In MOVJ or JUMP mode, if the two points are the same, only different in arm orientations, J1 or J4 may be limited when Dobot M1 is moving, resulting in an alarm generated. You need to modify and resave the point for which the alarm is generated, and then clear the alarm manually.

The R-coordinate is the sum of the coordinates of J1, J2 and J4. The terminal posture relative to the origin stays constant when moving Dobot M1. Table 6.12 lists how to calculate each Joint coordinate after switching the arm orientation at the same point.

Table 6.12 Joint coordinate calculation

Before |
After |

R=J1+J2+J4 |
R’=R=J1’+J2’+J4’ |

J1 |
J1’=J1+J2 |

J2 |
J2’=-J2 |

J3 |
J3’=J3 |

J4 |
J4’=R-J1’-J2’ |

As shown in Table 6.12, If the J1-coordinate is 10° and the J2-coordinate is 90° before switching the arm orientation, the J1-coordinate will change to 100° after switching, resulting in an alarm about limit generated. In real application scenario, if the two successive saved points are the same, only different in arm orientations, please notice the coordinates of J1 and J4. You can calculate J1-coordinate and J4-coordinate according to Table 6.12, in order to avoid generating an alarm about limitation.