12 - 8
Chapter 12 Expansion Control
The history of control mode switching is stored to the start history at request of
control mode switching. (Refer to Section 5.6.1 "System monitor data".)
Confirm the control mode with "control mode (high-order buffer memory address:
b2, b3)" of "[Md.108] Servo status". (Refer to Section 5.6.2 "Axis monitor data".)
Buffer memory address (High-order)
QD77MS2/QD77MS4 QD77MS16
[Md.108] Servo status: b2, b3
877+100n 2477+100n
n: Axis No.-1
Precautions at control mode switching
(1) The start complete signal and the positioning complete signal do not turn ON at
control mode switching.
(2) When "30: Control mode switch", "31: Speed control", or "32: Torque control" is
set in "[Md.26] Axis operation status", the BUSY signal turns ON.
(3) The motor speed might change momentarily at switching from the speed
control mode to the torque control mode. Therefore, it is recommended that the
control mode is switched from the speed control to the torque control after the
servomotors stop.
(4) Use the continuous operation to torque control mode for the usage such as
pressing a workpiece. Do not execute the continuous operation to torque
control in the speed control mode. Otherwise, an unexpected operation might
occur at switching to the position control mode.
(5) "In speed control flag" ([Md.31] Status: b0) does not turn ON during the speed
control mode in the speed-torque control.
Operation for "Position control mode ↔ Speed control mode switching"
When the position control mode is switched to the speed control mode, the
command speed immediately after the switching is the speed set in "speed initial
value selection (b8 to b11)" of "[Pr.90] Operation setting for speed-torque control
mode".
Speed initial value selection
([Pr.90]: b8 to b11)
Command speed to servo amplifier immediately after switching from
position control mode to speed control mode
0: Command speed The speed to servo amplifier immediately after switching is "0".
1: Feedback speed Motor speed received from servo amplifier at switching.
2: Automatic selection
The command speed is invalid due to the setting of continuous
operation to torque control mode. At control mode switching,
operation is the same as "0: Command speed".
When the speed control mode is switched to the position control mode, the
command position immediately after the switching is the current feed value at
switching.