Aloha Observatory Design

Cabled Observatory Presentation

School of Ocean and Earth Science and TechnologyFebruary 2006

Observatory Overview

• The observatory is to provide supervisory command, control, and engineering status on data communications and system operation.

• The observatory is to provide services for customers. As needed, the customer will be able to control, time stamp and retrieve data in real time (or near real time) with his instrument.

• The observatory is to provide timing, power, and communications for up to two remote sub-observatory nodes.

• The observatory is designed for high reliability and redundancy.

Observatory Chassis

Circuit Comm IRIG-B FO to TP Remote

Breaker TCP/IP Switch Observatory

TCP/IP Switch Comm & Power

Port Server

(opposite side is mirror image)

Customer Capabilities

• The observatory is to provide power, communications and analog IRIG timing for each of six customers.

• The observatory is to protect/isolate each customer from failures/interference with other customers.

• The observatory is to connect on a predefined interface connector.

Customer Power

• The observatory is to provide 48VDC power up to a maximum of 75 watts (1.5 Amps) per customer.

• This power is a current trip level circuit breaker protected per customer. A power failure of any instrument will not effect another instrument or the system.

• The circuit breaker has 8 trip levels and off and is controlled by the supervisor not the customer.

Customer Power & Circuit Breaker

Customer Communication

• The customer’s instrument is provided one of three communications: (1) RS232, or (2) RS422, or (3) TCP/IP.

• The maximum rate currently is 230k baud per customer (460k baud should be available in ‘07)

• This communication is bidirectional and transparent to the user.

• Transparent: The customer can, over the internet, send and receive control and data real time with his instrument with no consideration of the medium.

Customer Communications

Port Server, Switch, & IRIG

Fiber Optic & Twisted Pair Switch

Customer Timing

• The observatory is to provide analog IRIG-B timing to the instrument.

• Usage of the IRIG-B timing is optional.• For customers with time critical data,

instruments must be designed to use the timing information.

• PC104 time card by jxi2, inc.• External VCXO oscillator with 16 bit DAC

for high stability

IRIG

Local Customer Connector• The connector interface is an Impulse® XSL 12 pin Dry Mate

(compatible with MARS OD pin configuration.) connector. Pin configuration as follows:– 1 n/a– 2 n/a– 3 RS422 RX- (Ethernet RX-)– 4 RS422 RX+ (Ethernet RX+)– 5 IRIG B timing– 6 IRIG B Return– 7 RS422 TX- (Ethernet TX-)– 8 RS422 TX+ (Ethernet TX+)– 9 48 VDC Return (Ground)– 10 48 VDC– 11 n/a– 12 n/a

Remote Sub-Observatory Capabilities

• The main observatory is to provide power, communications and timing for each remote sub-observatory.

• The main observatory is to protect/isolate each remote sub-observatory from failures or interference with customers.

• Each remote sub-observatory can be placed up to 1000 meters from the main observatory.

Remote Sub-Observatory Power

• The observatory is to provide 400VDC power up to a maximum of 200 watts (0.5 Amps) to the sub-observatory.

• This power is circuit breaker protected per remote sub-observatory. A power failure will not effect another instrument or the system.

• This is controlled by the supervisor not the customer.

Remote OBS & Circuit Breaker

Remote Sub-Observatory Communication

• The remote sub-observatory is TCP/IP.

• This communication is an extension of the main observatory and has the same transparent service to customers.

• Sub-observatories are for future expansion.

Remote Sub-Observatory Timing

• The observatory is to provide analog IRIG-B timing to the remote sub-observatory.

• The remote sub-observatory will buffer and subsequently provide analog IRIG-B timing to the remote sub-observatory customers, just as in the main observatory.

Supervisory Capabilities

• The observatory is to be provide continuous operational status of performance

• The observatory is to allocate resources for the customers.

• The observatory is to allocate resources for remote sub-observatories.

• The observatory is to allocate resources for power supply.

Supervisory Status

• The observatory is to provide engineering data on the observatory itself and the shunt regulator power supply.– 22 temperatures– 24 voltages– 14 currents– 8 circuit breakers status and trip levels– 8 shunt regulator operational status.

Supervisory Control

• The supervisor has control of customer power setting the trip level for the circuit breaker or turning off the power.

• The supervisor can monitor the customer’s instrument for ground faults.

• The supervisor can assign the primary and backup communication path

• The supervisor and control the operation configuration of the shunt regulator power supply.

• The supervisor has control of the remote observatory power setting the trip level for the circuit breaker or turning off the power.

Reliability and Redundancy

• The system is designed with consideration for high reliability and a reduction of single point failure.

• There are two 8 port TCP/IP switches or two 8 port serial communication port servers for customers. Only one of the two is sufficient for full system operation.

• There are two microcontrollers for each function. Only one is sufficient for full system operation.

• With six customer ports on each observatory, should one fail, the instrument could be moved to another port on the main or remote observatories.

Customer Redundancy

• Each customer has two data paths available within the observatory.

• A primary and a secondary.

• Each path going to a different port server or TCP/IP switch.

• The switching to the secondary path is controlled by the supervisor.

Control Redundancy

• The system has six microcontrollers (Rabbit 3000).– Two to control the six customers. Each controls three

customers and redundant control for the other three customers.

– Two for the IRIG-B timing with the high speed digital PC104 interface. One is primary and the second is redundant backup.

– Two for the remote observatories. Each controls one remote observatory and redundant control for the other.

No Fiber Pair Redundancy

• The HAW-4 cable has three fiber pairs in the cable at each main observatory. Only one pair is this observatory.

• There are two very high reliable fiber to twisted pair TCP/IP switches. One on each fiber pair.

• All communications can pass through either switch.

Power Supply Reliability

• There are six active shunt regulators providing 160 watts of power each.

• There are two inactive backup shunt regulators that can provide 160 watts of power each.

• Under supervisor control the backup units can be used to functionally replace any failed active shunt regulator.