Reference Manual

16-Axis MACRO CPU Software Reference Manual
16-Axis MACRO Station MI-Variable Reference 33
MS{anynode}, M210 – MI225 Servo IC Identification Variables
Range: 0
Units: Modified 16-Axis MACRO Station Addresses
Default: 0
These are equivalent to Turbo I4910 – I4925
MS{anynode}, M226 – MI249 (Reserved for Future Use)
Range: 0
Units: Modified 16-Axis MACRO Station Addresses
Default: 0
MS{anynode}, M250 – MI265 I/O Card Identification Variables
Range: 0
Units: Modified 16-Axis MACRO Station Addresses
Default: 0
These are equivalent to Turbo I4950 – I4965
MS{anynode},MI300 - MI899 (Reserved for future use)
MACRO/SERVO IC 4-Axis Servo IC MI-variables
Each MACRO IC has a set of these variables. Up to two Servo IC are attached to each MACRO IC. The
base addresses of the two Servo ICs are defined by MI179 and MI180. MI179 defines the base address of
the Servo IC that contains channels 1 – 4 and MI180 defines the base address of the Servo IC that
contains channels 5 – 8. MI-variables in the range MI900 to MI909 control multi-channel aspects of the
hardware setup for these two Servo ICs (ACC-24E2x’s).
MS{anynode},MI900 PWM 1-4 Frequency Control
Range: 0 - 32767
Units: PWM Frequency = 117,964.8 kHz / [4*MI900+6]
Default: 6527
PWM Frequency = 117,964.8 / 26114 = 4.5173 kHz
MI900 controls the PWM frequency for 16-Axis MACRO Station machine interface channels 1-4. It
does this by setting the limits of the PWM up-down counter, which increments and decrements at the
PWMCLK frequency of 117,964.8 kHz (117.9648 MHz).
The PWM frequency determines the actual switching frequency of amplifiers connected to any of the 16-
Axis MACRO Station’s first four machine interface channels with the direct PWM command. It is only
important if the direct PWM command signal format is used.
Generally, MI900 is set to the same value as MI992. If a different PWM frequency is desired for
channels 1 to 4, MI900 should be set so that it is an odd-integer multiple (e.g. 3x, 5x, 7x) of MI992, or
that MI992 is an odd-integer multiple of MI900. This will keep the PWM hardware on channels 1-4 in
synchronization with the software algorithms driven by the PHASE clock.
The maximum value that can be written into the PWM command register without full saturation is
MI900+1 on the positive end and -MI900-2 on the negative end. Generally, the "PWM scale factor" Ix66
for Motor x, which determines the maximum PWM command magnitude, is set to MI900 + 10%.
To set MI900 for a desired PWM frequency, the following formula can be used:
MI900 = (117,964.8 kHz / [4*PWM Freq (kHz)]) - 1 (rounded down)