While the inverter is generally enabled with the
Enable command, there is a choice of three control
commands to stop the drive, i.e.
-
Controller Inhibit
-
Rapid Stop
-
Stop.
In addition, the inverter can at any time be stopped via the input terminals, independent of the control
command which is being sent. This control option enables you to integrate the inverters into a
fieldbus-independent emergency stop concept.
The Enable Control Command
The
Enable control command enables the inverter via the fieldbus system. If the process ramp is
transmitted together with the
Enable command via the fieldbus system, this control command will
use the specified ramp value as acceleration ramp. If not, the inverter will use the typical ramp
generators
Ramp up for this control command, depending on the selected parameter and ramp
generator sets (Fig. 14).
For the
Enable control command to become active all three bits must be switched to Enable (110
bin
).
Fig. 14 shows the possible coding of the
Enable control command with 06hex.
The Controller Inhibit Control Command
The
Controller Inhibit control command allows you to disable the power output stages of the inverter
and thus make them become high-resistance. At the same time the inverter will activate the
mechanical motor brake causing the drive to stop immediately by way of mechanical braking. Motors
which are not fitted with a mechanical brake will coast to rest when this control command is used.
Fig. 13 shows that it suffices to set
bit 0: Controller Inhibit/Enable in the control word to initiate the
Controller Inhibit control command, as all other bits are irrelevant. Consequently, this control bit has
the highest priority in the control word.
The Rapid Stop Control Command
The
Rapid Stop control command causes the inverter to ramp down the currently active rapid stop
ramp. The set rapid stop ramps
P140
T13 Stop Ramp
(if parameter set 1 is active)
P141
T23 Stop Ramp
(if parameter set 2 is active)
will be active. The process ramp which might be specified via the fieldbus, has no effect on the rapid
stop! Reset
Bit 1: Enable/Rapid Stop to activate this control command (see Fig. 13).
2
1
2
1
2
1
Active
ramp generator set
Active
parameter set
Process
ramp via fieldbus
Fieldbus process ramp
No
Yes
MOVITRAC
setpoint processing
P131 T22 Ramp up = down*
)
*) Not for MOVITRAC 31.., size 0
®
P130 T12 Ramp up = down*
)
P123 T21 Ramp up
P120 T11 Ramp up
00324AEN
Fig. 14: Overview of the acceleration ramp options for the Enable control command
3
Inverter Control
with Process Data
MOVITRAC
®
31.. Fieldbus Unit Profile
27
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