mc1451a-e ETC-unknow, mc1451a-e Datasheet - Page 24

• Manufacturer Part Number: mc1451a-e
• Description: Advanced Brushless Motor Control Chipset
• Manufacturer: ETC-unknow

Register Name
destination position
maximum velocity
acceleration
maximum acceleration
jerk
ratio
Kp
Ki
Kd
Kvff
Integration limit
The double-buffered commands are: STOP, SMOOTH_STOP, and
SYNCH_PRFL.
Manual Update
There are two methods of manually updating the double-buffered
parameters, one for a single axis instantaneous update and one for a
multiple-axis update.
The single axis instantaneous update, which is specified using the
UPDATE command, forces the parameters for the current axis to be
updated at the next servo loop.
The multiple axis instantaneous update, which is specified using the
MULTI_UPDATE command, causes multiple axes to be updated
simultaneously. This can be useful when synchronized multi-axis
profiling is desired. This command takes a 1 word argument which
consists of a bit mask, with 1 bit assigned to each axis. Executing this
command has the same affect as instantaneously switching to each
desired axes, and executing an UPDATE command.
Breakpoints
A breakpoint is a convenient way of programming a profile or filter
change upon some specific condition. There are two types of
breakpoints, those that have a 32-bit comparitor value associated with
them and those that do not. For those that have the comparitor, a 32-bit
comparitor value is loaded into the breakpoint compare register first,
and then one of the breakpoint conditions is specified. For those
breakpoint modes without associated comparitor values only the
breakpoint condition needs to be specified.
The double-buffered registers and commands will be updated upon
satisfaction of the specified breakpoint condition.
Here is a list of all of the available breakpoint conditions.
Positive Target Position Breakpoint
A 32 bit position breakpoint can be specified which will result in
the parameters being updated when the current target position
(the instantaneous desired axis position output from the profile
Command to set
SET_POS
SET_VEL
SET_ACC
SET_MAX_ACC
SET_JERK
SET_RATIO
SET_KP
SET_KI
SET_KD
SET_KVFF
SET_I_LM
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Negative Target Position Breakpoint:.
Positive Actual Position Breakpoint
Negative Actual Position Breakpoint:.
Time Breakpoint
Motion Complete Breakpoint
External Breakpoint
Normally, whenever one of these conditions has been programmed and
the condition occurs, the double-buffered parameters will automatically
be shifted to the active registers. There is a mechanism to disable this
"automatic update upon breakpoint" however. This is discussed in the
next section.
The above breakpoint modes are particularly useful during multi-axis
motion. This is because the next profile commands (set of host-
specified trajectory commands) can be pre-loaded and activated at the
precise position or time required, with no delay incurred to send an
update or load parameters command.
generator) equals or exceeds the specified breakpoint value. This
breakpoint is set using the SET_POS_BRK command.
A 32 bit position breakpoint can be specified which will result in
the parameters being updated when the current target position
(the instantaneous desired axis position output from the profile
generator) equals or is less than the specified breakpoint
value.This breakpoint is set using the SET_NEG_BRK command.
A 32 bit position breakpoint can be specified which will result in
the parameters being updated when the current actual position
(the instantaneous position of the actual axis hardware) equals or
exceeds the specified breakpoint value.This breakpoint is set
using the SET_ACTL_POS_BRK command.
A 32 bit position breakpoint can be specified which will result in
the parameters being updated when the current actual position
(the instantaneous position of the actual axis hardware) equals or
is less than the specified breakpoint value.This breakpoint is set
using the SET_ACTL_NEG_BRK command.
A 32 bit time breakpoint can be specified which will result in the
parameters being updated when the # of servo loops executed
since chip set reset (the current chip set time) is equal to the time
breakpoint value.The # of servo loops continuously increases
until it rolls over from 2 32 - 1 back to 0.The time breakpoint is set
using the SET_TIME_BRK command.
A breakpoint can be specified which will result in the parameters
being updated when the previous motion has been completed
(motion complete bit is set). When using this breakpoint no 32 bit
compare value is required.
A breakpoint can be specified which will result in the parameters
being updated when the home signal of the corresponding axis
becomes active (low). When using this breakpoint no 32 bit
compare value is required. This breakpoint is useful whenever it is
desired that an external signal starts, stops, or otherwise modifies
the profile movement.