Delta Tau GEO BRICK LV User Manual
Turbo PMAC User Manual
Turbo PMAC System Configuration and Auto Configuration
29
MACRO Ring Frequency Control Variables
The MACRO ring update frequency is the phase clock frequency of the ring master controller. If there is
more than one Turbo PMAC2 controller on the ring, only one of them can be the ring master controller
(others are masters, but not ring masters). Of course, if there is only one Turbo PMAC2 controller on the
ring, it will be the ring master controller. Determining which Turbo PMAC2 (technically, which
MACRO IC on a Turbo PMAC2) is ring master is explained below.
more than one Turbo PMAC2 controller on the ring, only one of them can be the ring master controller
(others are masters, but not ring masters). Of course, if there is only one Turbo PMAC2 controller on the
ring, it will be the ring master controller. Determining which Turbo PMAC2 (technically, which
MACRO IC on a Turbo PMAC2) is ring master is explained below.
While the ring master has the capability to force the clock generation of other devices on the ring into
synchronization, it is strongly recommended that all devices on the ring, both other Turbo PMAC2
controllers, and any slave devices, be set up for the same phase clock frequency. Determining which IC
sets the phase clock frequency and the actual setting the phase clock frequency for a Turbo PMAC2
controller is explained above.
synchronization, it is strongly recommended that all devices on the ring, both other Turbo PMAC2
controllers, and any slave devices, be set up for the same phase clock frequency. Determining which IC
sets the phase clock frequency and the actual setting the phase clock frequency for a Turbo PMAC2
controller is explained above.
For a Turbo PMAC2 driving a MACRO ring, MACRO IC 0 should generate the phase clock signal. This
means that I19 should be set to 6807 (which it will be by default on virtually any Turbo PMAC2 capable
of driving a MACRO ring), and that I6800 and I6801 set the phase clock frequency.
means that I19 should be set to 6807 (which it will be by default on virtually any Turbo PMAC2 capable
of driving a MACRO ring), and that I6800 and I6801 set the phase clock frequency.
I7: Phase Cycle Extension
On the Turbo PMAC2 board, it is possible to skip hardware phase clock cycles between executions of the
phase update software. A Turbo PMAC2 board will execute the phase update software – commutation
and/or current-loop closure – every (I7+1) hardware phase clock cycles. The default value for I7 is 0, so
normally Turbo PMAC2 executes the phase update software every hardware phase clock cycle.
phase update software. A Turbo PMAC2 board will execute the phase update software – commutation
and/or current-loop closure – every (I7+1) hardware phase clock cycles. The default value for I7 is 0, so
normally Turbo PMAC2 executes the phase update software every hardware phase clock cycle.
If the Turbo PMAC2 board is closing the current loop for direct PWM control over the MACRO ring, it is
desirable to have two hardware ring update cycles (which occur at the hardware phase clock frequency)
per software phase update. This eliminates one ring cycle of delay in the current loop, which permits
slightly higher gains and performance. To do this, I7 would be set to 1, so the phase update software
would execute every second hardware phase clock cycle, and ring update cycle.
desirable to have two hardware ring update cycles (which occur at the hardware phase clock frequency)
per software phase update. This eliminates one ring cycle of delay in the current loop, which permits
slightly higher gains and performance. To do this, I7 would be set to 1, so the phase update software
would execute every second hardware phase clock cycle, and ring update cycle.
Normally it is desirable to close the current loop at an update rate of about 9 kHz (the default rate). If two
ring updates were desired per current loop update, the ring update frequency would need to be set to 18
kHz. This is possible if there are no more than 40 total active nodes on the ring. To implement this,
I6800 would be set to one-half of the default value, and I6801 to the default value of 0.
ring updates were desired per current loop update, the ring update frequency would need to be set to 18
kHz. This is possible if there are no more than 40 total active nodes on the ring. To implement this,
I6800 would be set to one-half of the default value, and I6801 to the default value of 0.
Note:
When making this change, change the Turbo PMAC2’s I6800 variable first, then
the MACRO Station’s MI992. Changing the MACRO Station’s MI992 alone,
followed by an MSSAVE command and an MS$$$, could cause the Station’s
watchdog timer to trip.
the MACRO Station’s MI992. Changing the MACRO Station’s MI992 alone,
followed by an MSSAVE command and an MS$$$, could cause the Station’s
watchdog timer to trip.
I6840: MACRO IC 0 Master Configuration
Any MACRO IC on a Turbo PMAC2 talking to a MACRO Station must be configured as a master on the
ring. For purposes of the MACRO protocol, each MACRO IC is a separate logical master with its own
master number, even though there may be multiple MACRO ICs on a single physical Turbo PMAC2.
ring. For purposes of the MACRO protocol, each MACRO IC is a separate logical master with its own
master number, even though there may be multiple MACRO ICs on a single physical Turbo PMAC2.
Each ring must have one and only one ring controller (synchronizing master). This should be the
MACRO IC 0 one and only one of the Turbo PMAC2 boards on the ring.
MACRO IC 0 one and only one of the Turbo PMAC2 boards on the ring.
On a Turbo PMAC2, set I6840 to $30 to make the card’s MACRO IC 0 the ring controller. This sets bits
4 and 5 of the variable to 1. Setting bit 4 to 1 makes the IC a master on the ring; setting bit 5 to 1 makes
the IC the ring controller” starting each ring cycle by itself.
4 and 5 of the variable to 1. Setting bit 4 to 1 makes the IC a master on the ring; setting bit 5 to 1 makes
the IC the ring controller” starting each ring cycle by itself.
On a Turbo PMAC2 whose MACRO IC 0 will be a master but not ring controller, I6840 should be set to
$90. This sets bits 4 and 7 of the variable to 1. Setting bit 4 to 1 makes the IC a master on the ring;
setting bit 7 to 1 will cause this IC to be synchronized to the ring controller IC every time it receives a
ring packet specified by I6841.
$90. This sets bits 4 and 7 of the variable to 1. Setting bit 4 to 1 makes the IC a master on the ring;
setting bit 7 to 1 will cause this IC to be synchronized to the ring controller IC every time it receives a
ring packet specified by I6841.