Vertical Axis Drop Prevention Control; Deceleration Control - Mitsubishi MELDAS HS Series Specifications And Instruction Manual

8-4-2 Vertical axis drop prevention control

The vertical axis drop prevention control is a function that prevents the vertical axis from dropping
due to a delay in the brake operation when an emergency stop occurs. The servo ready OFF will be
delayed by the time set in the parameter from when the emergency stop occurs. Thus, the no-control
time until the brakes activate can be eliminated.
<Setting and adjustment methods>
Set the time to delay the ready OFF in the vertical axis drop prevention time (SV048:EMGrt).
Read the current position on the CNC screen, and apply the emergency stop. Set the minimum
delay time where the axis does not drop.
Dynamic brakes
Motor brake control output (MBR)
Motor brake actual operation
Servo ready (READY)
No. Abbrev. Parameter name
SV048 EMGrt Vertical axis drop
prevention time
POINT
CAUTION
Chapter 8 Adjustment
Motor speed
OFF
ON
OFF
ON
OFF
ON
ON
OFF
Unit
Input the time to delay the ready OFF when an emergency stop
msec
occurs.
Increase the setting by 100 msec at a time and set the minimum
value where the axis does not drop.
1. This control will not function if the dynamic brake stop is selected with the
servo specifications (SV017: SPEC).
2. This control will not function if an alarm for which the dynamic brakes are
set as the stopping method occurs in an axis where vertical axis drop
prevention control is being carried out.
3. A drop amount of several µm to 10µm will remain due to the brake play.
1. Do not set a vertical axis drop prevention time longer than required. The
servo control and brakes could collide causing an overload alarm or
amplifier damage. There is no problem if the duplicate time is within
100msec.
2. During a power failure, vertical axis drop prevention control (including
deceleration control) exceeding 100msec cannot be guaranteed. The
control will change to the dynamic brakes.
Emergency stop occurrence

Deceleration control

Brake activation delay
EMGrt
Explanation
8–26
Time
Setting range
0 to 2000