1. Back End Preliminary Design Review, 2002 April 24-25, Granada, Spain AtacamaLargeMillimeterArray DTS FO Hardware Design Bryan Anderson Jodrell Bank Observatory Co-authors: D.C. Brown, M. Bentley & R. McCool

2. DTS FO Hardware Design 25/08/2014 Back End Preliminary Design Review, 2002 April 24-25, Granada, Spain 2 ALMA Project Contents of Talk Fibre Interconnects (everywhere) Optical Receiver (correlator, AOS or OSF) Optical Transmitter (antenna) Optical Multiplexer-Monitor Module (antenna) Optical-Fibre Amplifier Module (AOS) Optical Demultiplexer-Switch Module (AOS/OSF) Monitor, Control and Safety

3. DTS FO Hardware Design 25/08/2014 Back End Preliminary Design Review, 2002 April 24-25, Granada, Spain 3 ALMA Project

4. DTS FO Hardware Design 25/08/2014 Back End Preliminary Design Review, 2002 April 24-25, Granada, Spain 4 ALMA Project

5. DTS FO Hardware Design 25/08/2014 Back End Preliminary Design Review, 2002 April 24-25, Granada, Spain 5 ALMA Project Optical Receiver

6. DTS FO Hardware Design 25/08/2014 Back End Preliminary Design Review, 2002 April 24-25, Granada, Spain 6 ALMA Project

7. DTS FO Hardware Design 25/08/2014 Back End Preliminary Design Review, 2002 April 24-25, Granada, Spain 7 ALMA Project

8. DTS FO Hardware Design 25/08/2014 Back End Preliminary Design Review, 2002 April 24-25, Granada, Spain 8 ALMA Project Optical-Fibre Amplifier Module Uses an oem EDFA module –20 dB gain, +17 dBm output power –Size: 100 x 100 x 15 mm –Interface: RS232, 25-pin connector, +5V @ 6 - 8W off 48V bus Plug-in with PIC controller, 8 per crate, 64 OFAM in 2 racks Keep-alive feedback from 4 sets of receivers

9. DTS FO Hardware Design 25/08/2014 Back End Preliminary Design Review, 2002 April 24-25, Granada, Spain 9 ALMA Project Optical Demux-Switch Module

10. DTS FO Hardware Design 25/08/2014 Back End Preliminary Design Review, 2002 April 24-25, Granada, Spain 10 ALMA Project Optical Demux-Switch Module Integrate demux-switch functions: hide 12 interconnects Make as plug-ins with PIC controller and power supply off 48V bus 4 ODSMs per crate 4 - 6 crates per rack Requires total of 3 - 4 racks

11. DTS FO Hardware Design 25/08/2014 Back End Preliminary Design Review, 2002 April 24-25, Granada, Spain 11 ALMA Project Monitor and Control Slaves: answer only Report the truth Remember calibrations and exceptions Parameters in non-volatile memory Monitor and control everything: no potentiometers Set/trip out philosophy for safety

12. DTS FO Hardware Design 25/08/2014 Back End Preliminary Design Review, 2002 April 24-25, Granada, Spain 12 ALMA Project Safety By design –Physical access restricted –Switch on under software control –Switch off via hardware or software Soft switching for transmitters? –Hardware keep-alives: OMMM to transmitters Receivers to optical amplifiers (256 twisted pairs!)