The Model 849TA AC Power Controller is a frequency, amplitude and phase controller designed to plug into all California Instruments1 T Series AC power sources. The frequency, amplitude and phase of the power source output may be locally controlled using a keyboard on the front of the controller, or remotely controlled through its IEEE-488 interface. The controller output is a variable frequency, variable amplitude, variable phase AC voltage. It provides the three- phase input signal for the associated power source where it is amplified to produce the high-power, multi-phase output. Sense inputs for each of the three phases assures that the voltage at the remote sense point equals the programmed value. If the programmed voltage value cannot be maintained within specified limits, the controller reduces the power source output then displays an error message on its control panel. The displayed message indicates which of the phases has not been maintained at the programmed value. Microprocessor-controlled, digital logic is employed in the controller for frequency generation. Its sine wave outputs are produced by a precision digital-to-analog converter. Frequency accuracy is maintained by a quartz crystal whose temperature stability is ±5 parts per million per degree celsius. The Model 849TA AC- Power Controller provides many features. These features include: - High-reliability CMOS design uses less than 2 watts of power. - More than 20 programmable functions. - Multi-page menu screen and 17 parameter screens for total system programming and monitoring. - Independent control of amplitude, phase angle, frequency, voltage range and current limit on multi-phase systems. Master/Slave configurations for applications requiring more than 3 phases. 4 decades of frequency output with resolution to G.01 Hz. Automatic frequency range changing. Amplitude, frequency, phase angle and current limit may be ramped incrementally via program control.Start, finish, step size and step duration are independently programmable. Sine or square wave output independently selectable on each phase. Programmable voltage ranges. Simple IEEE-488 software using Abbreviated Plain English (APE). Alphanumeric prompting display is user-friendly; no reference codes are required. 3.2 character alphanumeric display. 2 0 key keypad for complete front panel control. Complete programming (including IEEE-488 bus address and calibration from the front panel) - no inside adjustments are needed. Non-volatile memory for instant set-up to pre-programmed test parameters. Non-volatile and volatile registers for storage of programmable parameters. System diagnostics with error messages on front panel display. Internal clock tracks total elapsed time. Internal counter tracks the frequency of an external signal from 45 Hz to 450 Hz to provide a low distortion output.