MC1151A PMD, MC1151A Datasheet - Page 37

• Manufacturer Part Number: MC1151A
• Description: (MC1x51A) Advanced Step Motor Control Chipset
• Manufacturer: PMD

This command is available on the MC1451A-E, MC1251A-E, and
MC1151A-E parts only.
SET_START_VEL
Data/direction:
Encoding:
Axis acted on:
Available on:
Double buffered:
SET_START_VEL sets the minimum allowed velocity. This command
is used during the trapezoidal and velocity contouring profile modes,
and is useful in conjunction with systems that may be induced to
oscillate if operated at too low a speed. The starting velocity is specified
as an unsigned 32-bit number with units of steps/cycle. The data word
scaling is 1/2 16. The range is 0 to +1,073,741,823.
The starting velocity must always be smaller than the maximum
velocity set using the SET_VEL command.
This command is not used with the S-curve and electronic gear
profile modes.
The starting velocity parameter is not double buffered. It takes
affect immediately, not after an UPDATE command.
STOP
Data/direction:
Encoding:
Axis acted on:
Available on:
Double buffered:
STOP, also known as CLR_PRFL in earlier chipset versions, stops the
current axis by setting the target velocity to zero. This function will not
be performed until a parameter update occurs. After the update occurs
the axis trajectory generator will stop and the motion complete bit will
be set. This command is useful for stopping the axis abruptly.
SMOOTH_STOP
Data/direction:
Encoding:
Axis acted on:
Available on:
Double buffered:
SMOOTH_STOP stops the current axis by setting the desired velocity
to zero, resulting in a controlled deceleration of the axis eventually to a
velocity of 0. The deceleration profile will mirror the acceleration profile
for the current profile mode. For example if the SMOOTH_STOP
command is given during an s-curve profile the deceleration profile may
have up to three phases, depending on the # of phases during the
acceleration profile, and if the SMOOTH_STOP command is given
Set starting velocity
2/write
6a (hex)
current axis
all axes
no
Abruptly stop current axis motion
none
46 (hex)
current axis
all axes
yes
Smoothly stop current axis motion
none
4e (hex)
current axis
all axes
yes
37
during a trapezoidal profile or a velocity mode profile the deceleration
will be linear, with a value equal to the acceleration parameter.
This command does not function when the profile mode is set to
Electronic Gear.
SYNCH_PRFL
Data/direction:
Encoding:
Axis acted on:
Available on:
Double buffered:
SYNCH_PRFL sets the trajectory profile generator target position (in
steps) equal to the actual axis position (in encoder counts), clearing the
following error. This command is available for all profile types. This
function will not be performed until a parameter update occurs.
The SYNCH_PRFL command does not set the target velocity to
zero. If it is desired that the axis not move after a SYNCH_PRFL
command then a STOP command, in addition to the SYNCH_PRFL
command should be used.
This command is available on the MC1451A-E, MC1251A-E, and
MC1151A-E parts only.
GET_POS
Data/direction:
Encoding:
Axis acted on:
Available on:
Double buffered:
GET_POS returns the destination position set using the SET_POS
command. It returns the double-buffered value (set directly by the host),
which may or may not correspond to the active value, depending on
whether the profile parameters have been updated. The returned
position is a signed 32-bit number with units of steps.
GET_VEL
Data/direction:
Encoding:
Axis acted on:
Available on:
Double buffered:
GET_VEL returns the maximum velocity set using the SET_VEL
command. It returns the double-buffered value (set directly by the host),
which may or may not correspond to the active value, depending on
whether the profile parameters have been updated. The returned
Set target position equal to the actual
position
none
47 (hex)
current axis
all axes
yes
Get command position
2/read
4a (hex)
current axis
all axes
-
Get command velocity
2/read
4b (hex)
current axis
all axes
-