The present invention provides systems and methods to convert a reconfigurable optical node multiple-input multiple-output (MIMO) system to a single-input single-output (SISO) system suitable for a proportional-integral-differential (PID) control process. Advantageously, the present invention allows PID control to apply to a MIMO optical node by modeling the node as two SISO systems. The present invention optimizes the division of gain and loss between components in the reconfigurable optical node. This provides means to control the net gain and loss of a series of components when the component chain being controlled includes those components that have a single action affecting multiple channels and components that affect only one channel. The present invention utilizes control of a single quantity of amplifier gain minus attenuation for each channel, and the coupling together of all channels in the amplifier which makes the channels inter-dependent.