User's Manual
PMAC2 User Manual
34 Setting Up PMAC2 for Sine-Wave Output Control
Supplemental Flags
The Acc-8E can accept hall-effect signals for power-on phase information through its supplemental flag
connector on the U, V, and W flags.
Other Signals
The Acc-8E has AC Opto isolator inputs for overtravel limit, home, and user flag inputs.
PMAC2 Parameter Setup
Parameters to Set Up Global Hardware Signals
Several parameter that set up global and multi-channel hardware operation must be set for proper
operation of the analog sine-wave commutation mode. These variables are in the I900 to I909 range.
Phase Clock Frequency Control: I900, I901
Every phase clock cycle, PMAC2 performs the commutation for motors that have been configured for
these algorithms. I900 and I901 together determine the phase clock frequency. Typically, the phase clock
frequency is in the range of 8 kHz to 12 kHz. The 60 MHz PMAC2 is capable of performing
commutation for eight axes at up to 12 kHz. The 40 MHz is capable of doing this for eight axes at up to 9
kHz, or for six axes at up to 12 kHz. The default values for I900 and I901 produce a phase clock
frequency of 9.03 kHz; this is suitable for almost all applications.
I900 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.
To generate any PWM signals on Channels 1-4, refer to the Using PMAC2 for Direct PWM Control
section for details and use I901 to select how the PHASE clock is derived from MaxPhase.
If PWM signals on channels 1-4 are not needed, set I900 to make the MaxPhase clock frequency equal to
the PHASE clock frequency wanted. Use the following formula:
I
kHz
MaxPhaseFreq kHz
900
117 8
2
1=−
int
,964.
*()
I901 determines how the actual phase clock is generated from the MaxPhase clock, using the equation:
1901I
)kHz(eqMaxPhaseFr
)kHz(PhaseFreq
+
=
I901 is an integer value with a range of 0 to 15, permitting a division range of 1 to 16. If the MaxPhase
frequency has been set to equal the desired phase clock frequency, make I901 equal to 0 for the divide-
by-1 setting.
Servo Clock Frequency Control: I902
I902 determines how the SERVO clock is generated from the PHASE clock, using the equation
1902I
)kHz(PhaseFreq
)kHz(ServoFreq
+
=
I902 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, PMAC2 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 by PMAC2. Typical servo clock frequencies are 1 to 4 kHz.
I10 tells the PMAC2 interpolation routines how much time there is between servo clock cycles. It must
be changed any time I900, I901, or I902 is changed. I10 can be set according to the formula:
()()()
1902I1901I3900I*2
9
640
10I +++=