can lead to unstable operation. This paper presents an insight on how gain tuning approaches need to be changed from single objective to multi objective in order to achieve stable operation as well as fast frequency and tie power regulation. The analysis is performed on a single area hydro power system. The effect of secondary controller gains on conventional gain tuning objective function, integral squared error (ISE), and on the communication delay margin has been shown in this work. The paper concludes that while a particular set of proportional integral (PI) secondary controller gain can give least ISE value; the same can give rise to stability issues due to reduction in delay margin. It is discussed that a tradeoff is needed between improvement in ISE and improvement in delay margin. Thus, the paper proposes to use multi objective optimization for PI controller gains where one objective is to minimize the ISE while the other is to maximize the delay margin. © 2017 IEEE.