The antenna control servo system (ACSS) is built to control a 32-mtr deep space antenna (DSN) system. The antenna axis configuration is an elevation over azimuth. AZ has steerability of 270 and EL has steerability is 0-90.
The system consists of ACU rack, ADU rack, DBR rack and portable antenna control unit (PACU).
ACSS is an antenna pointing system, controlled manually or automatically, which positions the antenna to receive the peak signal from a satellite. This ACSS described here is designed to position an antenna in azimuth, elevation axis of movement for the purpose of location and tracking the satellite of interest.
The ACSS uses the latest processor technology, providing accurate positioning, high reliability and maximum system flexibility. The system has capabilities for rapid access with RS 232 or RS-422 remote control applications.
The function of the system is to control the antenna movement in azimuth, elevation to track satellites through various functional modes. It continuously monitors and displays axis angle, the functional mode selected, and indicates errors like limits & interlocks if any.
The antenna control servo system (ACSS) is an intelligent and powerful control system which finds its applications on earth stationed antenna control for satellite tracking purpose in manual and advanced auto track modes.
| ADU | 4-channel analog inputs ±10V from ACU for drive amplifier interface. 8-channel analog outputs to ACU from drive amplifier. |
|---|---|
| Motor Interface | 2 motors each for azimuth and elevation axis interface. |
| Front Panel Interface | Potentiometer for speed selection on front panel of maintenance panel, Azimuth and elevation ON / OFF switch, command interface i.e., Enable, selection switches rocker switches. |
| Power Supply | 24V DC for drive amplifiers, motor brakes and interlocks. |
| Display | 4 analog panel meters, two each for AZ & EL axis on the maintenance panel. |
| Protection |
Circuit breakers at the input mains contactor choke and filter in series
with the power supply to the drive amplifier.
Fuse between Drive amplifier and Regenerative resistor. Circuit breakers at the input of the power supply. |
| AC Power Input |
415V AC 3Ø, 50Hz, ±10% tolerance.
230V AC 1Ø, 50Hz, ±10% tolerance. |
| Environmental |
Operating Temperature: 0 to 50 °C.
Storage Temperature: -20 to 70 °C. Relative Humidity: up to 95% non-condensing. |
| Bus Compatibility | cPCI Based |
|---|---|
| Type of Interfaces | |
| Analog Interface |
±10 VDC analog output with fine setting of 1 mV with analog isolation.
±10 VDC differential analog input with 16-channel interface with measurement accuracy of 0.5% of full range and analog isolation. |
| Digital Interface | 64-channel optically isolated interface with isolation level of 1.5 kV. |
| Encoder Interface | 2-channel EnDAT encoder interface. |
| Resolver Interface | 2-channel resolver interface with accuracy of 1 arc minute. |
| IRIG-B Interface | 1-channel IRIG-B interface with modulated signal levels from 250 mVp-p to 10 Vp-p and modulation ratio of 1:2.5 to 1:6. |
| Ethernet Interface | 10 / 100 Mbps Ethernet interface with 1:4 Ethernet switch for SGC, STC, and SRCU. |
| COM Port | RS-232 / RS-422 interface to ATE. |
| PACU Interface | RS-422 interface for Portable ACU. |
| Display | 6” / 9” graphical LCD. |
| Keyboard | Membrane keyboard suitable for the application. |
| AC Power Input | 230 V AC 1Ø, 50 Hz, ±10% tolerance. |
| Power Supply | SMPS-based power supply with low EMI / EMC. |
| External Interfaces | |
| Hand Wheels | 2-channel incremental encoder interface for AZ and EL manual movement. |
| PACU | RS-422 serial asynchronous interface. |
| Ethernet Hub / Switch | 4-port or 1:4 channel Ethernet switch interface. |
| ADU Interface | Analog and digital interface with Antenna Drive Unit. |
| Potentiometer Interface | 2-channel, 2-turn potentiometer interface from encoder boxes. Excitation voltage: 5 V or 10 V DC. |
| Tilt Sensor Interface | — |
| Wind Speed |
Operational: 60 kmph Survival: 160 kmph Stowing: 60–90 kmph Precision Tracking: 30 kmph (gusting up to 45 kmph) |
| Environmental |
Operating Temperature: 0 to 50 °C Storage Temperature: −20 to 70 °C Relative Humidity: up to 95% non-condensing |
| Mechanical Dimensions | 19”, 4U / 6U height, 400 mm to 600 mm in depth should be used. |
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