code_notes.lyx

CNC 的开放码,EMC2 V2.2.8版

 Otherwise the machine is placed in teleop mode.
 The kinematics code is activated, interpolators are drained and flushed,
 and the Cartesian velocity commands are set to zero.
\layout Subsection

COORD
\layout Standard

The COORD command places the machine in coordinated mode.
 In coord mode, movement of the machine is based on Cartesian coordinates
 using kinematics, rather than on individual joints as in free mode.
 In addition, the main trajectory planner is used to generate motion, based
 on queued LINE, CIRCLE, and/or PROBE commands.
 Coord mode is the mode that is used when executing a G-code program.
 
\layout Subsubsection

Requirements
\layout Standard

The command handler will reject the COORD command with an error message
 if the kinematics cannot be activated because the one or more axes have
 not been homed.
 In addition, if any joint is in motion (GET_MOTION_INPOS_FLAG() == FALSE),
 then the command will be ignored (with no error message).
 This behaviour is controlled by code that is now located in the function
 
\begin_inset Quotes eld
\end_inset 

set_operating_mode()
\begin_inset Quotes erd
\end_inset 

 in control.c.
 I believe the command should not be silently ignored, instead the command
 handler should determine whether it can be executed and return an error
 if it cannot.
\layout Subsubsection

Results
\layout Standard

If the machine is already in coord mode, nothing.
 Otherwise, the machine is placed in coord mode.
 The kinematics code is activated, interpolators are drained and flushed,
 and the trajectory planner queues are empty.
 The trajectory planner is active and awaiting a LINE, CIRCLE, or PROBE
 command.
\layout Subsection

ENABLE
\layout Standard

The ENABLE command enables the motion controller.
\layout Subsubsection

Requirements
\layout Standard

None.
 The command can be issued at any time, and will always be accepted.
\layout Subsubsection

Results
\layout Standard

If the controller is already enabled, nothing.
 If not, the controller is enabled.
 Queues and interpolators are flushed.
 Any movement or homing operations are terminated.
 The amp-enable outputs associated with active joints are turned on.
 If forward kinematics are not available, the machine is switched to free
 mode.
\layout Subsection

DISABLE
\layout Standard

The DISABLE command disables the motion controller.
\layout Subsubsection

Requirements
\layout Standard

None.
 The command can be issued at any time, and will always be accepted.
\layout Subsubsection

Results
\layout Standard

If the controller is already disabled, nothing.
 If not, the controller is disabled.
 Queues and interpolators are flushed.
 Any movement or homing operations are terminated.
 The amp-enable outputs associated with active joints are turned off.
 If forward kinematics are not available, the machine is switched to free
 mode.
\layout Subsection

ENABLE_AMPLIFIER
\layout Standard

The ENABLE_AMPLIFIER command turns on the amp enable output for a single
 output amplifier, without changing anything else.
 Can be used to enable a spindle speed controller.
\layout Subsubsection

Requirements
\layout Standard

None.
 The command can be issued at any time, and will always be accepted.
\layout Subsubsection

Results
\layout Standard

Currently, nothing.
 (A call to the old extAmpEnable function is currently commented out.) Eventually
 it will set the amp enable HAL pin true.
\layout Subsection

DISABLE_AMPLIFIER
\layout Standard

The DISABLE_AMPLIFIER command turns off the amp enable output for a single
 amplifier, without changing anything else.
 Again, useful for spindle speed controllers.
\layout Subsubsection

Requirements
\layout Standard

None.
 The command can be issued at any time, and will always be accepted.
\layout Subsubsection

Results
\layout Standard

Currently, nothing.
 (A call to the old extAmpEnable function is currently commented out.) Eventually
 it will set the amp enable HAL pin false.
\layout Subsection

ACTIVATE_JOINT
\layout Standard

The ACTIVATE_JOINT command turns on all the calculations associated with
 a single joint, but does not change the joint's amp enable output pin.
\layout Subsubsection

Requirements
\layout Standard

None.
 The command can be issued at any time, and will always be accepted.
\layout Subsubsection

Results
\layout Standard

Calculations for the specified joint are enabled.
 The amp enable pin is not changed, however, any subsequent ENABLE or DISABLE
 commands will modify the joint's amp enable pin.
\layout Subsection

DEACTIVATE_JOINT
\layout Standard

The DEACTIVATE_JOINT command turns off all the calculations associated with
 a single joint, but does not change the joint's amp enable output pin.
\layout Subsubsection

Requirements
\layout Standard

None.
 The command can be issued at any time, and will always be accepted.
\layout Subsubsection

Results
\layout Standard

Calculations for the specified joint are enabled.
 The amp enable pin is not changed, and subsequent ENABLE or DISABLE commands
 will not modify the joint's amp enable pin.
\layout Subsection

ENABLE_WATCHDOG
\layout Standard

The ENABLE_WATCHDOG command enables a hardware based watchdog (if present).
\layout Subsubsection

Requirements
\layout Standard

None.
 The command can be issued at any time, and will always be accepted.
\layout Subsubsection

Results
\layout Standard

Currently nothing.
 The old watchdog was a strange thing that used a specific sound card.
 A new watchdog interface may be designed in the future.
\layout Subsection

DISABLE_WATCHDOG
\layout Standard

The DISABLE_WATCHDOG command disables a hardware based watchdog (if present).
\layout Subsubsection

Requirements
\layout Standard

None.
 The command can be issued at any time, and will always be accepted.
\layout Subsubsection

Results
\layout Standard

Currently nothing.
 The old watchdog was a strange thing that used a specific sound card.
 A new watchdog interface may be designed in the future.
\layout Subsection

PAUSE
\layout Standard

The PAUSE command stops the trajectory planner.
 It has no effect in free or teleop mode.
 At this point I don't know if it pauses all motion immediately, or if it
 completes the current move and then pauses before pulling another move
 from the queue.
\layout Subsubsection

Requirements
\layout Standard

None.
 The command can be issued at any time, and will always be accepted.
\layout Subsubsection

Results
\layout Standard

The trajectory planner pauses.
\layout Subsection

RESUME
\layout Standard

The RESUME command restarts the trajectory planner if it is paused.
 It has no effect in free or teleop mode, or if the planner is not paused.
 
