User Manual 08/2003 Edition

02.99 04.01
Closing the brake
when the ”pulse
enable” is
withdrawn
”Pulse enable”
Output signal
”control external
holding brake”
Speed setpoint
Speed actual value
Holding brake
Siemens AG 2003 All rights reserved
SIMODRIVE POSMO A User Manual (POS1) – 08.03 Edition
5.5 SIMODRIVE POSMO A functions
The ”pulse enable” is withdrawn when the following events occur:
STW.2 (operating condition / OFF 2) = 1/0 signal
STW.3 (operation enabled / operation inhibited) = 1/0 signal
A fault occurs, where it is no longer possible to brake in a controlled
fashion (e.g. encoder fault)
What happens if the ”pulse enable” is withdrawn?
When the pulse enable is withdrawn, the drive ”coasts” down and the
output signal ”open holding brake” is canceled.
The motor ”coasts” down until the brake becomes effective mechanically
and brings the motor to a standstill.
After the time taken for the brake to close, the drive is braked by the
motor holding brake.
1
0
1
0
1
0
Positioning mode OFF 2 – operating inhibit – fault
ÄÄÄÄÄ
ÄÄÄÄÄ
The drive ”coasts” down
The drive is braked by the
holding brake
Time
to close the holding brake
Fig. 5-17 Closing the brake: Behavior when withdrawing ”pulse enable”
!
5 Description of the Functions
Warning
When this type of braking is used, it subjects the holding brake to
mechanical wear and therefore should only be seldomly used.
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5-175
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