Change work offset values in a Pure Python remap w/o self.execute()

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Aciera
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09 Feb 2023 16:52 #264150 by Aciera

Change work offset values in a Pure Python remap w/o self.execute() was created by Aciera

I'm working on a pure python remap for G68.2 and affiliated Gcodes and I have fallen down the 'yield INTERP_EXECUTE_FINISH' hole.
I needed 'yield INTERP_EXECUTE_FINISH' because I have to wait for a joint move to finish before I can continue with replacing the active work offset values (ie G54 or whatever is active). The line I used for this was
'self.execute("G10 L2 P0 X%f Y%f Z%f " % (P[0],P[1],P[2]) ,lineno())'
with P holding the new offset values.
Now however I cannot use any 'self.execute(...)' because of the preceeding 'yield INTERP_EXECUTE_FINISH'. So I came up with this to write the new offset values directly into the numbered parameters:

    # get which offset is active (g54=1 .. g59.3=9)
    active_offset = int(self.params[5220])
    # set the relevant parameter numbers that hold the active offset values
    # (G54_x: #5221, G55_x:#[5221+20], G56_x:#[5221+40] ....)
    work_offset_x = (active_offset-1)*20 + 5221
    work_offset_y = work_offset_x + 1
    work_offset_z = work_offset_x + 2

    self.params[work_offset_x] = P[0]
    self.params[work_offset_y] = P[1]
    self.params[work_offset_z] = P[2]

This works and it writes the values into the parameters but they aren't actually read and used unless I reload them with an mdi command like 'G54' which I can't do from the remap because I can't use 'self.execute(..)'.
So if anybody knows of a way to do this from a remap without using 'self.execute(..)' let me know please.

Warning: Spoiler!

# orient the tool to the current twp (with TCP)
# some mfgs offer an optional P-word to give preferred rotation directions
def g536(self):
    global saved_work_offset
    global twp_flag
    # reset the twp build
    twp_flag = [0, 'empty']

    # switch to identity kins
    hal.set_p("motion.switchkins-type",str(0))

    # calculate the required rotary joint positions and
    # pre_rotation for the requested tool-orientation
    a_j, b_j, pre_rot = twp_calc_jnts_pos_and_pre_rot(self)
    gui_update_twp(self)

    # switch to tcp kins
    print("G53.6: Activating TCP kins")
    hal.set_p("motion.switchkins-type",str(1))
    kins_comp_set_pre_rot(self, pre_rot)

    print(" mdi moving joints A, B: ", a_j, b_j)
    # build and send the gcode command to move to the new joint positions
    #self.execute("G0 A%f B%f " % (a, b), lineno())

    # read and remember coordiantes in the begining of the operation
    # you may have more or less coords - syntax and logic are the same
    x_pos = round(emccanon.GET_EXTERNAL_POSITION_X(), 3)
    y_pos = round(emccanon.GET_EXTERNAL_POSITION_Y(), 3)
    z_pos = round(emccanon.GET_EXTERNAL_POSITION_Z(), 3)
    c_pos = round(emccanon.GET_EXTERNAL_POSITION_C(), 3)
    emccanon.STRAIGHT_TRAVERSE(2, x_pos, y_pos, z_pos, a_j*(180/pi), b_j*(180/pi), c_pos, 0,0,0)

    yield INTERP_EXECUTE_FINISH

    # calculate the offsets in tool-coords
    P = matrix_to_point(kins_calc_tool_transformation(self, point_to_matrix(saved_work_offset)))
    print("Setting transformed work-offsets in tool-kins: ", P)
    # put the calcualted offset values into the relevant parameters
    #self.execute("G10 L2 P0 X%f Y%f Z%f " % (P[0],P[1],P[2]) ,lineno())

    # get which offset is active (g54=1 .. g59.3=9)
    active_offset = int(self.params[5220])
    # set the relevant parameter numbers that hold the active offset values
    # (G54_x: #5221, G55_x:#[5221+20], G56_x:#[5221+40] ....)
    work_offset_x = (active_offset-1)*20 + 5221
    work_offset_y = work_offset_x + 1
    work_offset_z = work_offset_x + 2

    self.params[work_offset_x] = P[0]
    self.params[work_offset_y] = P[1]
    self.params[work_offset_z] = P[2]