\layout Subsubsection

Requirements
\layout Standard

None.
 The command can be issued at any time, and will always be accepted.
\layout Subsubsection

Results
\layout Standard

The trajectory planner resumes.
\layout Subsection

STEP
\layout Standard

The STEP command restarts the trajectory planner if it is paused, and tells
 the planner to stop again when it reaches a specific point.
 It has no effect in free or teleop mode.
 At this point I don't know exactly how this works.
 I'll add more documentation here when I dig deeper into the trajectory
 planner.
\layout Subsubsection

Requirements
\layout Standard

None.
 The command can be issued at any time, and will always be accepted.
\layout Subsubsection

Results
\layout Standard

The trajectory planner resumes, and later pauses when it reaches a specific
 point.
\layout Subsection

OPEN_LOG, START_LOG, STOP_LOG, CLOSE_LOG
\layout Standard

These commands are used to control the logging feature of the motion controller.
 Logging will probably be changed in the near future, so I'm not attempting
 to document these commands in detail right now.
 Parts of the logging feature may be replaced by halscope and other tools,
 other parts will be retained.
 
\layout Subsubsection

Requirements
\layout Standard

To be documented later.
\layout Subsubsection

Results
\layout Standard

To be documented later.
\layout Subsection

SCALE
\layout Standard

The SCALE command scales all velocity limits and commands by a specified
 amount.
 It is used to implement feed rate override and other similar functions.
 The scaling works in free, teleop, and coord modes, and affects everything,
 including homing velocities, etc.
 However, individual joint velocity limits are unaffected.
\layout Subsubsection

Requirements
\layout Standard

None.
 The command can be issued at any time, and will always be accepted.
\layout Subsubsection

Results
\layout Standard

All velocity commands are scaled by the specified constant.
\layout Subsection

OVERRIDE_LIMITS
\layout Standard

The OVERRIDE_LIMITS command prevents limits from tripping until the end
 of the next JOG command.
 It is normally used to allow a machine to be jogged off of a limit switch
 after tripping.
 (The command can actually be used to override limits, or to cancel a previous
 override.)
\layout Subsubsection

Requirements
\layout Standard

None.
 The command can be issued at any time, and will always be accepted.
 (I think it should only work in free mode.)
\layout Subsubsection

Results
\layout Standard

Limits on all joints are over-ridden until the end of the next JOG command.
 (This is currently broken...
 once an OVERRIDE_LIMITS command is received, limits are ignored until another
 OVERRIDE_LIMITS command re-enables them.)
\layout Subsection

HOME
\layout Standard

The HOME command initiates a homing sequence on a specified joint.
 The actual homing sequence is determined by a number of configuration parameter
s, and can range from simply setting the current position to zero, to a
 multi-stage search for a home switch and index pulse, followed by a move
 to an arbitrary home location.
 For more information about the homing sequence, see section 
\begin_inset LatexCommand \ref{sec:Homing}

\end_inset 

 of this document.
\layout Subsubsection

Requirements
\layout Standard

The command will be ignored silently unless the machine is in free mode.
\layout Subsubsection

Results
\layout Standard

Any jog or other joint motion is aborted, and the homing sequence starts.
\layout Subsection

JOG_CONT
\layout Standard

The JOG_CONT command initiates a continuous jog on a single joint.
 A continuous jog is generated by setting the free mode trajectory planner's
 target position to a point beyond the end of the joint's range of travel.
 This ensures that the planner will move constantly until it is stopped
 by either the joint limits or an ABORT command.
 Normally, a GUI sends a JOG_CONT command when the user presses a jog button,
 and ABORT when the button is released.
\layout Subsubsection

Requirements
\layout Standard

The command handler will reject the JOG_CONT command with an error message
 if machine is not in free mode, or if any joint is in motion (GET_MOTION_INPOS_
FLAG() == FALSE), or if motion is not enabled.
 It will also silently ignore the command if the joint is already at or
 beyond it's limit and the commanded jog would make it worse.
 
\layout Subsubsection

Results
\layout Standard

The free mode trajectory planner for the joint identified by emcmotCommand->axis
 is activated, with a target position beyond the end of joint travel, and
 a velocity limit of emcmotCommand->vel.
 This starts the joint moving, and the move will continue until stopped
 by an ABORT command or by hitting a limit.
 The free mode planner accelerates at the joint accel limit at the beginning
 of the move, and will decelerate at the joint accel limit when it stops.
\layout Subsection

JOG_INCR
\layout Standard

The JOG_INCR command initiates an incremental jog on a single joint.
 Incremental jogs are cumulative, in other words, issuing two JOG_INCR commands
 that each ask for 0.100 inches of movement will result in 0.200 inches of
 travel, even if the second command is issued before the first one finishes.
 Normally incremental jogs stop when they have travelled the desired distance,
 however they also stop when they hit a limit, or on an ABORT command.
\layout Subsubsection

Requirements
\layout Standard

The command handler will silently reject the JOG_INCR command if machine
 is not in free mode, or if any joint is in motion (GET_MOTION_INPOS_FLAG()
 == FALSE), or if motion is not enabled.
 It will also silently ignore the command if the joint is already at or
 beyond it's limit and the commanded jog would make it worse.
 
\layout Subsubsection

Results
\layout Standard