A method of using toner concentration (TC) as an active actuator in the
tonal reproduction curve (TRC) controller, so that not only will the TRC
controller maintain the TRC of the output, but also all the electrostatic
actuators will not diverge, and the toner concentration will be within
the latitude range of the xerographic system. The process ensures that
the target of the toner concentration (TC) sensor will be changed
properly in direction (up/down) and amplitude to compensate the TRC
output of the print engine based on either reflective reactance readings
and/or the level of the electrostatic actuators.