Siemens A1 User Manual
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Simple Applications
MICROMASTER Applications Handbook
23
Advanced Features:
025
Enable DC brake. The DC brake feature can be enabled to provide a
holding torque if required. See section 8.2.
holding torque if required. See section 8.2.
013/014
Increase/decrease frequency (Motor Potentiometer function).
099
BiCo Functionality. Many complex functions are possible.
Please consult the Parameter List for additional details.
Time
Possible control cycle using fixed frequencies, DC Braking, and
Variable Ramp Rates
Variable Ramp Rates
Output
Frequency
Frequency
Fixed Frequencies
Alternate Ramp time
selected via digital input
selected via digital input
DC Braking
selected via digital input
selected via digital input
Figure 5-3
Composite Control Cycle
5.5
Using the control outputs
There are several control outputs, which can be used to control external indicators
or warn of potential problems.
or warn of potential problems.
5.5.1
Analog Output (MICROMASTER MM440 only).
The analog output may be set to give several different indications as described in
parameter P0771. The output is 0-20 mA, but can be easily converted to a voltage
by fitting a resistor (500 ohms for 0-10 V for instance), and to 4-20 mA using the
scaling parameters such as P0778.
parameter P0771. The output is 0-20 mA, but can be easily converted to a voltage
by fitting a resistor (500 ohms for 0-10 V for instance), and to 4-20 mA using the
scaling parameters such as P0778.
5.5.2 Relays
An indicator relay is provided which may be programmed to give a variety of
indications using parameter P0731. The relay is often used to indicate set point
reached (P731=52.8), warning active (P731=52.7), output current exceeding a set
value (P731=53.3).
indications using parameter P0731. The relay is often used to indicate set point
reached (P731=52.8), warning active (P731=52.7), output current exceeding a set
value (P731=53.3).
The relays can be used to control an external brake. A timer function can be used
to start the inverter and release the brake as described in parameter P1216. In this
case, the relay must be suppressed and a contactor used to switch the brake itself.
See section 5.8.6.
to start the inverter and release the brake as described in parameter P1216. In this
case, the relay must be suppressed and a contactor used to switch the brake itself.
See section 5.8.6.
The relay contacts should be suppressed where inductive loads such as contactor
coils or electromagnetic brakes are switched.
coils or electromagnetic brakes are switched.