Delta Tau 5xx-603869-xUxx - Manual (Page 35)

Brick Motion Controller Hardware Reference Manual
System Wiring 27
etc.), then writing values to the M-variable. The analog outputs are intended to drive high-impedance
inputs with no significant current draw. The 220
Ω output resistors will keep the current draw lower than
50 mA in all cases and prevent damage to the output circuitry, but any current draw above 10 mA can
result in noticeable signal distortion.
The following I-variables must be set properly to use the digital-to-analog (filtered DAC) outputs:
I7000 = 1001 ; PWM frequency 29.4kHz, PWM 1-4
I7001 = 5 ; Phase Clock 9.8kHz
I7002 = 3 ; Servo frequency 2.45kHz
I7003 = 1746 ; ADC frequency
I7100 = 1001 ; PWM frequency 29.4kHz, PWM 5-8
I7103 = 1746 ; ADC frequency
I70n6 = 0 ; Output mode: PWM
Ixx69 = 1001 ; DAC limit 10Vdc
I10 = 3421867 ; Servo interrupt time
n = channel number from 1 to 8
xx = motor number from 1 to 8
Parameters to Set up Global Hardware Signals
I7000 determines the frequency of the MaxPhase clock signal from which the actual phase clock
signal is derived. It also determines the PWM cycle frequency for Channels 1 to 4. This variable
is set according to the equation:
I7000 = INT[117,964.8/(4*PWMFreq(KHz)) - 1]
The Clipper Board filtered PWM circuits were optimized for about 30KHz. The minimum
frequency I7000 should be set to is 1088 (calculated as 27.06856KHz)
I7001 determines how the actual phase clock is generated from the MaxPhase clock, using the
equation:
PhaseFreq(kHz) = MaxPhaseFreq(kHz)/(I7001+1)
I7001 is an integer value with a range of 0 to 15, permitting a division range of 1 to 16. Typically,
the phase clock frequency is in the range of 8 kHz to 12 kHz. About 9 KHz is standard, set I7001
= 5.
I7002 determines how the servo clock is generated from the phase clock, using the equation:
ServoFreq(KHz) = PhaseFreq(KHz)/(I7002+1)
I7002 is an integer value with a range of 0 to 15, permitting a division range of 1 to 16. On the
servo update, which occurs once per servo clock cycle, PMAC updates commanded position
(interpolates) and closes the position/velocity servo loop for all active motors, whether or not
commutation and/or a digital current loop is closed. Typical servo clock frequencies are 1 to 4
kHz. The PMAC standard is about 2 KHz, set I902 = 3.
I10 tells the Clipper Board interpolation routines how much time there is between servo clock
cycles. It must be changed any time I7000, I7001, or I7002 is changed. I10 can be set according
to the formula:
I10 = (2*I7000+3)(I7001+1)(I7002+1)*640/9
I10 should be set to 3421867.
I7003 determines the frequency of four hardware clock signals used for machine interface channels 1-4;
This can be left at the default value (I7003=*) unless the on board Option-12 ADCs are used. The four