Mitsubishi Electric FR-A720-0.4K Instruction Manual page 226

Motor brake and stop operation
Orientation from stop
After turning on the orientation command (X22), turning on the start signal will increase the motor speed to the
orientation speed set in Pr. 351 Orientation speed, then orientation operation same as when "orientation during running"
is performed.
Note that, DC injection brake is operated if the position signal is within the DC injection brake start position.
• Action time chart
Main spindle speed (encoder)
Orientation command (X22)
Orientation completion signal (ORA)
Continuous multi-point orientation
Orientation command and orientation with STF/STR on
(Orientation in servo in status)
Main spindle speed (encoder)
Orientation command (X22)
Orientation completion signal (ORA)
• Read the position data at starting up of DY (refer to the FR-A7AX instruction manual).
• When the position signal is within the creep switchover position, the speed starts up to the creep speed not to the
orientation speed.
• When the position signal is not within the creep switchover position, the speed starts up tp the orientation speed.
• The DC injection brake is operated if the position signal is within the DC injection brake start position.
• 16-bit data with the FR-A7AX is valid only when the DY signal is on.
CAUTION
• The encoder should be coupled with the motor shaft or main spindle oriented with a speed ratio of 1 to 1 without any mechanical
looseness.
• DC injection brake operates when orientation stop is made. Release the DC injection brake in a time as short as possible (within
several seconds) since continuous operation of the DC injection brake will cause the motor to overheat, leading to burnout.
• Since no servo lock function is available after orientation stop, provide a holding mechanism such as mechanical brake or knock
pin when secure holding of a main spindle is required.
• To ensure correct positioning, the encoder must be set in the proper rotation direction and the A and B phases connected correctly.
• When the pulse signal from the encoder stops due to the encoder signal loss, etc. during orientation, the orientation fault signal
(ORM) may be output.
• When the DC injection brake is set to disabled using parameter for DC injection brake adjustment (voltage, frequency, speed, time)
when performing orientation control, orientation operation can not be completed. Always set the DC injection brake enabled.
• To terminate orientation, the start signal (STF or STR) must be first switched off and the orientation signal (X22) must be switched
off. As soon as this orientation signal is switched off, orientation control ends.(Depending on the Pr. 358 Servo torque selection
setting, orientation status continues if the orientation signal remains on even if DC injection brake is released at turning off of the
start signal. Therefore, the orientation status of the monitor function is not 0.)
• When retry function of Pr. 358 Servo torque selection is selected, this retry function is performed three times including the first orientation.
• When performing orientation control, make proper setting of Pr. 350 Stop position command selection and Pr. 360 16 bit data selection
(external position command selection). If the values set are incorrect, proper orientation control will not be performed.
• When Pr. 11 DC injection brake operation time = "8888" (DC injection brake external selection), DC injection brake does not operate if the
X13 signal is not turned on. Note that the DC injection brake is applied under orientation control regardless of the X13 signal status.
• When orientation control is exercised, PID control is invalid.
216
Pr. 351
Pr. 352
Start signal (STF, STR)
OFF
OFF
DC injection brake
Pr. 351
Pr. 352
Start signal (STF, STR)
Servo-in
DY
Position signal
Orientation speed (orientation switchover speed)
Creep speed (orientation deceleration ratio)
ON
ON
OFF
ON
OFF
ON
Orientation speed (orientation switchover speed)
Creep speed (orientation deceleration ratio)
ON
ON
Servo-in
ON
50ms or more is necessary
Position command latch
Time
OFF
OFF
OFF
OFF
ON
Position command latch