
B–62073E–1/042. INTERFACE BETWEEN CNC AND PMC–NA OR NB
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6 Alarm issue in torque control mode
In torque control mode, if a servo alarm is issued for any axis, or if an OT alarm is issued for a torque–
controlled axis, torque control mode is canceled. Other alarms or resets do not cancel torque control
mode.
7 Outputting the torque control mode signal
The torque control mode signal (TRQMx) goes high once torque control mode has been established.
Signal address
M and T: F66.1, F70.1, F74.1, ...
TT: F130.1, F134.1, F138.1, ...
(2) Switching from torque control to position control (canceling torque control mode)
Torque control is canceled in the following cases:
1) The feedrate command skip signal (VCSKPx) is set to high when the execution wait buffer is
empty or contains a command block other than the torque control command.
2) The PMC axis control signal (PCAXx) is set to low to switch from PMC axis control to CNC axis
control.
3) A servo alarm is issued.
4) An OT alarm is issued for a torque–controlled axis.
5) The system enters the emergency stop state.
6) Controlled axis detachment is performed using the controlled axis detachment signal (DTCHx)
or parameter.
7) The servo off state is established using the servo off signal (SVFx).
1 Timing for canceling torque control
The processing for canceling torque control is based on PMC axis control and varies depending on
whether follow–up is to be performed (specified with parameter No. 1409, TRQFU). When follow–up
is to be performed, the torque control mode signal (TRQMx) is set to low and position control is re-
sumed immediately once any of the conditions for canceling torque control has been satisfied. Then,
execution is terminated as soon as the position deviation enters the effective range. When follow–up
is not to be performed, once any of the conditions for canceling torque control has been satisfied, the
torque control mode signal (TRQMx) is set to low, after which follow–up is started. Position control is
resumed once the position deviation falls below the value set with the cancel limit parameter (No.
7768). Then, execution is terminated as soon as the position deviation enters the effective range.
2 Command after torque control is canceled
After torque control mode is canceled, normal position control is applied. The position of the tool is,
however, not shifted because the position has also been controlled in torque control mode. The work-
piece coordinates are, however, shifted from the machine coordinates. So, this shift must be canceled
using, for example, the workpiece coordinate system preset function.
CAUTION When torque control is canceled while the tool is moving along a torque–controlled axis, the
machine is subjected to a jolt upon the return to position control. The faster the tool is
moving, the greater the jolt. Therefore, the tool should be decelerated or stopped before
canceling torque control.
NOTE 1 Torque control cannot be applied using PMC axis control based on the macro executor.
NOTE 2 If the tool is moved along a torque–controlled axis in torque control mode, specify follow–up
by setting parameter No. 1409 (TRQFU) to 1.