Hamilton Sundstrand Company ACT2000 - Manual (Page 27)

2 UNDERSTANDING THE ACT2000
2.1 System Description
The ACT2000 is a closed-loop servo system containing motor control
electronics (MCE) and a brushless-DC-motor-driven ball-screw actuator.
The MCE contains analog-to-digital converters, a digital signal processor
(DSP), application specific integrated circuits (ASIC) and power supplies.
Figure 2-1 shows the system block diagram.
The MCE interfaces with the brushless DC motor, resolver and
thermistors. The MCE performs all necessary commutation, control and
status monitoring for the ACT2000.
The MCE provides the interface for the user’s engine control system and
power supply. The MCE incorporates analog inputs and outputs, discrete
inputs and outputs, and a serial communication interface. The MCE
provides signal conditioning for all external analog and discrete I/O, as
well as for the resolver and thermistor inputs from the actuator.
Note: The MCE analog and discrete signal interfaces are
electrically isolated. The serial communication interface is
optically isolated
2.2 Electrical Description
Power
The ACT2000 operates on an input voltage of 120 VDC (nominal) that is
provided by the user via an integral four-wire power harness. Refer to
Figure 1-6 or 1-7 for a typical connection. Refer to the General
Specification Summary Table in Section 1.2 for load specification values.
Control Signals
The ACT2000 accepts three two-wire external control signals via the
integral 17-wire signal harness. Refer to Figures 1-9 and 1-11 for typical
connections. Refer to the General Specification Summary Table in
Section 1.2 for signal specification values.
RUN Command
The user-provided RUN command is a discrete input. The RUN
command must be ON to enable the ACT2000 and actuator to perform
the homing sequence after resetting or powering up. The RUN command
CH. 2: UNDERSTANDING THE ACT2000 21