Delta Tau GEO BRICK LV User Manual
Turbo PMAC User Manual
Setting Up Turbo PMAC-Based Commutation and/or Current Loop
111
When used through a PMAC-style Servo IC, this requires the single DACs on two consecutive channels.
The higher (even) numbered DAC channel is the A DAC; the lower (odd) numbered DAC channel is the
B DAC.
The higher (even) numbered DAC channel is the A DAC; the lower (odd) numbered DAC channel is the
B DAC.
DAC Output Signals
The A and B DAC outputs should be connected to the phase command inputs on the sine-wave input
amplifier. If the inputs on the amplifier are single-ended, use the DAC+ output only, and leave the
complementary DAC- outputs floating; do not ground them. If the inputs on the amplifier are
complementary, use both the DAC+ and DAC- outputs. In either case, tie the AGND reference voltage
on the output connector to the reference voltage for the amplifier input.
amplifier. If the inputs on the amplifier are single-ended, use the DAC+ output only, and leave the
complementary DAC- outputs floating; do not ground them. If the inputs on the amplifier are
complementary, use both the DAC+ and DAC- outputs. In either case, tie the AGND reference voltage
on the output connector to the reference voltage for the amplifier input.
Amplifier-Enable and Fault Interface
On PMAC2-style interface and breakout boards, including the Acc-8A, 8E, and 24E2A, the amplifier-
enable outputs are dry-contact relays. Normally open, normally closed, sinking or sourcing
configurations from 12V to 24V can be chosen. Normally open contacts (closed when enabled) are
recommended for more fail-safe operation.
enable outputs are dry-contact relays. Normally open, normally closed, sinking or sourcing
configurations from 12V to 24V can be chosen. Normally open contacts (closed when enabled) are
recommended for more fail-safe operation.
On PMAC-style boards, the amplifier-enable outputs are optically isolated solid-state drivers with 24V,
100mA capability. On most boards, sinking or sourcing drivers can be chosen by the selection of
socketed driver IC. The factory default is sinking drivers.
100mA capability. On most boards, sinking or sourcing drivers can be chosen by the selection of
socketed driver IC. The factory default is sinking drivers.
The amplifier fault inputs are optically isolated 12V to 24V inputs. On newer designs with surface-mount
ICs, the isolators are AC Optos so sinking or sourcing drivers can be used. On older designs with
through-hole ICs, sinking drivers are required.
ICs, the isolators are AC Optos so sinking or sourcing drivers can be used. On older designs with
through-hole ICs, sinking drivers are required.
Encoder Feedback
Usually, sine-wave control is done with either digital quadrature encoders connected directly into the
controller (the breakout board is just a pass-through for these signals) or analog sine-cosine encoders
processed through an interpolator accessory. When using an interpolated analog encoder for servo
feedback, typically the uninterpolated digital encoder counter is used for the commutation feedback,
which does not require the high resolution of the servo.
controller (the breakout board is just a pass-through for these signals) or analog sine-cosine encoders
processed through an interpolator accessory. When using an interpolated analog encoder for servo
feedback, typically the uninterpolated digital encoder counter is used for the commutation feedback,
which does not require the high resolution of the servo.
Hall-Effect Commutation Flags
PMAC2-style Servo ICs have supplemental flags for each channel labeled T, U, V, and W. The U, V,
and W flags are commonly used for hall-effect commutation signals (or their optical equivalent) that
provide power-up phase position information.
and W flags are commonly used for hall-effect commutation signals (or their optical equivalent) that
provide power-up phase position information.
PMAC-style Servo ICs require the use of a second channel’s flags (usually the same channel as the
second DAC) as the supplemental flags for this purpose.
second DAC) as the supplemental flags for this purpose.
Turbo PMAC Parameter Setup
PMAC2-Style Servo IC Multi-Channel Setup
The PMAC2-style DSPGATE1 Servo ICs have a great deal of flexibility in supporting different hardware
interfaces. This means that there are certain registers that must be set up through I-variables to support
the desired mode of operation. This is not required if PMAC-style Servo ICs are used.
interfaces. This means that there are certain registers that must be set up through I-variables to support
the desired mode of operation. This is not required if PMAC-style Servo ICs are used.
Hardware Clock Frequency Control: I7m03, MI903, MI907
I7m03 (MS{anynode},MI903 or MS{anynode},MI907 on a MACRO Station) determines the
frequency of four hardware clock signals used for the machine interface channels on Servo IC m. These
can probably be left at the default values. The four hardware clock signals are SCLK (encoder sample
clock), PFM_CLK (pulse frequency modulator clock, DAC_CLK (digital-to-analog converter clock), and
ADC_CLK (analog-to-digital converter clock).
I7m03 (MS{anynode},MI903 or MS{anynode},MI907 on a MACRO Station) determines the
frequency of four hardware clock signals used for the machine interface channels on Servo IC m. These
can probably be left at the default values. The four hardware clock signals are SCLK (encoder sample
clock), PFM_CLK (pulse frequency modulator clock, DAC_CLK (digital-to-analog converter clock), and
ADC_CLK (analog-to-digital converter clock).