I guess this thread will now serve to document the process to use a Sigma V servo rotary table with an older generation Haas controller. Option A will require a little bit of work, but is doable. Assuming I can find enough *free* time between now and the end of the year I am hopeful to have this working soon.
maximum frequency calculation (A & B phases) :
pulses/turn = 1,048,576
ratio = 80:1
pulses/360* = 83,886,080
maximum speed = 300*/SEC = 50 RPM
pulses/sec = 83,886,080 x 300* / 360* = 69,905,066.67 Hz ~ 70 MHz
need at least 4x overhead = 70 MHz * 4 = 280 MHz ==> 500 MHz
We will use a 500 MHz FPGA to divide the 1,048,576 pulses/turn down to 65,536 pulses/turn @ 300*/SEC without loss of pulse count when changing directions.
As a first approximation I may use a 200 MHz PIC since I don’t require 50 RPM indexing speed. At 15 RPM this requires ~ 21 MHz speed which should be enough for my immediate needs. The PIC will have significantly more overhead than the FPGA so I will shoot for a 10:1 ratio.
An alternate first approximation would be to use multiple shift registers running at 100 MHz along with several flip flops to determine direction and change in direction to keep the counts correct.
I am aware of existing products from Motrona and others but these have very limited input capabilities (~ 1 MHz).