    # same as above but for twp-offsets used for twp origin as set by g68.2 (x,y,z)-words
    # g69 will set the twp-offsets to zero.
    current_twp_offset = params_get_current_twp_offset(self)
    P = matrix_to_point(kins_calc_tool_transformation(self, point_to_matrix(current_twp_offset)))
    print("Setting transformed twp-offset in tool-kins: ", P)
    hal.set_p("gen_xyzabc_trsrn_kins.twp-x",str(P[0]))
    hal.set_p("gen_xyzabc_trsrn_kins.twp-y",str(P[1]))
    hal.set_p("gen_xyzabc_trsrn_kins.twp-z",str(P[2]))

    # switch to tool kins
    hal.set_p("motion.switchkins-type",str(3))

    # we only want to update the offsets as those get rotated by rotary-joint positions
    # while the twp is rotated using the method chosen by the g68.2 p-word
    gui_update_offsets(self)

    return INTERP_OK

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Aciera
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09 Feb 2023 17:09 #264154 by Aciera

Replied by Aciera on topic Change work offset values in a Pure Python remap w/o self.execute()

Ok, never mind I just found it:

emccanon.SET_G5X_OFFSET(0, P[0], P[1], P[2], 0,0,0,0,0,0)

The following user(s) said Thank You: tommylight

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Aciera
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10 Feb 2023 15:25 #264227 by Aciera

Replied by Aciera on topic Change work offset values in a Pure Python remap w/o self.execute()

Just an update in case somebody comes across this in the future as there are some odd thing with this:
1.
emccanon.SET_G5X_OFFSET(0, P[0], P[1], P[2], 0,0,0,0,0,0)
With index '0' seems to write to G53 and the axis DRO is then stuck at G53
A 'G53 X0Y0Z0' ignores the new values and uses the old offset (x100y0z0 in my case)

2.
emccanon.SET_G5X_OFFSET(1, P[0], P[1], P[2], 0,0,0,0,0,0)
With index '1' seems to write to G54 just fine but also doesn't seem to update G53 properly.
So a 'G53 G0 X0 Y0 Z0' will ignore the offset-change with the above emccanon.SET_G5X_OFFSET(...)

If anybody has an idea I could get this to work please let me know.

This is the code I'm using:

Warning: Spoiler!

# orient the tool to the current twp (with TCP)
# some mfgs offer an optional P-word to give preferred rotation directions
def g536(self):
    global saved_work_offset
    global twp_flag
    # reset the twp build
    twp_flag = [0, 'empty']
    # switch to identity kins
    hal.set_p("motion.switchkins-type",str(0))
    yield INTERP_EXECUTE_FINISH

    # calculate the required rotary joint positions and
    # pre_rotation for the requested tool-orientation
    a_j, b_j, pre_rot = twp_calc_jnts_pos_and_pre_rot(self)
    gui_update_twp(self)
    # switch to tcp kins
    print("G53.6: Activating TCP kins")
    hal.set_p("motion.switchkins-type",str(1))
    kins_comp_set_pre_rot(self, pre_rot)
    yield INTERP_EXECUTE_FINISH

    print(" mdi moving joints A, B: ", a_j, b_j)
    # store current coordiantes because emccanon wants values for all nine axes
    x_pos = emccanon.GET_EXTERNAL_POSITION_X()
    y_pos = emccanon.GET_EXTERNAL_POSITION_Y()
    z_pos = emccanon.GET_EXTERNAL_POSITION_Z()
    c_pos = emccanon.GET_EXTERNAL_POSITION_C()
    emccanon.STRAIGHT_TRAVERSE(2, x_pos, y_pos, z_pos, a_j*(180/pi), b_j*(180/pi), c_pos, 0,0,0)
    yield INTERP_EXECUTE_FINISH

