8. Platform¶
This section provides a description of the technologies used in the development of the GMT SWC System. It is the responsibility of the SWCS to define the platform that can meet operational requirements, thus most of the platform-related requirements are located in Hardware and Software Standard documents.
Several criteria play an important role in evaluating the platform technologies: technical, long-term availability, commercial and community support, and cost effectiveness. Fortunately, several choices are available both in the commercial and open source world to address the requirements of the GMT Software and Controls, making feasible several architecture platforms that will provide an adequate implementation. The SWCS platform is based on the use of well-established industrial standards, commercial off-the-shelf, and open source products while custom-built solutions are strongly discouraged. Design choices and prescribed standards come about through prototyping, benchmarking and evaluations. Other guidelines considered include:
- Avoiding proprietary or vendor lock-in options when several solutions based on open standards or even open source already exist,
- Avoiding niche market solutions when alternatives exist from competitive markets, especially where economy of scale plays an important role (e.g., industrial automation).
The GMT project office has evaluated [Filg12] several technologies as part of its preliminary design work, ranging from mature to more emergent. Preliminary evaluations show that a design based on widely available industrial open standards and open source products is capable of meeting the GMT Control System requirements. A set of guidelines and requirements regarding the use of these technologies in the project is included in the Software and Controls Handbook [Filg13b].
| Requirement | Statement |
|---|---|
| Software and Controls Standards | The GMT shall establish a set of Software and Controls Standards (GMT-SWC-REF-00029). |
| GMT System Health | The GMT shall provide continuous performance, status and system health monitoring. |
| Scheduled Maintenance Time | The SWCS shall be designed to facilitate maintenance and to comply with GMT Maintenance Time Budget (GMT-SE-DOC- 00420). |
| Critical Spares | The GMT shall provide spares for critical subsystem and instrument components as defined in the GMT Critical Spares Document (GMT-SE-DOC-00277). |
| Field Bus Standard | The GMT standard field bus shall be EtherCAT |
| Field Device Profiles | GMT device shall meet the standards defined in GMT-SWC- REF-00029. |
| Electronics Standards | The GMT shall comply with the Electronics Standards (GMT- SE-REF-00191) for the project. |
| GIR / OSS InfiniBand Lines | GMT shall provide TBD redundant sets of InfiniBand lines that run from the control building electronics room (data center) to junction boxes on the GIR/M2 using independent and separate cable routings. |
| Telecommunications | The GMT shall provide telecommunications between the facilities on the summit, the support site, the base facility, and connection to external commercial providers. |
| Computer Network | The GMT shall provide a computer network infrastructure on the summit to support telescope operation, the specified Operating Modes, required data transfer rates, and connection to the commercial provider. |
| Communication Protocols | The GMT shall define a standard set of software protocols and APIs that allow the communication with the required performance between different components. |
| GIR / OSS / Azimuth Disk Fiber Trunk Lines | GMT shall provide a redundant set of fiber trunk lines that run from the control building electronics room (data center) to junction boxes on the GIR / OSS / azimuth disk using independent and separate cable routings. |
| ASM Maximum Update Rate | The ASM shall have a maximum update rate in the Field Stabilization and Adaptive Optics modes of no less than 1 kHz. |
| ASM Actuator Response Time | The ASM actuator response time to a 1 micron step (reaching 80% of the commanded step size) shall be less than 0.5 ms. |
| NGWS Maximum Frame rate | The NGW shall operate at a minimum frame rate of 1.0 kHz [2.0 kHz goal]. |
| LTWS Detector Maximum Frame Rate | The LTWS Detector shall have a full frame rate (or equivalent) of greater or equal to 1000 frames per second. |
| AOS Embedded Control System | The AOS shall provide embedded Control Systems to control individual AOS component / devices. |
| Requirement | Statement |
|---|---|
| Connections to Instruments | Provide standardized connections to science instruments per the SWC Standards document (GMT-SWC-DOC-00029) |
| Electronics Standards | Comply with the electronics standards specifications per GMT-SE-REF-00191. |
| Software/Hardware Standards | Establish a set of software/hardware standards (GMT-SWC-REF-00029) for the project. |
| Software Standards | Follow the standards as stated in “SWC Software Standards” document (GMT-SWC-REF-00029). |
| Hardware Standards | Follow the standards as stated in “SWC Hardware Standards” document (GMT-SWC-REF-00029). |
| Communication Standards | Define a set of physical communication protocols to integrate its different components. |
| Critical Spares | Provide spares for critical subsystem and instrument components as defined in the GMT Critical Spares Document (GMT-SE-DOC-00277). |