Reference Manual

Turbo PMAC/PMAC2 Software Reference
Change Summary: PMAC to Turbo PMAC 745
Commutation Changes
PMAC/PMAC2
Turbo PMAC/PMAC2
Commutation lookup table has 256 entries; direct
microstepping yields 64 microsteps per step
Commutation lookup table has 2048 entries; direct
microstepping yields 512 microsteps per step
Phase reference error bit only set on unsuccessful
phasing search or read. Loop is not closed then, but
may be subsequently closed.
For any synchronous motor commutated by Turbo
PMAC, phase reference error bit set automatically
on power-up/reset. Cleared only on successful
phasing search or read. Loop cannot be closed if bit
is set.
Phasing search move on $ command is exclusive
background task. No other background task can
execute until phasing search move is complete.
Command acknowledgment to host is not given
until move is complete.
Phasing search move on $ command is non-
exclusive background task. Other background tasks
can execute while phasing search move is in
progress. Command acknowledgment to host is
given when move starts.
Overtravel Limit Changes
PMAC/PMAC2
Turbo PMAC/PMAC2
If hardware or software overtravel limit is hit while
in open-loop mode, motor loop is closed (zero-
velocity)
If hardware or software overtravel limit is hit while
in open-loop mode, motor is killed (amp disabled,
zero command).
Cutter Radius Compensation Changes
PMAC/PMAC2
Turbo PMAC/PMAC2
Two-dimensional compensation only
Two-dimensional or three-dimensional
compensation
2D compensation cannot “see through” out-of-plane
move to maintain compensation properly in all
cases.
Special CCBUF can be defined to store out-of-plane
moves in 2D compensation to maintain proper
compensation through these moves.
Communications Changes
PMAC/PMAC2
Turbo PMAC/PMAC2
Characters received on any communications port are
loaded into a common command queue, so
simultaneous commands from multiple ports are
intermixed and garbled.
Characters received on each communications port
are loaded into a separate command queue for that
port, so that simultaneous commands from multiple
ports can be accepted properly.
When a program buffer is open, it can accept
commands from any port into the buffer, so another
port cannot give on-line commands (in general).
A program buffer is opened for a particular port
only; only commands from that port can be entered
into the buffer; other ports can only give on-line
commands.