PA SDI-Drives Midi™ / Maxi™
Edition
07.44
Power Automation
2.3.2 Principle of Operation
The function “safe restart lock“ uses three digital inputs, to bring the drive in this state.
•
ENABLE – input
•
LOCK – input
•
EN-BRAKE – input
ed
ardware for about 0.5sec. After this time, the inputs force the drive in the safe state.
The ENABLE – input inhibits the control signals of the power stage.
-
stage. This is the second path to switch off the control signals of the power stage.
-
the axes, the enable input has to be set to “high” to be able to enable the drives.
combined in or – logic
utput
1/S2 is closed and symbolises the state “safe restart lock” after about 0.6 sec.
N
= 1 or the corresponding bit in
the control word) has to be set to enable the power stage.
All three signals have to be open or low, to enable the “safe restart lock” function. To
simplify the external emergency stop circuitry in the cabinet, the three inputs disable the
drive directly via microcontroller. The microcontroller decelerates the motor to zero spe
and disables the power stage. In parallel, the three inputs are switched-off delayed by
h
-
The LOCK – input switches off the supply voltage of the drivers of the IGBT power
The EN-BRAKE – input switches the 24V supply of the holding brake off. This
input can be set to high to release the holding brake for manual move of the
mechanics (in combination with
K-BRAKE
= 1) without loosing the safe restart
lock of the power stage. Even if no holding brake is connected to one or more of
The state of the supply voltage (on/off) of the drivers is fed back and
with the internal ENABLE signal and the internal EN-BRAKE signal.
Only if the three signals are in the safe state, the “SAFE LOCK” relay contact of o
S
When the inputs LOCK, ENABLE and EN-BRAKE are switched to high, the drive is not
enabled directly. In addition to that, a software enable (
K-E
LOCK or ENABLE
or EN-BRAKE
„SAFE“ Relay Output
(High = Contact Closed
Internal Enable
Software Enable
Speed Set Point
from Controller
Actual Speed
0.6 sec
0.1 sec
G-EMRAMP
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SDI Interface Manual
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