    # calculate the work offset in tool-coords
    P = matrix_to_point(kins_calc_tool_transformation(self, point_to_matrix(saved_work_offset)))
    print("Setting transformed work-offsets in tool-kins: ", P)
    # note: index 0=g53, 1=g54 etc
    emccanon.SET_G5X_OFFSET(0, P[0], P[1], P[2], 0,0,0,0,0,0)
    emccanon.SET_G5X_OFFSET(1, P[0], P[1], P[2], 0,0,0,0,0,0)
    # same as above but for twp-offsets used for twp origin as set by g68.2 (x,y,z)-words
    # g69 will set the twp-offsets to zero.
    current_twp_offset = params_get_current_twp_offset(self)
    P = matrix_to_point(kins_calc_tool_transformation(self, point_to_matrix(current_twp_offset)))
    print("Setting transformed twp-offset in tool-kins: ", P)
    hal.set_p("gen_xyzabc_trsrn_kins.twp-x",str(P[0]))
    hal.set_p("gen_xyzabc_trsrn_kins.twp-y",str(P[1]))
    hal.set_p("gen_xyzabc_trsrn_kins.twp-z",str(P[2]))
    yield INTERP_EXECUTE_FINISH

    # switch to tool kins
    hal.set_p("motion.switchkins-type",str(3))
    yield INTERP_EXECUTE_FINISH

    # we only want to update the offsets as those get rotated by rotary-joint positions
    # while the twp is rotated using the method chosen by the g68.2 p-word
    gui_update_offsets(self)

    yield INTERP_OK

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cmorley
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11 Feb 2023 08:14 #264276 by cmorley

Replied by cmorley on topic Change work offset values in a Pure Python remap w/o self.execute()

AFAIU G53 should be set by homing and never be changed - that is the machines base offsets.

emccanon.SET_G5X_OFFSET(0, P[0], P[1], P[2], 0,0,0,0,0,0) index '0' could very well be 'set the current user system' - that is what it does in the higher gcode level. But that is not reliable in gcode programs as read-ahead can mess it up.

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Aciera
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11 Feb 2023 10:31 - 11 Feb 2023 10:35 #264284 by Aciera

Replied by Aciera on topic Change work offset values in a Pure Python remap w/o self.execute()

AFAIU G53 should be set by homing and never be changed - that is the machines base offsets.

For some reason I used to think that 'G93 x0y0z0' would take the machine to the position where all joint positions are zero.

emccanon.SET_G5X_OFFSET(0, P[0], P[1], P[2], 0,0,0,0,0,0) index '0' could very well be 'set the current user system' - that is what it does in the higher gcode level.

It seems a bit odd, neither here nor there:

Last edit: 11 Feb 2023 10:35 by Aciera.

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Aciera
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11 Feb 2023 10:39 #264285 by Aciera

Replied by Aciera on topic Change work offset values in a Pure Python remap w/o self.execute()

I start the config, home the machine and in MDI I set G54 and command to go to machine home:
g10 l2 p0 x100 y100 z100 a0 b0
g53 g0 x0 y0 z0
Nothing moves since we are already in home position and the DRO (as expected) reads:

Now I call a G69.9 remap that looks like this:

Warning: Spoiler!

and the DRO changes to this:

then do an MDI call to go to machine home position: g53 g0 x0 y0 z0
and I get this:

and a follow MDI command: g54 g0 x0 y0 z0
gives me this:

l don't get it.

Anyway I decided to leave that alone and I manged to do the offset transformation before calling 'yield INTERP_EXECUTE_FINISH' so I could use 'self.execute(..)'

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andypugh
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20 Feb 2023 22:50 #264913 by andypugh

Replied by andypugh on topic Change work offset values in a Pure Python remap w/o self.execute()

I think that it is probably better to use emccanon commands in general.

Rather than self.execute("G53 G0...") try using emccanon.STRAIGHT_TRAVERSE()
github.com/LinuxCNC/linuxcnc/blob/master...l_intf/canon.hh#L245

Reading through the code in interp_convert.cc it seems like G53 is achieved by subtracting all the offsets from the commanded position and making the move in program coordinates, but I am not entirely clear about that.

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