5-8
Motor, Mechanical Axis System, Measuring Systems
MPH-02, MPB-02, MPD-02
DOK-INDRV*-MP*-02VRS**-FK01-EN-P
You have to distinguish the following situations in the case of error:
•
Drive remains fully operational; "velocity command value reset with or
without ramp and filter" or "return motion" was set as the error reaction
(F2xxx, F4xxx, F6xxx error or NC-side drive enable reset in the case
of axis motion).
•
Drive defect (F8xxx error) or "torque or force disable of the motor
("coasting")" was set as the error reaction (F2xxx, F4xxx, F6xxx error
or NC-side drive enable reset in the case of axis motion).
Note:
The error reaction is set in parameter
P-0-0119, Best
possible deceleration
.
Errors can possibly cause damage to machines or drive components.
Depending on the application the following strategies are used for
minimizing damage:
In the case of servo drives that mostly drive linear axes with limited travel
distances, the protection of the machine is preferred to the drive in the
case of error situation 2. The controller, when set by the customer
(
P-0-0525, Holding brake control word
), therefore tries to realize the
shortest possible braking distances, even if this damages the holding
brake.
Main drives are rotary axes with "unlimited" travel distance, such as
spindle motors of milling and turning machines. Due to high speed and
high inertia most of these axes produce kinetic energies in operation that
often exceed the allowed energy absorption capacity of holding brakes
integrated in the motor. In the case of error situation 2, shutdown realized
by the holding brake only could destroy the brake very easily. Due to the
unlimited travel distance there normally isn’t any danger of damaging the
machine. The controller therefore, when determined by the customer
(P-0-0525), prevents the holding brake from applying and gives priority to
friction braking.
The required functionality of the holding brake, depending on the
application type of the drive (servo or main drive), is determined by the
respective bit in parameter P-0-0525.
If the drive cannot shut down the mechanical system within the time after
occurrence of the error entered in parameter S-0-0273, the motor holding
brake is applied after motor standstill, independent of the application
(servo or main drive).
Depending on the error reaction, motor standstill means:
•
falling below a velocity threshold (in the case of "velocity command
value reset" error reaction, with or without ramp)
•
target position reached and actual velocity value lower than the value
of
S-0-0124, Standstill window
(in the case of "return motion" error
reaction)
See also "Error Reactions" in chapter "Drive Functions"
Error Situation 1
Error Situation 2
Holding Brake Control for Servo
Drives
Holding Brake Control for Main
Drives
P-0-0525, Holding brake control
word
Holding Brake Control with Error
Situation 1
Courtesy
of
CMA/Flodyne/Hydradyne
▪
Motion
Control
▪
Hydraulic
▪
Pneumatic
▪
Electrical
▪
Mechanical
▪
(800)
426-5480
▪
www.cmafh.com