  The LLRF of five of TRIUMF's ISAC-1 accelerator cavities have been replaced
by 3 similar FPGA based system with different operating frequencies. These LLRF
use internal digital phase locked loops for frequency generation and
synchronization, feedback control using Amplitude/Phase regulations. These
FPGAs also have internal stepper motor controller for resonance control.
Various modes of resonance control are possible, including phase comparison and
minimum seeking slide-mode control. Operational performances including
frequency generation and synchronization, amplitude and phase noises, tuning
speeds, compatibility to original remote controls, are reported.
